Merge branch '1.2.x'

buildSrc/build.gradle

@@ -18,16 +18,16 @@ ext {
 }
 
 dependencies {
-	checkstyle "io.spring.javaformat:spring-javaformat-checkstyle:${javaFormatVersion}"
+	checkstyle("com.puppycrawl.tools:checkstyle:${checkstyle.toolVersion}")
+	checkstyle("io.spring.javaformat:spring-javaformat-checkstyle:${javaFormatVersion}")
+
 	implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}")
 	implementation("org.jetbrains.kotlin:kotlin-compiler-embeddable:${kotlinVersion}")
 	implementation("io.spring.javaformat:spring-javaformat-gradle-plugin:${javaFormatVersion}")
 }
 
 checkstyle {
-	def archive = configurations.checkstyle.filter { it.name.startsWith("spring-javaformat-checkstyle")}
-	config = resources.text.fromArchiveEntry(archive, "io/spring/javaformat/checkstyle/checkstyle.xml")
-	toolVersion = 8.11
+	toolVersion = "10.12.4"
 }
 
 gradlePlugin {

buildSrc/gradle.properties

@@ -1 +1 @@
-javaFormatVersion=0.0.28
+javaFormatVersion=0.0.41

buildSrc/src/main/java/org/springframework/graphql/build/ConventionsPlugin.java

@@ -23,6 +23,7 @@ import org.gradle.api.plugins.JavaBasePlugin;
 import org.gradle.api.publish.maven.plugins.MavenPublishPlugin;
 
 import org.springframework.graphql.build.conventions.DeploymentConventions;
+import org.springframework.graphql.build.conventions.FormattingConventions;
 import org.springframework.graphql.build.conventions.JavaConventions;
 import org.springframework.graphql.build.conventions.KotlinConventions;
 
@@ -42,6 +43,7 @@ public class ConventionsPlugin implements Plugin<Project> {
 
 	@Override
 	public void apply(Project project) {
+		new FormattingConventions().apply(project);
 		new JavaConventions().apply(project);
 		new KotlinConventions().apply(project);
 		new DeploymentConventions().apply(project);

buildSrc/src/main/java/org/springframework/graphql/build/conventions/FormattingConventions.java

@@ -16,7 +16,6 @@
 
 package org.springframework.graphql.build.conventions;
 
-import io.spring.javaformat.gradle.FormatTask;
 import io.spring.javaformat.gradle.SpringJavaFormatPlugin;
 import org.gradle.api.Project;
 import org.gradle.api.artifacts.DependencySet;
@@ -26,8 +25,7 @@ import org.gradle.api.plugins.quality.CheckstylePlugin;
 
 /**
  * Conventions that are applied in the presence of the {@link JavaBasePlugin}. When the
- * plugin is applied, the {@link SpringJavaFormatPlugin Spring Java Format} and
- * {@link CheckstylePlugin Checkstyle}.
+ * plugin is applied, {@link CheckstylePlugin Checkstyle} is applied and configured.
  *
  * @author Brian Clozel
  */
@@ -38,14 +36,14 @@ public class FormattingConventions {
 	}
 
 	private void applySpringJavaFormat(Project project) {
-		project.getPlugins().apply(SpringJavaFormatPlugin.class);
-		project.getTasks().withType(FormatTask.class, (formatTask) -> formatTask.setEncoding("UTF-8"));
 		project.getPlugins().apply(CheckstylePlugin.class);
 		CheckstyleExtension checkstyle = project.getExtensions().getByType(CheckstyleExtension.class);
-		checkstyle.setToolVersion("8.43");
+		checkstyle.setToolVersion("10.12.4");
 		checkstyle.getConfigDirectory().set(project.getRootProject().file("src/checkstyle"));
 		String version = SpringJavaFormatPlugin.class.getPackage().getImplementationVersion();
 		DependencySet checkstyleDependencies = project.getConfigurations().getByName("checkstyle").getDependencies();
+		checkstyleDependencies
+				.add(project.getDependencies().create("com.puppycrawl.tools:checkstyle:" + checkstyle.getToolVersion()));
 		checkstyleDependencies
 				.add(project.getDependencies().create("io.spring.javaformat:spring-javaformat-checkstyle:" + version));
 	}

spring-graphql-docs/src/main/java/org/springframework/graphql/docs/graalvm/server/GraphQlConfiguration.java

@@ -31,8 +31,8 @@ public class GraphQlConfiguration {
 	@Bean
 	RuntimeWiringConfigurer customWiringConfigurer(BookRepository bookRepository) { // <1>
 		DataFetcher<Book> dataFetcher = QuerydslDataFetcher.builder(bookRepository).single();
-		return wiringBuilder -> wiringBuilder
-				.type("Query", builder -> builder.dataFetcher("book", dataFetcher)); // <2>
+		return (wiringBuilder) -> wiringBuilder
+				.type("Query", (builder) -> builder.dataFetcher("book", dataFetcher)); // <2>
 	}
 
 }

spring-graphql-docs/src/main/java/org/springframework/graphql/docs/graphiql/configuration/GraphiQlConfiguration.java

@@ -28,13 +28,13 @@ import org.springframework.web.servlet.function.ServerResponse;
 @Configuration
 public class GraphiQlConfiguration {
 
-    @Bean
-    @Order(0)
-    public RouterFunction<ServerResponse> graphiQlRouterFunction() {
-        RouterFunctions.Builder builder = RouterFunctions.route();
-        ClassPathResource graphiQlPage = new ClassPathResource("graphiql/index.html"); // <1>
-        GraphiQlHandler graphiQLHandler = new GraphiQlHandler("/graphql", "", graphiQlPage); // <2>
-        builder = builder.GET("/graphiql", graphiQLHandler::handleRequest); // <3>
-        return builder.build(); // <4>
-    }
+	@Bean
+	@Order(0)
+	public RouterFunction<ServerResponse> graphiQlRouterFunction() {
+		RouterFunctions.Builder builder = RouterFunctions.route();
+		ClassPathResource graphiQlPage = new ClassPathResource("graphiql/index.html"); // <1>
+		GraphiQlHandler graphiQLHandler = new GraphiQlHandler("/graphql", "", graphiQlPage); // <2>
+		builder = builder.GET("/graphiql", graphiQLHandler::handleRequest); // <3>
+		return builder.build(); // <4>
+	}
 }

spring-graphql-docs/src/main/java/org/springframework/graphql/docs/server/interception/web/RequestErrorInterceptor.java

@@ -30,20 +30,20 @@ class RequestErrorInterceptor implements WebGraphQlInterceptor {
 
 	@Override
 	public Mono<WebGraphQlResponse> intercept(WebGraphQlRequest request, Chain chain) {
-		return chain.next(request).map(response -> {
+		return chain.next(request).map((response) -> {
 			if (response.isValid()) {
 				return response; // <1>
 			}
 
 			List<GraphQLError> errors = response.getErrors().stream() // <2>
-					.map(error -> {
+					.map((error) -> {
 						GraphqlErrorBuilder<?> builder = GraphqlErrorBuilder.newError();
 						// ...
 						return builder.build();
 					})
 					.toList();
 
-			return response.transform(builder -> builder.errors(errors).build()); // <3>
+			return response.transform((builder) -> builder.errors(errors).build()); // <3>
 		});
 	}
-}
+}

spring-graphql-docs/src/main/java/org/springframework/graphql/docs/server/interception/web/ResponseHeaderInterceptor.java

@@ -33,7 +33,7 @@ class ResponseHeaderInterceptor implements WebGraphQlInterceptor {
 
 	@Override
 	public Mono<WebGraphQlResponse> intercept(WebGraphQlRequest request, Chain chain) { // <2>
-		return chain.next(request).doOnNext(response -> {
+		return chain.next(request).doOnNext((response) -> {
 			String value = response.getExecutionInput().getGraphQLContext().get("cookieName");
 			ResponseCookie cookie = ResponseCookie.from("cookieName", value).build();
 			response.getResponseHeaders().add(HttpHeaders.SET_COOKIE, cookie.toString());

spring-graphql-docs/src/main/java/org/springframework/graphql/docs/server/transports/rsocket/GraphQlRSocketController.java

@@ -43,4 +43,4 @@ public class GraphQlRSocketController {
 	public Flux<Map<String, Object>> handleSubscription(Map<String, Object> payload) {
 		return this.handler.handleSubscription(payload);
 	}
-}
+}

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/AbstractDirectGraphQlTransport.java

@@ -41,7 +41,6 @@ import org.springframework.util.IdGenerator;
  * to a server-side GraphQL handler or service.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 abstract class AbstractDirectGraphQlTransport implements GraphQlTransport {
 
@@ -56,7 +55,7 @@ abstract class AbstractDirectGraphQlTransport implements GraphQlTransport {
 	@SuppressWarnings({"ConstantConditions", "unchecked"})
 	@Override
 	public Flux<GraphQlResponse> executeSubscription(GraphQlRequest request) {
-		return executeInternal(toExecutionRequest(request)).flatMapMany(response -> {
+		return executeInternal(toExecutionRequest(request)).flatMapMany((response) -> {
 			try {
 				Object data = response.getData();
 				AssertionErrors.assertTrue("Not a Publisher: " + data, data instanceof Publisher);
@@ -64,7 +63,7 @@ abstract class AbstractDirectGraphQlTransport implements GraphQlTransport {
 				List<ResponseError> errors = response.getErrors();
 				AssertionErrors.assertTrue("Subscription errors: " + errors, CollectionUtils.isEmpty(errors));
 
-				return Flux.from((Publisher<ExecutionResult>) data).map(executionResult ->
+				return Flux.from((Publisher<ExecutionResult>) data).map((executionResult) ->
 						new DefaultExecutionGraphQlResponse(response.getExecutionInput(), executionResult));
 			}
 			catch (AssertionError ex) {

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/AbstractGraphQlTesterBuilder.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.test.tester;
 
 import java.time.Duration;
@@ -35,7 +36,6 @@ import org.springframework.graphql.ResponseError;
 import org.springframework.graphql.client.AbstractGraphQlClientBuilder;
 import org.springframework.graphql.client.GraphQlClient;
 import org.springframework.graphql.client.GraphQlTransport;
-import org.springframework.graphql.support.CachingDocumentSource;
 import org.springframework.graphql.support.DocumentSource;
 import org.springframework.graphql.support.ResourceDocumentSource;
 import org.springframework.lang.Nullable;
@@ -51,6 +51,7 @@ import org.springframework.util.ClassUtils;
  * agnostic {@code GraphQlTester}. A transport specific extension can then wrap
  * this default tester by extending {@link AbstractDelegatingGraphQlTester}.
  *
+ * @param <B> the type of builder
  * @author Rossen Stoyanchev
  * @since 1.0.0
  * @see AbstractDelegatingGraphQlTester
@@ -86,7 +87,7 @@ public abstract class AbstractGraphQlTesterBuilder<B extends AbstractGraphQlTest
 
 	@Override
 	public B errorFilter(Predicate<ResponseError> predicate) {
-		this.errorFilter = (this.errorFilter != null ? errorFilter.and(predicate) : predicate);
+		this.errorFilter = (this.errorFilter != null) ? this.errorFilter.and(predicate) : predicate;
 		return self();
 	}
 
@@ -115,6 +116,7 @@ public abstract class AbstractGraphQlTesterBuilder<B extends AbstractGraphQlTest
 	/**
 	 * Allow transport-specific subclass builders to register a JSON Path
 	 * {@link MappingProvider} that matches the JSON encoding/decoding they use.
+	 * @param configurer a function applied to the JSON Path configuration
 	 */
 	protected void configureJsonPathConfig(Function<Configuration, Configuration> configurer) {
 		this.jsonPathConfig = configurer.apply(this.jsonPathConfig);
@@ -123,6 +125,7 @@ public abstract class AbstractGraphQlTesterBuilder<B extends AbstractGraphQlTest
 	/**
 	 * Build the default transport-agnostic client that subclasses can then wrap
 	 * with {@link AbstractDelegatingGraphQlTester}.
+	 * @param transport the graphql transport to use
 	 */
 	protected GraphQlTester buildGraphQlTester(GraphQlTransport transport) {
 
@@ -139,12 +142,12 @@ public abstract class AbstractGraphQlTesterBuilder<B extends AbstractGraphQlTest
 	 * initialize new builder instances with, based on "this" builder.
 	 */
 	protected Consumer<AbstractGraphQlTesterBuilder<?>> getBuilderInitializer() {
-		return builder -> {
+		return (builder) -> {
 			if (this.errorFilter != null) {
 				builder.errorFilter(this.errorFilter);
 			}
 			builder.documentSource(this.documentSource);
-			builder.configureJsonPathConfig(config -> this.jsonPathConfig);
+			builder.configureJsonPathConfig((config) -> this.jsonPathConfig);
 			builder.responseTimeout(this.responseTimeout);
 		};
 	}
@@ -153,6 +156,7 @@ public abstract class AbstractGraphQlTesterBuilder<B extends AbstractGraphQlTest
 	 * For cases where the Tester needs the {@link GraphQlTransport}, we can't use
 	 * transports directly since they are package private, but we can adapt the corresponding
 	 * {@link GraphQlClient} and adapt it to {@code GraphQlTransport}.
+	 * @param client the graphql client to use for extracting the transport
 	 */
 	protected static GraphQlTransport asTransport(GraphQlClient client) {
 		return new GraphQlTransport() {
@@ -180,7 +184,7 @@ public abstract class AbstractGraphQlTesterBuilder<B extends AbstractGraphQlTest
 	}
 
 
-	private static class Jackson2Configurer {
+	private static final class Jackson2Configurer {
 
 		private static final Class<?> defaultJsonProviderType;
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultExecutionGraphQlServiceTesterBuilder.java

@@ -37,7 +37,6 @@ import org.springframework.util.Assert;
  * wraps an {@code ExecutionGraphQlService}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultExecutionGraphQlServiceTesterBuilder
 		extends AbstractGraphQlTesterBuilder<DefaultExecutionGraphQlServiceTesterBuilder>
@@ -95,7 +94,7 @@ final class DefaultExecutionGraphQlServiceTesterBuilder
 
 	private void registerJsonPathMappingProvider() {
 		if (this.encoder != null && this.decoder != null) {
-			configureJsonPathConfig(config -> {
+			configureJsonPathConfig((config) -> {
 				EncoderDecoderMappingProvider provider = new EncoderDecoderMappingProvider(
 						Collections.singletonList(this.encoder), Collections.singletonList(this.decoder));
 				return config.mappingProvider(provider);
@@ -111,7 +110,7 @@ final class DefaultExecutionGraphQlServiceTesterBuilder
 	/**
 	 * Default {@link ExecutionGraphQlServiceTester} implementation.
 	 */
-	private static class DefaultExecutionGraphQlServiceTester
+	private static final class DefaultExecutionGraphQlServiceTester
 			extends AbstractDelegatingGraphQlTester implements ExecutionGraphQlServiceTester {
 
 		private final GraphQlServiceGraphQlTransport transport;

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultGraphQlTester.java

@@ -153,7 +153,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 		@SuppressWarnings("ConstantConditions")
 		@Override
 		public Response execute() {
-			return transport.execute(request()).map(response -> mapResponse(response, request())).block(responseTimeout);
+			return DefaultGraphQlTester.this.transport.execute(request()).map((response) -> mapResponse(response, request())).block(DefaultGraphQlTester.this.responseTimeout);
 		}
 
 		@Override
@@ -163,7 +163,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 
 		@Override
 		public Subscription executeSubscription() {
-			return () -> transport.executeSubscription(request()).map(result -> mapResponse(result, request()));
+			return () -> DefaultGraphQlTester.this.transport.executeSubscription(request()).map((result) -> mapResponse(result, request()));
 		}
 
 		private GraphQlRequest request() {
@@ -171,7 +171,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 		}
 
 		private DefaultResponse mapResponse(GraphQlResponse response, GraphQlRequest request) {
-			return new DefaultResponse(response, errorFilter, assertDecorator(request), jsonPathConfig);
+			return new DefaultResponse(response, DefaultGraphQlTester.this.errorFilter, assertDecorator(request), DefaultGraphQlTester.this.jsonPathConfig);
 		}
 
 		private Consumer<Runnable> assertDecorator(GraphQlRequest request) {
@@ -191,7 +191,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 	/**
 	 * Container for GraphQL response data and errors along with convenience methods.
 	 */
-	private final static class ResponseDelegate {
+	private static final class ResponseDelegate {
 
 		private final DocumentContext jsonDoc;
 
@@ -258,7 +258,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 		}
 
 		void consumeErrors(Consumer<List<ResponseError>> consumer) {
-			filterErrors(error -> true);
+			filterErrors((error) -> true);
 			consumer.accept(this.errors);
 		}
 
@@ -392,7 +392,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 			this.delegate.doAssert(() -> {
 				Object value = this.pathHelper.evaluateJsonPath(this.delegate.jsonContent());
 				AssertionErrors.assertNull(
-						"Expected null value at JSON path \"" + path + "\" but found " + value, value);
+						"Expected null value at JSON path \"" + this.path + "\" but found " + value, value);
 			});
 			return this;
 		}
@@ -464,7 +464,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 		}
 
 		private static String joinPaths(@Nullable String basePath, String path) {
-			return (basePath != null ? basePath + "." + path : path);
+			return (basePath != null) ? basePath + "." + path : path;
 		}
 
 
@@ -476,7 +476,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 			private final D entity;
 
 			protected DefaultEntity(TypeRefAdapter<D> typeAdapter) {
-				this.entity = delegate.read(jsonPath, typeAdapter);
+				this.entity = DefaultPath.this.delegate.read(DefaultPath.this.jsonPath, typeAdapter);
 			}
 
 			protected D getEntity() {
@@ -484,57 +484,57 @@ final class DefaultGraphQlTester implements GraphQlTester {
 			}
 
 			protected void doAssert(Runnable task) {
-				delegate.doAssert(task);
+				DefaultPath.this.delegate.doAssert(task);
 			}
 
 			protected String getPath() {
-				return path;
+				return DefaultPath.this.path;
 			}
 
 			@Override
 			public Path path(String path) {
-				return forPath(basePath, path, delegate);
+				return forPath(DefaultPath.this.basePath, path, DefaultPath.this.delegate);
 			}
 
 			@Override
 			public Path path(String path, Consumer<Path> pathConsumer) {
-				return forNestedPath(basePath, path, delegate, pathConsumer);
+				return forNestedPath(DefaultPath.this.basePath, path, DefaultPath.this.delegate, pathConsumer);
 			}
 
 			@Override
 			public <T extends S> T isEqualTo(Object expected) {
-				delegate.doAssert(() -> AssertionErrors.assertEquals(path, expected, this.entity));
+				DefaultPath.this.delegate.doAssert(() -> AssertionErrors.assertEquals(DefaultPath.this.path, expected, this.entity));
 				return self();
 			}
 
 			@Override
 			public <T extends S> T isNotEqualTo(Object other) {
-				delegate.doAssert(() -> AssertionErrors.assertNotEquals(path, other, this.entity));
+				DefaultPath.this.delegate.doAssert(() -> AssertionErrors.assertNotEquals(DefaultPath.this.path, other, this.entity));
 				return self();
 			}
 
 			@Override
 			public <T extends S> T isSameAs(Object expected) {
-				delegate.doAssert(() -> AssertionErrors.assertTrue(path, expected == this.entity));
+				DefaultPath.this.delegate.doAssert(() -> AssertionErrors.assertTrue(DefaultPath.this.path, expected == this.entity));
 				return self();
 			}
 
 			@Override
 			public <T extends S> T isNotSameAs(Object other) {
-				delegate.doAssert(() -> AssertionErrors.assertTrue(path, other != this.entity));
+				DefaultPath.this.delegate.doAssert(() -> AssertionErrors.assertTrue(DefaultPath.this.path, other != this.entity));
 				return self();
 			}
 
 			@Override
 			public <T extends S> T matches(Predicate<D> predicate) {
-				delegate
-						.doAssert(() -> AssertionErrors.assertTrue(path, predicate.test(this.entity)));
+				DefaultPath.this.delegate
+						.doAssert(() -> AssertionErrors.assertTrue(DefaultPath.this.path, predicate.test(this.entity)));
 				return self();
 			}
 
 			@Override
 			public <T extends S> T satisfies(Consumer<D> consumer) {
-				delegate.doAssert(() -> consumer.accept(this.entity));
+				DefaultPath.this.delegate.doAssert(() -> consumer.accept(this.entity));
 				return self();
 			}
 
@@ -557,7 +557,7 @@ final class DefaultGraphQlTester implements GraphQlTester {
 		private final class DefaultEntityList<E>
 				extends DefaultEntity<List<E>, EntityList<E>> implements EntityList<E> {
 
-			public DefaultEntityList(TypeRefAdapter<List<E>> typeAdapter) {
+			DefaultEntityList(TypeRefAdapter<List<E>> typeAdapter) {
 				super(typeAdapter);
 			}
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultHttpGraphQlTesterBuilder.java

@@ -33,7 +33,6 @@ import org.springframework.web.util.UriComponentsBuilder;
  * {@link WebTestClient.Builder}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultHttpGraphQlTesterBuilder
 		extends AbstractGraphQlTesterBuilder<DefaultHttpGraphQlTesterBuilder>
@@ -93,8 +92,8 @@ final class DefaultHttpGraphQlTesterBuilder
 	}
 
 	private void registerJsonPathMappingProvider() {
-		this.webTestClientBuilder.codecs(codecConfigurer ->
-				configureJsonPathConfig(config -> {
+		this.webTestClientBuilder.codecs((codecConfigurer) ->
+				configureJsonPathConfig((config) -> {
 					EncoderDecoderMappingProvider provider = new EncoderDecoderMappingProvider(codecConfigurer);
 					return config.mappingProvider(provider);
 				}));
@@ -105,7 +104,7 @@ final class DefaultHttpGraphQlTesterBuilder
 	 * Default {@link HttpGraphQlTester} that builds and uses a {@link WebTestClient}
 	 * for request execution.
 	 */
-	private static class DefaultHttpGraphQlTester extends AbstractDelegatingGraphQlTester implements HttpGraphQlTester {
+	private static final class DefaultHttpGraphQlTester extends AbstractDelegatingGraphQlTester implements HttpGraphQlTester {
 
 		private final WebTestClient webTestClient;
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultRSocketGraphQlTesterBuilder.java

@@ -113,9 +113,9 @@ public class DefaultRSocketGraphQlTesterBuilder
 	}
 
 	private void registerJsonPathMappingProvider() {
-		this.rsocketGraphQlClientBuilder.rsocketRequester(builder ->
-				builder.rsocketStrategies(strategiesBuilder ->
-						configureJsonPathConfig(config -> {
+		this.rsocketGraphQlClientBuilder.rsocketRequester((builder) ->
+				builder.rsocketStrategies((strategiesBuilder) ->
+						configureJsonPathConfig((config) -> {
 							RSocketStrategies strategies = strategiesBuilder.build();
 							List<Encoder<?>> encoders = strategies.encoders();
 							List<Decoder<?>> decoders = strategies.decoders();

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultTransportGraphQlTesterBuilder.java

@@ -27,7 +27,6 @@ import org.springframework.util.Assert;
  * Default {@link GraphQlTester.Builder} with a given, externally prepared transport.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultTransportGraphQlTesterBuilder
 		extends AbstractGraphQlTesterBuilder<DefaultTransportGraphQlTesterBuilder> {
@@ -50,7 +49,7 @@ final class DefaultTransportGraphQlTesterBuilder
 	/**
 	 * {@link GraphQlTester} with a given transport.
 	 */
-	private static class DefaultTransportGraphQlTester extends AbstractDelegatingGraphQlTester {
+	private static final class DefaultTransportGraphQlTester extends AbstractDelegatingGraphQlTester {
 
 		private final GraphQlTransport transport;
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultWebGraphQlTesterBuilder.java

@@ -34,7 +34,6 @@ import org.springframework.web.util.DefaultUriBuilderFactory;
  * {@link WebGraphQlHandler} for request execution.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultWebGraphQlTesterBuilder
 		extends AbstractGraphQlTesterBuilder<DefaultWebGraphQlTesterBuilder>
@@ -104,7 +103,7 @@ final class DefaultWebGraphQlTesterBuilder
 	}
 
 	private void registerJsonPathMappingProvider() {
-		configureJsonPathConfig(jsonPathConfig -> {
+		configureJsonPathConfig((jsonPathConfig) -> {
 			EncoderDecoderMappingProvider provider = new EncoderDecoderMappingProvider(this.codecConfigurer);
 			return jsonPathConfig.mappingProvider(provider);
 		});
@@ -114,7 +113,7 @@ final class DefaultWebGraphQlTesterBuilder
 	/**
 	 * Default {@link WebGraphQlTester} implementation.
 	 */
-	private static class DefaultWebGraphQlTester extends AbstractDelegatingGraphQlTester implements WebGraphQlTester {
+	private static final class DefaultWebGraphQlTester extends AbstractDelegatingGraphQlTester implements WebGraphQlTester {
 
 		private final WebGraphQlHandlerGraphQlTransport transport;
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/DefaultWebSocketGraphQlTesterBuilder.java

@@ -34,7 +34,6 @@ import org.springframework.web.reactive.socket.client.WebSocketClient;
  * {@link WebSocketGraphQlClient.Builder}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultWebSocketGraphQlTesterBuilder
 		extends AbstractGraphQlTesterBuilder<DefaultWebSocketGraphQlTesterBuilder>
@@ -108,8 +107,8 @@ final class DefaultWebSocketGraphQlTesterBuilder
 	}
 
 	private void registerJsonPathMappingProvider() {
-		this.graphQlClientBuilder.codecConfigurer(codecConfigurer -> {
-			configureJsonPathConfig(jsonPathConfig -> {
+		this.graphQlClientBuilder.codecConfigurer((codecConfigurer) -> {
+			configureJsonPathConfig((jsonPathConfig) -> {
 				EncoderDecoderMappingProvider provider = new EncoderDecoderMappingProvider(codecConfigurer);
 				return jsonPathConfig.mappingProvider(provider);
 			});
@@ -120,7 +119,7 @@ final class DefaultWebSocketGraphQlTesterBuilder
 	/**
 	 * Default {@link WebSocketGraphQlTester} implementation.
 	 */
-	private static class DefaultWebSocketGraphQlTester extends AbstractDelegatingGraphQlTester implements WebSocketGraphQlTester {
+	private static final class DefaultWebSocketGraphQlTester extends AbstractDelegatingGraphQlTester implements WebSocketGraphQlTester {
 
 		private final WebSocketGraphQlClient client;
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/EncoderDecoderMappingProvider.java

@@ -45,7 +45,6 @@ import org.springframework.util.MimeTypeUtils;
  * JSON Path {@link MappingProvider} that uses {@link Encoder} and {@link Decoder}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class EncoderDecoderMappingProvider implements MappingProvider {
 
@@ -60,29 +59,29 @@ final class EncoderDecoderMappingProvider implements MappingProvider {
 	/**
 	 * Create an instance with a {@link CodecConfigurer}.
 	 */
-	public EncoderDecoderMappingProvider(CodecConfigurer configurer) {
+	EncoderDecoderMappingProvider(CodecConfigurer configurer) {
 		this.encoder = findJsonEncoder(configurer);
 		this.decoder = findJsonDecoder(configurer);
 	}
 
 	/**
-	 * Create an instance with a List of encoders and decoders>
+	 * Create an instance with a List of encoders and decoders.
 	 */
-	public EncoderDecoderMappingProvider(List<Encoder<?>> encoders, List<Decoder<?>> decoders) {
+	EncoderDecoderMappingProvider(List<Encoder<?>> encoders, List<Decoder<?>> decoders) {
 		this.encoder = findJsonEncoder(encoders);
 		this.decoder = findJsonDecoder(decoders);
 	}
 
 	private static Encoder<?> findJsonEncoder(CodecConfigurer configurer) {
 		return findJsonEncoder(configurer.getWriters().stream()
-				.filter(writer -> writer instanceof EncoderHttpMessageWriter)
-				.map(writer -> ((EncoderHttpMessageWriter<?>) writer).getEncoder()));
+				.filter((writer) -> writer instanceof EncoderHttpMessageWriter)
+				.map((writer) -> ((EncoderHttpMessageWriter<?>) writer).getEncoder()));
 	}
 
 	private static Decoder<?> findJsonDecoder(CodecConfigurer configurer) {
 		return findJsonDecoder(configurer.getReaders().stream()
-				.filter(reader -> reader instanceof DecoderHttpMessageReader)
-				.map(reader -> ((DecoderHttpMessageReader<?>) reader).getDecoder()));
+				.filter((reader) -> reader instanceof DecoderHttpMessageReader)
+				.map((reader) -> ((DecoderHttpMessageReader<?>) reader).getDecoder()));
 	}
 
 	private static Encoder<?> findJsonEncoder(List<Encoder<?>> encoders) {
@@ -95,14 +94,14 @@ final class EncoderDecoderMappingProvider implements MappingProvider {
 
 	private static Encoder<?> findJsonEncoder(Stream<Encoder<?>> stream) {
 		return stream
-				.filter(encoder -> encoder.canEncode(MAP_TYPE, MediaType.APPLICATION_JSON))
+				.filter((encoder) -> encoder.canEncode(MAP_TYPE, MediaType.APPLICATION_JSON))
 				.findFirst()
 				.orElseThrow(() -> new IllegalArgumentException("No JSON Encoder"));
 	}
 
 	private static Decoder<?> findJsonDecoder(Stream<Decoder<?>> decoderStream) {
 		return decoderStream
-				.filter(decoder -> decoder.canDecode(MAP_TYPE, MediaType.APPLICATION_JSON))
+				.filter((decoder) -> decoder.canDecode(MAP_TYPE, MediaType.APPLICATION_JSON))
 				.findFirst()
 				.orElseThrow(() -> new IllegalArgumentException("No JSON Decoder"));
 	}

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/ExecutionGraphQlServiceTester.java

@@ -40,6 +40,7 @@ public interface ExecutionGraphQlServiceTester extends GraphQlTester {
 
 	/**
 	 * Create a {@link ExecutionGraphQlServiceTester} instance.
+	 * @param service the GraphQL service to use
 	 */
 	static ExecutionGraphQlServiceTester create(ExecutionGraphQlService service) {
 		return builder(service).build();
@@ -47,6 +48,7 @@ public interface ExecutionGraphQlServiceTester extends GraphQlTester {
 
 	/**
 	 * Return a builder for {@link ExecutionGraphQlServiceTester}.
+	 * @param service the GraphQL service to use
 	 */
 	static ExecutionGraphQlServiceTester.Builder<?> builder(ExecutionGraphQlService service) {
 		return new DefaultExecutionGraphQlServiceTesterBuilder(service);
@@ -55,12 +57,14 @@ public interface ExecutionGraphQlServiceTester extends GraphQlTester {
 
 	/**
 	 * Default {@link ExecutionGraphQlServiceTester.Builder} implementation.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends GraphQlTester.Builder<B> {
 
 		/**
 		 * Provide a {@code BiFunction} to help initialize the
 		 * {@link ExecutionInput} with.
+		 * @param configurer the function that initializes the execution input
 		 * @since 1.1.2
 		 * @see org.springframework.graphql.ExecutionGraphQlRequest#configureExecutionInput(BiFunction)
 		 */
@@ -69,12 +73,14 @@ public interface ExecutionGraphQlServiceTester extends GraphQlTester {
 		/**
 		 * Configure the JSON encoder to use for mapping response data to
 		 * higher level objects.
+		 * @param encoder the JSON encoder to use
 		 */
 		B encoder(Encoder<?> encoder);
 
 		/**
 		 * Configure the JSON decoder to use for mapping response data to
 		 * higher level objects.
+		 * @param decoder the JSON decoder to use
 		 */
 		B decoder(Decoder<?> decoder);
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/GraphQlServiceGraphQlTransport.java

@@ -34,7 +34,6 @@ import org.springframework.util.Assert;
  * {@code GraphQlTransport} that calls directly a {@link ExecutionGraphQlService}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class GraphQlServiceGraphQlTransport extends AbstractDirectGraphQlTransport {
 
@@ -53,11 +52,11 @@ final class GraphQlServiceGraphQlTransport extends AbstractDirectGraphQlTranspor
 	}
 
 
-	public ExecutionGraphQlService getGraphQlService() {
+	ExecutionGraphQlService getGraphQlService() {
 		return this.graphQlService;
 	}
 
-	public List<BiFunction<ExecutionInput, ExecutionInput.Builder, ExecutionInput>> getExecutionInputConfigurers() {
+	List<BiFunction<ExecutionInput, ExecutionInput.Builder, ExecutionInput>> getExecutionInputConfigurers() {
 		return this.executionInputConfigurers;
 	}
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/GraphQlTester.java

@@ -66,6 +66,7 @@ public interface GraphQlTester {
 	 * Variant of {@link #document(String)} that uses the given key to resolve
 	 * the GraphQL document from a file with the help of the configured
 	 * {@link Builder#documentSource(DocumentSource) DocumentSource}.
+	 * @param documentName the name of the document to send
 	 * @return spec for response assertions
 	 * @throws IllegalArgumentException if the documentName cannot be resolved
 	 * @throws AssertionError if the response status is not 200 (OK)
@@ -94,6 +95,7 @@ public interface GraphQlTester {
 
 	/**
 	 * A builder to create a {@link GraphQlTester} instance.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> {
 
@@ -111,6 +113,7 @@ public interface GraphQlTester {
 		 * <p>By default, this is set to {@link ResourceDocumentSource} with
 		 * classpath location {@code "graphql-test/"} and
 		 * {@link ResourceDocumentSource#FILE_EXTENSIONS} as extensions.
+		 * @param contentLoader the document content loader
 		 */
 		B documentSource(DocumentSource contentLoader);
 
@@ -130,6 +133,7 @@ public interface GraphQlTester {
 
 	/**
 	 * Declare options to gather input for a GraphQL request and execute it.
+	 * @param <T> the type of request
 	 */
 	interface Request<T extends Request<T>> {
 
@@ -311,7 +315,7 @@ public interface GraphQlTester {
 	}
 
 	/**
-	 * Contains a decoded entity and provides options to assert it
+	 * Contains a decoded entity and provides options to assert it.
 	 *
 	 * @param <D> the entity type
 	 * @param <S> the {@code Entity} spec type
@@ -320,6 +324,7 @@ public interface GraphQlTester {
 
 		/**
 		 * Verify the decoded entity is equal to the given value.
+		 * @param <T> the {@code Entity} spec type
 		 * @param expected the expected value
 		 * @return the {@code Entity} spec for further assertions
 		 */
@@ -327,6 +332,7 @@ public interface GraphQlTester {
 
 		/**
 		 * Verify the decoded entity is not equal to the given value.
+		 * @param <T> the {@code Entity} spec type
 		 * @param other the value to check against
 		 * @return the {@code Entity} spec for further assertions
 		 */
@@ -334,6 +340,7 @@ public interface GraphQlTester {
 
 		/**
 		 * Verify the decoded entity is the same instance as the given value.
+		 * @param <T> the {@code Entity} spec type
 		 * @param expected the expected value
 		 * @return the {@code Entity} spec for further assertions
 		 */
@@ -341,6 +348,7 @@ public interface GraphQlTester {
 
 		/**
 		 * Verify the decoded entity is not the same instance as the given value.
+		 * @param <T> the {@code Entity} spec type
 		 * @param other the value to check against
 		 * @return the {@code Entity} spec for further assertions
 		 */
@@ -348,6 +356,7 @@ public interface GraphQlTester {
 
 		/**
 		 * Verify the decoded entity matches the given predicate.
+		 * @param <T> the {@code Entity} spec type
 		 * @param predicate the predicate to apply
 		 * @return the {@code Entity} spec for further assertions
 		 */
@@ -355,6 +364,7 @@ public interface GraphQlTester {
 
 		/**
 		 * Verify the entity with the given {@link Consumer}.
+		 * @param <T> the {@code Entity} spec type
 		 * @param consumer the consumer to apply
 		 * @return the {@code Entity} spec for further assertions
 		 */

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/HttpGraphQlTester.java

@@ -37,6 +37,7 @@ public interface HttpGraphQlTester extends WebGraphQlTester {
 
 	/**
 	 * Create an {@link HttpGraphQlTester} that uses the given {@link WebTestClient}.
+	 * @param webTestClient the {@code WebTestClient} to use
 	 */
 	static HttpGraphQlTester create(WebTestClient webTestClient) {
 		return builder(webTestClient.mutate()).build();
@@ -45,6 +46,7 @@ public interface HttpGraphQlTester extends WebGraphQlTester {
 	/**
 	 * Return a builder to initialize an {@link HttpGraphQlTester} by creating
 	 * the underlying {@link WebTestClient} through the given builder.
+	 * @param webTestClientBuilder the {@code WebTestClient} builder to use
 	 */
 	static HttpGraphQlTester.Builder<?> builder(WebTestClient.Builder webTestClientBuilder) {
 		return new DefaultHttpGraphQlTesterBuilder(webTestClientBuilder);
@@ -53,6 +55,7 @@ public interface HttpGraphQlTester extends WebGraphQlTester {
 
 	/**
 	 * Builder for the GraphQL over HTTP tester.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends WebGraphQlTester.Builder<B> {
 
@@ -60,6 +63,7 @@ public interface HttpGraphQlTester extends WebGraphQlTester {
 		 * Customize the {@code WebTestClient} to use.
 		 * <p>Note that some properties of {@code WebTestClient.Builder} like the
 		 * base URL, headers, and codecs can be customized through this builder.
+		 * @param webClient a consumer that customizes the {@code WebClient} builder
 		 * @see #url(String)
 		 * @see #header(String, String...)
 		 * @see #codecConfigurer(Consumer)

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/RSocketGraphQlTester.java

@@ -64,6 +64,7 @@ public interface RSocketGraphQlTester extends GraphQlTester {
 
 	/**
 	 * Start with a given {@link #builder()}.
+	 * @param requesterBuilder the builder to use as a baseline
 	 */
 	static RSocketGraphQlTester.Builder<?> builder(RSocketRequester.Builder requesterBuilder) {
 		return new DefaultRSocketGraphQlTesterBuilder(requesterBuilder);
@@ -72,6 +73,7 @@ public interface RSocketGraphQlTester extends GraphQlTester {
 
 	/**
 	 * Builder for a GraphQL over RSocket tester.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends GraphQlTester.Builder<B> {
 
@@ -119,11 +121,12 @@ public interface RSocketGraphQlTester extends GraphQlTester {
 		 * <p>Note that some properties of {@code RSocketRequester.Builder} like the
 		 * data MimeType, and the underlying RSocket transport can be customized
 		 * through this builder.
+		 * @param requester a consumer that customizes the {@code RSocketRequester} through its builder
+		 * @return the same builder instance
 		 * @see #dataMimeType(MimeType)
 		 * @see #tcp(String, int)
 		 * @see #webSocket(URI)
 		 * @see #clientTransport(ClientTransport)
-		 * @return the same builder instance
 		 */
 		B rsocketRequester(Consumer<RSocketRequester.Builder> requester);
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/WebGraphQlHandlerGraphQlTransport.java

@@ -35,7 +35,6 @@ import org.springframework.lang.Nullable;
  * {@code GraphQlTransport} that calls directly a {@link WebGraphQlHandler}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class WebGraphQlHandlerGraphQlTransport extends AbstractDirectGraphQlTransport {
 
@@ -51,26 +50,26 @@ final class WebGraphQlHandlerGraphQlTransport extends AbstractDirectGraphQlTrans
 	WebGraphQlHandlerGraphQlTransport(
 			@Nullable URI url, HttpHeaders headers, WebGraphQlHandler handler, CodecConfigurer configurer) {
 
-		this.url = (url != null ? url : URI.create(""));
+		this.url = (url != null) ? url : URI.create("");
 		this.headers.addAll(headers);
 		this.graphQlHandler = handler;
 		this.codecConfigurer = configurer;
 	}
 
 
-	public URI getUrl() {
+	URI getUrl() {
 		return this.url;
 	}
 
-	public HttpHeaders getHeaders() {
+	HttpHeaders getHeaders() {
 		return this.headers;
 	}
 
-	public WebGraphQlHandler getGraphQlHandler() {
+	WebGraphQlHandler getGraphQlHandler() {
 		return this.graphQlHandler;
 	}
 
-	public CodecConfigurer getCodecConfigurer() {
+	CodecConfigurer getCodecConfigurer() {
 		return this.codecConfigurer;
 	}
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/WebGraphQlTester.java

@@ -43,6 +43,7 @@ public interface WebGraphQlTester extends GraphQlTester {
 
 	/**
 	 * Create a {@link WebGraphQlTester} instance.
+	 * @param graphQlHandler the web GraphQL handler to be tested
 	 */
 	static WebGraphQlTester create(WebGraphQlHandler graphQlHandler) {
 		return builder(graphQlHandler).build();
@@ -59,6 +60,7 @@ public interface WebGraphQlTester extends GraphQlTester {
 
 	/**
 	 * Common builder for Web {@code GraphQlTester} extensions.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends GraphQlTester.Builder<B> {
 
@@ -91,6 +93,7 @@ public interface WebGraphQlTester extends GraphQlTester {
 		/**
 		 * Configure the underlying {@code CodecConfigurer} to use for all JSON
 		 * encoding and decoding needs.
+		 * @param codecsConsumer a consumer that customizes the configured codecs
 		 */
 		B codecConfigurer(Consumer<CodecConfigurer> codecsConsumer);
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/WebSocketGraphQlTester.java

@@ -77,6 +77,7 @@ public interface WebSocketGraphQlTester extends WebGraphQlTester {
 
 	/**
 	 * Builder for a GraphQL over WebSocket tester.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends WebGraphQlTester.Builder<B> {
 

spring-graphql-test/src/main/java/org/springframework/graphql/test/tester/WebTestClientTransport.java

@@ -34,12 +34,11 @@ import org.springframework.util.Assert;
  * {@code GraphQlTransport} for GraphQL over HTTP via {@link WebTestClient}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class WebTestClientTransport implements GraphQlTransport {
 
 	private static final ParameterizedTypeReference<Map<String, Object>> MAP_TYPE =
-			new ParameterizedTypeReference<Map<String, Object>>() {};
+			new ParameterizedTypeReference<Map<String, Object>>() { };
 
 
 	private final WebTestClient webTestClient;
@@ -65,7 +64,7 @@ final class WebTestClientTransport implements GraphQlTransport {
 				.returnResult()
 				.getResponseBody();
 
-		responseMap = (responseMap != null ? responseMap : Collections.emptyMap());
+		responseMap = (responseMap != null) ? responseMap : Collections.emptyMap();
 		GraphQlResponse response = GraphQlTransport.createResponse(responseMap);
 		return Mono.just(response);
 	}

spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/GraphQlTesterTests.java

@@ -139,7 +139,7 @@ public class GraphQlTesterTests extends GraphQlTesterTestSupport {
 		assertThat(actual.getName()).isEqualTo("Luke Skywalker");
 
 		response.path("")
-				.entity(new ParameterizedTypeReference<Map<String, MovieCharacter>>() {})
+				.entity(new ParameterizedTypeReference<Map<String, MovieCharacter>>() { })
 				.isEqualTo(Collections.singletonMap("me", luke));
 
 		assertThat(getActualRequestDocument()).contains(document);
@@ -186,7 +186,7 @@ public class GraphQlTesterTests extends GraphQlTesterTestSupport {
 						"Request: document='{me {name, friends}}'");
 
 		response.path("me.friends")
-				.entityList(new ParameterizedTypeReference<MovieCharacter>() {})
+				.entityList(new ParameterizedTypeReference<MovieCharacter>() { })
 				.containsExactly(han, leia);
 
 		assertThat(getActualRequestDocument()).contains(document);

spring-graphql-test/src/test/java/org/springframework/graphql/test/tester/RSocketGraphQlTesterBuilderTests.java

@@ -117,7 +117,7 @@ public class RSocketGraphQlTesterBuilderTests {
 		assertThat(testDecoder.getLastValue()).isEqualTo(character);
 	}
 
-	
+
 	private static class BuilderSetup  {
 
 		private final MockExecutionGraphQlService graphQlService = new MockExecutionGraphQlService();

spring-graphql/src/main/java/org/springframework/graphql/GraphQlRequest.java

@@ -61,7 +61,7 @@ public interface GraphQlRequest {
 	/**
 	 * Convert the request to a {@link Map} as defined in
 	 * <a href="https://github.com/graphql/graphql-over-http/blob/main/spec/GraphQLOverHTTP.md">GraphQL over HTTP</a> and
-	 * <a href="https://github.com/enisdenjo/graphql-ws/blob/master/PROTOCOL.md">GraphQL over WebSocket</a>:
+	 * <a href="https://github.com/enisdenjo/graphql-ws/blob/master/PROTOCOL.md">GraphQL over WebSocket</a>.
 	 * <table>
 	 * <tr><th>Key</th><th>Value</th></tr>
 	 * <tr><td>query</td><td>{@link #getDocument() document}</td></tr>

spring-graphql/src/main/java/org/springframework/graphql/ResponseError.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2020-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package org.springframework.graphql;
 
 import java.util.List;

spring-graphql/src/main/java/org/springframework/graphql/client/AbstractGraphQlClientBuilder.java

@@ -47,6 +47,7 @@ import org.springframework.util.ClassUtils;
  * agnostic {@code GraphQlClient}. A transport specific extension can then wrap
  * this default tester by extending {@link AbstractDelegatingGraphQlClient}.
  *
+ * @param <B> the type of builder
  * @author Rossen Stoyanchev
  * @since 1.0.0
  * @see AbstractDelegatingGraphQlClient
@@ -123,6 +124,8 @@ public abstract class AbstractGraphQlClientBuilder<B extends AbstractGraphQlClie
 	 * Transport-specific subclasses can provide their JSON {@code Encoder} and
 	 * {@code Decoder} for use at the client level, for mapping response data
 	 * to some target entity type.
+	 * @param encoder the JSON encoder
+	 * @param decoder the JSON decoder
 	 */
 	protected void setJsonCodecs(Encoder<?> encoder, Decoder<?> decoder) {
 		this.jsonEncoder = encoder;
@@ -131,6 +134,7 @@ public abstract class AbstractGraphQlClientBuilder<B extends AbstractGraphQlClie
 
 	/**
 	 * Variant of {@link #setJsonCodecs} for setting each codec individually.
+	 * @param encoder the JSON encoder
 	 */
 	protected void setJsonEncoder(Encoder<?> encoder) {
 		this.jsonEncoder = encoder;
@@ -146,6 +150,7 @@ public abstract class AbstractGraphQlClientBuilder<B extends AbstractGraphQlClie
 
 	/**
 	 * Variant of {@link #setJsonCodecs} for setting each codec individually.
+	 * @param decoder the JSON decoder
 	 */
 	protected void setJsonDecoder(Decoder<?> decoder) {
 		this.jsonDecoder = decoder;
@@ -170,12 +175,13 @@ public abstract class AbstractGraphQlClientBuilder<B extends AbstractGraphQlClie
 	/**
 	 * Build the default transport-agnostic client that subclasses can then wrap
 	 * with {@link AbstractDelegatingGraphQlClient}.
+	 * @param transport the GraphQL transport to be used by the client
 	 */
 	protected GraphQlClient buildGraphQlClient(GraphQlTransport transport) {
 
 		if (jackson2Present) {
-			this.jsonEncoder = (this.jsonEncoder == null ? DefaultJackson2Codecs.encoder() : this.jsonEncoder);
-			this.jsonDecoder = (this.jsonDecoder == null ? DefaultJackson2Codecs.decoder() : this.jsonDecoder);
+			this.jsonEncoder = (this.jsonEncoder == null) ? DefaultJackson2Codecs.encoder() : this.jsonEncoder;
+			this.jsonDecoder = (this.jsonDecoder == null) ? DefaultJackson2Codecs.decoder() : this.jsonDecoder;
 		}
 
 		return new DefaultGraphQlClient(this.documentSource,
@@ -186,33 +192,33 @@ public abstract class AbstractGraphQlClientBuilder<B extends AbstractGraphQlClie
 	 * Return a {@code Consumer} to initialize new builders from "this" builder.
 	 */
 	protected Consumer<AbstractGraphQlClientBuilder<?>> getBuilderInitializer() {
-		return builder -> {
-			builder.interceptors(interceptorList -> interceptorList.addAll(interceptors));
-			builder.documentSource(documentSource);
+		return (builder) -> {
+			builder.interceptors((interceptorList) -> interceptorList.addAll(this.interceptors));
+			builder.documentSource(this.documentSource);
 			builder.setJsonCodecs(getEncoder(), getDecoder());
 		};
 	}
 
 	private Chain createExecuteChain(GraphQlTransport transport) {
 
-		Chain chain = request -> transport.execute(request)
-				.map(response -> new DefaultClientGraphQlResponse(request, response, getEncoder(), getDecoder()));
+		Chain chain = (request) -> transport.execute(request)
+				.map((response) -> new DefaultClientGraphQlResponse(request, response, getEncoder(), getDecoder()));
 
 		return this.interceptors.stream()
 				.reduce(GraphQlClientInterceptor::andThen)
-				.map(i -> (Chain) (request) -> i.intercept(request, chain))
+				.map((i) -> (Chain) (request) -> i.intercept(request, chain))
 				.orElse(chain);
 	}
 
 	private SubscriptionChain createSubscriptionChain(GraphQlTransport transport) {
 
-		SubscriptionChain chain = request -> transport
+		SubscriptionChain chain = (request) -> transport
 				.executeSubscription(request)
-				.map(response -> new DefaultClientGraphQlResponse(request, response, getEncoder(), getDecoder()));
+				.map((response) -> new DefaultClientGraphQlResponse(request, response, getEncoder(), getDecoder()));
 
 		return this.interceptors.stream()
 				.reduce(GraphQlClientInterceptor::andThen)
-				.map(i -> (SubscriptionChain) (request) -> i.interceptSubscription(request, chain))
+				.map((i) -> (SubscriptionChain) (request) -> i.interceptSubscription(request, chain))
 				.orElse(chain);
 	}
 

spring-graphql/src/main/java/org/springframework/graphql/client/AbstractGraphQlClientSyncBuilder.java

@@ -49,6 +49,7 @@ import org.springframework.util.ClassUtils;
  * agnostic {@code GraphQlClient}. A transport specific extension can then wrap
  * this default tester by extending {@link AbstractDelegatingGraphQlClient}.
  *
+ * @param <B> the type of builder
  * @author Rossen Stoyanchev
  * @since 1.3
  * @see AbstractDelegatingGraphQlClient
@@ -131,6 +132,7 @@ public abstract class AbstractGraphQlClientSyncBuilder<B extends AbstractGraphQl
 	 * Transport-specific subclasses can provide their JSON {@code Encoder} and
 	 * {@code Decoder} for use at the client level, for mapping response data
 	 * to some target entity type.
+	 * @param converter the message converter for JSON payloads
 	 */
 	protected void setJsonConverter(HttpMessageConverter<Object> converter) {
 		this.jsonConverter = converter;
@@ -140,12 +142,13 @@ public abstract class AbstractGraphQlClientSyncBuilder<B extends AbstractGraphQl
 	/**
 	 * Build the default transport-agnostic client that subclasses can then wrap
 	 * with {@link AbstractDelegatingGraphQlClient}.
+	 * @param transport the GraphQL transport to be used by the client
 	 */
 	protected GraphQlClient buildGraphQlClient(SyncGraphQlTransport transport) {
 
 		if (jackson2Present) {
-			this.jsonConverter = (this.jsonConverter == null ?
-					DefaultJacksonConverter.initialize() : this.jsonConverter);
+			this.jsonConverter = (this.jsonConverter == null) ?
+					DefaultJacksonConverter.initialize() : this.jsonConverter;
 		}
 
 		return new DefaultGraphQlClient(
@@ -156,9 +159,9 @@ public abstract class AbstractGraphQlClientSyncBuilder<B extends AbstractGraphQl
 	 * Return a {@code Consumer} to initialize new builders from "this" builder.
 	 */
 	protected Consumer<AbstractGraphQlClientSyncBuilder<?>> getBuilderInitializer() {
-		return builder -> {
-			builder.interceptors(interceptorList -> interceptorList.addAll(interceptors));
-			builder.documentSource(documentSource);
+		return (builder) -> {
+			builder.interceptors((interceptorList) -> interceptorList.addAll(this.interceptors));
+			builder.documentSource(this.documentSource);
 			builder.setJsonConverter(getJsonConverter());
 		};
 	}
@@ -168,14 +171,14 @@ public abstract class AbstractGraphQlClientSyncBuilder<B extends AbstractGraphQl
 		Encoder<?> encoder = HttpMessageConverterDelegate.asEncoder(getJsonConverter());
 		Decoder<?> decoder = HttpMessageConverterDelegate.asDecoder(getJsonConverter());
 
-		Chain chain = request -> {
+		Chain chain = (request) -> {
 			GraphQlResponse response = transport.execute(request);
 			return new DefaultClientGraphQlResponse(request, response, encoder, decoder);
 		};
 
 		return this.interceptors.stream()
 				.reduce(SyncGraphQlClientInterceptor::andThen)
-				.map(i -> (Chain) (request) -> i.intercept(request, chain))
+				.map((i) -> (Chain) (request) -> i.intercept(request, chain))
 				.orElse(chain);
 	}
 
@@ -185,7 +188,7 @@ public abstract class AbstractGraphQlClientSyncBuilder<B extends AbstractGraphQl
 	}
 
 
-	private static class DefaultJacksonConverter {
+	private static final class DefaultJacksonConverter {
 
 		static HttpMessageConverter<Object> initialize() {
 			return new MappingJackson2HttpMessageConverter();

spring-graphql/src/main/java/org/springframework/graphql/client/ClientGraphQlResponse.java

@@ -32,10 +32,12 @@ public interface ClientGraphQlResponse extends GraphQlResponse {
 	/**
 	 * {@inheritDoc}
 	 */
+	@Override
 	ClientResponseField field(String path);
 
 	/**
 	 * Decode the full response map to the given target type.
+	 * @param <D> the target type
 	 * @param type the target class
 	 * @return the decoded value, or never {@code null}
 	 * @throws FieldAccessException if the response is not {@link #isValid() valid}
@@ -44,7 +46,8 @@ public interface ClientGraphQlResponse extends GraphQlResponse {
 
 	/**
 	 * Variant of {@link #toEntity(Class)} with a {@link ParameterizedTypeReference}.
-	 * @param type the target type
+	 * @param <D> the target type
+	 * @param type the target parameterized type
 	 * @return the decoded value, or never {@code null}
 	 * @throws FieldAccessException if the response is not {@link #isValid() valid}
 	 */

spring-graphql/src/main/java/org/springframework/graphql/client/ClientResponseField.java

@@ -34,6 +34,7 @@ public interface ClientResponseField extends ResponseField {
 
 	/**
 	 * Decode the field to an entity of the given type.
+	 * @param <D> the entity type
 	 * @param entityType the type to convert to
 	 * @return the decoded entity, or {@code null} if the field is {@code null}
 	 * but otherwise there are no errors
@@ -46,12 +47,15 @@ public interface ClientResponseField extends ResponseField {
 
 	/**
 	 * Variant of {@link #toEntity(Class)} with a {@link ParameterizedTypeReference}.
+	 * @param <D> the entity type
+	 * @param entityType the type to convert to
 	 */
 	@Nullable
 	<D> D toEntity(ParameterizedTypeReference<D> entityType);
 
 	/**
 	 * Variant of {@link #toEntity(Class)} to decode to a list of entities.
+	 * @param <D> the entity type
 	 * @param elementType the type of elements in the list
 	 * @return the list of decoded entities, or an empty list if the field is
 	 * {@code null} but otherwise there are no errors
@@ -61,15 +65,16 @@ public interface ClientResponseField extends ResponseField {
 	 */
 	<D> List<D> toEntityList(Class<D> elementType);
 
-		/**
-		 * Variant of {@link #toEntity(Class)} to decode to a list of entities.
-		 * @param elementType the type of elements in the list
-		 * @return the list of decoded entities, or an empty list if the field is
-		 * {@code null} but otherwise there are no errors
-		 * @throws FieldAccessException if the target field is {@code null} and the
-		 * response is not {@link GraphQlResponse#isValid() valid} or the field has
-		 * {@link ResponseField#getErrors() errors}.
-		 */
+	/**
+	 * Variant of {@link #toEntity(Class)} to decode to a list of entities.
+	 * @param <D> the entity type
+	 * @param elementType the type of elements in the list
+	 * @return the list of decoded entities, or an empty list if the field is
+	 * {@code null} but otherwise there are no errors
+	 * @throws FieldAccessException if the target field is {@code null} and the
+	 * response is not {@link GraphQlResponse#isValid() valid} or the field has
+	 * {@link ResponseField#getErrors() errors}.
+	 */
 	<D> List<D> toEntityList(ParameterizedTypeReference<D> elementType);
 
 }

spring-graphql/src/main/java/org/springframework/graphql/client/CodecDelegate.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.client;
 
 import java.util.List;
@@ -37,7 +38,6 @@ import org.springframework.web.reactive.socket.WebSocketSession;
  * Helper class for encoding and decoding GraphQL messages.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class CodecDelegate {
 
@@ -60,14 +60,14 @@ final class CodecDelegate {
 
 	static Encoder<?> findJsonEncoder(CodecConfigurer configurer) {
 		return findJsonEncoder(configurer.getWriters().stream()
-				.filter(writer -> writer instanceof EncoderHttpMessageWriter)
-				.map(writer -> ((EncoderHttpMessageWriter<?>) writer).getEncoder()));
+				.filter((writer) -> writer instanceof EncoderHttpMessageWriter)
+				.map((writer) -> ((EncoderHttpMessageWriter<?>) writer).getEncoder()));
 	}
 
 	static Decoder<?> findJsonDecoder(CodecConfigurer configurer) {
 		return findJsonDecoder(configurer.getReaders().stream()
-				.filter(reader -> reader instanceof DecoderHttpMessageReader)
-				.map(reader -> ((DecoderHttpMessageReader<?>) reader).getDecoder()));
+				.filter((reader) -> reader instanceof DecoderHttpMessageReader)
+				.map((reader) -> ((DecoderHttpMessageReader<?>) reader).getDecoder()));
 	}
 
 	static Encoder<?> findJsonEncoder(List<Encoder<?>> encoders) {
@@ -80,26 +80,26 @@ final class CodecDelegate {
 
 	private static Encoder<?> findJsonEncoder(Stream<Encoder<?>> stream) {
 		return stream
-				.filter(encoder -> encoder.canEncode(MESSAGE_TYPE, MediaType.APPLICATION_JSON))
+				.filter((encoder) -> encoder.canEncode(MESSAGE_TYPE, MediaType.APPLICATION_JSON))
 				.findFirst()
 				.orElseThrow(() -> new IllegalArgumentException("No JSON Encoder"));
 	}
 
 	private static Decoder<?> findJsonDecoder(Stream<Decoder<?>> decoderStream) {
 		return decoderStream
-				.filter(decoder -> decoder.canDecode(MESSAGE_TYPE, MediaType.APPLICATION_JSON))
+				.filter((decoder) -> decoder.canDecode(MESSAGE_TYPE, MediaType.APPLICATION_JSON))
 				.findFirst()
 				.orElseThrow(() -> new IllegalArgumentException("No JSON Decoder"));
 	}
 
 
-	public CodecConfigurer getCodecConfigurer() {
+	CodecConfigurer getCodecConfigurer() {
 		return this.codecConfigurer;
 	}
 
 
 	@SuppressWarnings("unchecked")
-	public <T> WebSocketMessage encode(WebSocketSession session, GraphQlWebSocketMessage message) {
+	<T> WebSocketMessage encode(WebSocketSession session, GraphQlWebSocketMessage message) {
 
 		DataBuffer buffer = ((Encoder<T>) this.encoder).encodeValue(
 				(T) message, session.bufferFactory(), MESSAGE_TYPE, MimeTypeUtils.APPLICATION_JSON, null);
@@ -108,7 +108,7 @@ final class CodecDelegate {
 	}
 
 	@SuppressWarnings("ConstantConditions")
-	public GraphQlWebSocketMessage decode(WebSocketMessage webSocketMessage) {
+	GraphQlWebSocketMessage decode(WebSocketMessage webSocketMessage) {
 		DataBuffer buffer = DataBufferUtils.retain(webSocketMessage.getPayload());
 		return (GraphQlWebSocketMessage) this.decoder.decode(buffer, MESSAGE_TYPE, null, null);
 	}

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultClientGraphQlRequest.java

@@ -27,7 +27,6 @@ import org.springframework.lang.Nullable;
  * Default implementation of {@link ClientGraphQlRequest}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultClientGraphQlRequest extends DefaultGraphQlRequest implements ClientGraphQlRequest {
 

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultClientGraphQlResponse.java

@@ -26,7 +26,6 @@ import org.springframework.graphql.GraphQlResponse;
  * Default implementation of {@link ClientGraphQlResponse}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultClientGraphQlResponse extends ResponseMapGraphQlResponse implements ClientGraphQlResponse {
 

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultClientResponseField.java

@@ -40,7 +40,6 @@ import org.springframework.util.MimeTypeUtils;
  * support for decoding.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultClientResponseField implements ClientResponseField {
 
@@ -88,13 +87,13 @@ final class DefaultClientResponseField implements ClientResponseField {
 	@Override
 	public <D> List<D> toEntityList(Class<D> elementType) {
 		List<D> list = toEntity(ResolvableType.forClassWithGenerics(List.class, elementType));
-		return (list != null ? list : Collections.emptyList());
+		return (list != null) ? list : Collections.emptyList();
 	}
 
 	@Override
 	public <D> List<D> toEntityList(ParameterizedTypeReference<D> elementType) {
 		List<D> list = toEntity(ResolvableType.forClassWithGenerics(List.class, ResolvableType.forType(elementType)));
-		return (list != null ? list : Collections.emptyList());
+		return (list != null) ? list : Collections.emptyList();
 	}
 
 		@SuppressWarnings("unchecked")

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultGraphQlClient.java

@@ -36,7 +36,6 @@ import org.springframework.util.Assert;
  * Default, final {@link GraphQlClient} implementation for use with any transport.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultGraphQlClient implements GraphQlClient {
 
@@ -63,7 +62,7 @@ final class DefaultGraphQlClient implements GraphQlClient {
 		this.documentSource = documentSource;
 		this.blockingChain = blockingChain;
 		this.nonBlockingChain = adaptToNonBlockingChain(blockingChain, scheduler);
-		this.subscriptionChain = request -> Flux.error(new IllegalStateException("Subscriptions on supported"));
+		this.subscriptionChain = (request) -> Flux.error(new IllegalStateException("Subscriptions on supported"));
 		this.blockingTimeout = blockingTimeout;
 	}
 
@@ -87,14 +86,14 @@ final class DefaultGraphQlClient implements GraphQlClient {
 	private static GraphQlClientInterceptor.Chain adaptToNonBlockingChain(
 			SyncGraphQlClientInterceptor.Chain blockingChain, Scheduler scheduler) {
 
-		return request -> Mono.fromCallable(() -> blockingChain.next(request)).subscribeOn(scheduler);
+		return (request) -> Mono.fromCallable(() -> blockingChain.next(request)).subscribeOn(scheduler);
 	}
 
 	@SuppressWarnings("DataFlowIssue")
 	private static SyncGraphQlClientInterceptor.Chain adaptToBlockingChain(
 			GraphQlClientInterceptor.Chain executeChain, @Nullable Duration blockingTimeout) {
 
-		return (request -> blockingTimeout != null ?
+		return ((request) -> (blockingTimeout != null) ?
 				executeChain.next(request).block(blockingTimeout) : executeChain.next(request).block());
 	}
 
@@ -203,28 +202,28 @@ final class DefaultGraphQlClient implements GraphQlClient {
 		@Override
 		public ClientGraphQlResponse executeSync() {
 			Mono<ClientGraphQlRequest> mono = initRequest();
-			ClientGraphQlRequest request = (blockingTimeout != null ? mono.block(blockingTimeout) : mono.block());
-			return blockingChain.next(request);
+			ClientGraphQlRequest request = (DefaultGraphQlClient.this.blockingTimeout != null) ? mono.block(DefaultGraphQlClient.this.blockingTimeout) : mono.block();
+			return DefaultGraphQlClient.this.blockingChain.next(request);
 		}
 
 		@Override
 		public Mono<ClientGraphQlResponse> execute() {
-			return initRequest().flatMap(request -> nonBlockingChain.next(request)
+			return initRequest().flatMap((request) -> DefaultGraphQlClient.this.nonBlockingChain.next(request)
 					.onErrorResume(
-							ex -> !(ex instanceof GraphQlClientException),
-							ex -> Mono.error(new GraphQlTransportException(ex, request))));
+							(ex) -> !(ex instanceof GraphQlClientException),
+							(ex) -> Mono.error(new GraphQlTransportException(ex, request))));
 		}
 
 		@Override
 		public Flux<ClientGraphQlResponse> executeSubscription() {
-			return initRequest().flatMapMany(request -> subscriptionChain.next(request)
+			return initRequest().flatMapMany((request) -> DefaultGraphQlClient.this.subscriptionChain.next(request)
 					.onErrorResume(
-							ex -> !(ex instanceof GraphQlClientException),
-							ex -> Mono.error(new GraphQlTransportException(ex, request))));
+							(ex) -> !(ex instanceof GraphQlClientException),
+							(ex) -> Mono.error(new GraphQlTransportException(ex, request))));
 		}
 
 		private Mono<ClientGraphQlRequest> initRequest() {
-			return this.documentMono.map(document -> new DefaultClientGraphQlRequest(
+			return this.documentMono.map((document) -> new DefaultClientGraphQlRequest(
 					document, this.operationName, this.variables, this.extensions, this.attributes));
 		}
 
@@ -252,7 +251,7 @@ final class DefaultGraphQlClient implements GraphQlClient {
 				throw new FieldAccessException(
 						((DefaultClientGraphQlResponse) response).getRequest(), response, field);
 			}
-			return (field.getValue() != null ? field : null);
+			return (field.getValue() != null) ? field : null;
 		}
 
 	}
@@ -270,25 +269,25 @@ final class DefaultGraphQlClient implements GraphQlClient {
 		@Override
 		public <D> D toEntity(Class<D> entityType) {
 			ClientResponseField field = getValidField(this.response);
-			return (field != null ? field.toEntity(entityType) : null);
+			return (field != null) ? field.toEntity(entityType) : null;
 		}
 
 		@Override
 		public <D> D toEntity(ParameterizedTypeReference<D> entityType) {
 			ClientResponseField field = getValidField(this.response);
-			return (field != null ? field.toEntity(entityType) : null);
+			return (field != null) ? field.toEntity(entityType) : null;
 		}
 
 		@Override
 		public <D> List<D> toEntityList(Class<D> elementType) {
 			ClientResponseField field = getValidField(this.response);
-			return (field != null ? field.toEntityList(elementType) : Collections.emptyList());
+			return (field != null) ? field.toEntityList(elementType) : Collections.emptyList();
 		}
 
 		@Override
 		public <D> List<D> toEntityList(ParameterizedTypeReference<D> elementType) {
 			ClientResponseField field = getValidField(this.response);
-			return (field != null ? field.toEntityList(elementType) : Collections.emptyList());
+			return (field != null) ? field.toEntityList(elementType) : Collections.emptyList();
 		}
 
 	}
@@ -305,27 +304,27 @@ final class DefaultGraphQlClient implements GraphQlClient {
 
 		@Override
 		public <D> Mono<D> toEntity(Class<D> entityType) {
-			return this.responseMono.mapNotNull(this::getValidField).mapNotNull(field -> field.toEntity(entityType));
+			return this.responseMono.mapNotNull(this::getValidField).mapNotNull((field) -> field.toEntity(entityType));
 		}
 
 		@Override
 		public <D> Mono<D> toEntity(ParameterizedTypeReference<D> entityType) {
-			return this.responseMono.mapNotNull(this::getValidField).mapNotNull(field -> field.toEntity(entityType));
+			return this.responseMono.mapNotNull(this::getValidField).mapNotNull((field) -> field.toEntity(entityType));
 		}
 
 		@Override
 		public <D> Mono<List<D>> toEntityList(Class<D> elementType) {
-			return this.responseMono.map(response -> {
+			return this.responseMono.map((response) -> {
 				ClientResponseField field = getValidField(response);
-				return (field != null ? field.toEntityList(elementType) : Collections.emptyList());
+				return (field != null) ? field.toEntityList(elementType) : Collections.emptyList();
 			});
 		}
 
 		@Override
 		public <D> Mono<List<D>> toEntityList(ParameterizedTypeReference<D> elementType) {
-			return this.responseMono.map(response -> {
+			return this.responseMono.map((response) -> {
 				ClientResponseField field = getValidField(response);
-				return (field != null ? field.toEntityList(elementType) : Collections.emptyList());
+				return (field != null) ? field.toEntityList(elementType) : Collections.emptyList();
 			});
 		}
 
@@ -343,27 +342,27 @@ final class DefaultGraphQlClient implements GraphQlClient {
 
 		@Override
 		public <D> Flux<D> toEntity(Class<D> entityType) {
-			return this.responseFlux.mapNotNull(this::getValidField).mapNotNull(field -> field.toEntity(entityType));
+			return this.responseFlux.mapNotNull(this::getValidField).mapNotNull((field) -> field.toEntity(entityType));
 		}
 
 		@Override
 		public <D> Flux<D> toEntity(ParameterizedTypeReference<D> entityType) {
-			return this.responseFlux.mapNotNull(this::getValidField).mapNotNull(field -> field.toEntity(entityType));
+			return this.responseFlux.mapNotNull(this::getValidField).mapNotNull((field) -> field.toEntity(entityType));
 		}
 
 		@Override
 		public <D> Flux<List<D>> toEntityList(Class<D> elementType) {
-			return this.responseFlux.map(response -> {
+			return this.responseFlux.map((response) -> {
 				ClientResponseField field = getValidField(response);
-				return (field != null ? field.toEntityList(elementType) : Collections.emptyList());
+				return (field != null) ? field.toEntityList(elementType) : Collections.emptyList();
 			});
 		}
 
 		@Override
 		public <D> Flux<List<D>> toEntityList(ParameterizedTypeReference<D> elementType) {
-			return this.responseFlux.map(response -> {
+			return this.responseFlux.map((response) -> {
 				ClientResponseField field = getValidField(response);
-				return (field != null ? field.toEntityList(elementType) : Collections.emptyList());
+				return (field != null) ? field.toEntityList(elementType) : Collections.emptyList();
 			});
 		}
 

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultHttpGraphQlClientBuilder.java

@@ -33,7 +33,6 @@ import org.springframework.web.util.UriComponentsBuilder;
  * around a {@link WebClient.Builder}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultHttpGraphQlClientBuilder
 		extends AbstractGraphQlClientBuilder<DefaultHttpGraphQlClientBuilder>
@@ -105,7 +104,7 @@ final class DefaultHttpGraphQlClientBuilder
 	public HttpGraphQlClient build() {
 
 		// Pass the codecs to the parent for response decoding
-		this.webClientBuilder.codecs(configurer ->
+		this.webClientBuilder.codecs((configurer) ->
 				setJsonCodecs(
 						CodecDelegate.findJsonEncoder(configurer),
 						CodecDelegate.findJsonDecoder(configurer)));
@@ -139,6 +138,7 @@ final class DefaultHttpGraphQlClientBuilder
 			this.builderInitializer = builderInitializer;
 		}
 
+		@Override
 		public DefaultHttpGraphQlClientBuilder mutate() {
 			DefaultHttpGraphQlClientBuilder builder = new DefaultHttpGraphQlClientBuilder(this.webClient);
 			this.builderInitializer.accept(builder);

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultRSocketGraphQlClientBuilder.java

@@ -41,7 +41,6 @@ import org.springframework.util.MimeTypeUtils;
  * a {@link RSocketRequester.Builder}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultRSocketGraphQlClientBuilder
 		extends AbstractGraphQlClientBuilder<DefaultRSocketGraphQlClientBuilder>
@@ -134,9 +133,9 @@ final class DefaultRSocketGraphQlClientBuilder
 	public RSocketGraphQlClient build() {
 
 		// Pass the codecs to the parent for response decoding
-		this.requesterBuilder.rsocketStrategies(builder -> {
-			builder.decoders(decoders -> setJsonDecoder(CodecDelegate.findJsonDecoder(decoders)));
-			builder.encoders(encoders -> setJsonEncoder(CodecDelegate.findJsonEncoder(encoders)));
+		this.requesterBuilder.rsocketStrategies((builder) -> {
+			builder.decoders((decoders) -> setJsonDecoder(CodecDelegate.findJsonDecoder(decoders)));
+			builder.encoders((encoders) -> setJsonEncoder(CodecDelegate.findJsonEncoder(encoders)));
 		});
 
 		RSocketRequester requester;

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultSyncHttpGraphQlClientBuilder.java

@@ -34,7 +34,6 @@ import org.springframework.web.util.UriComponentsBuilder;
  * around a {@link RestClient.Builder}.
  *
  * @author Rossen Stoyanchev
- * @since 1.3
  */
 final class DefaultSyncHttpGraphQlClientBuilder
 		extends AbstractGraphQlClientSyncBuilder<DefaultSyncHttpGraphQlClientBuilder>
@@ -105,7 +104,7 @@ final class DefaultSyncHttpGraphQlClientBuilder
 	@Override
 	public HttpSyncGraphQlClient build() {
 
-		this.restClientBuilder.messageConverters(converters -> {
+		this.restClientBuilder.messageConverters((converters) -> {
 			HttpMessageConverter<Object> converter = HttpMessageConverterDelegate.findJsonConverter(converters);
 			setJsonConverter(converter);
 		});
@@ -141,6 +140,7 @@ final class DefaultSyncHttpGraphQlClientBuilder
 			this.builderInitializer = builderInitializer;
 		}
 
+		@Override
 		public DefaultSyncHttpGraphQlClientBuilder mutate() {
 			DefaultSyncHttpGraphQlClientBuilder builder = new DefaultSyncHttpGraphQlClientBuilder(this.restClient);
 			this.builderInitializer.accept(builder);

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultTransportGraphQlClientBuilder.java

@@ -26,7 +26,6 @@ import org.springframework.util.Assert;
  * Default {@link GraphQlClient.Builder} with a given, externally, prepared transport.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultTransportGraphQlClientBuilder
 		extends AbstractGraphQlClientBuilder<DefaultTransportGraphQlClientBuilder> {

spring-graphql/src/main/java/org/springframework/graphql/client/DefaultWebSocketGraphQlClientBuilder.java

@@ -20,7 +20,6 @@ import java.net.URI;
 import java.util.Arrays;
 import java.util.List;
 import java.util.function.Consumer;
-import java.util.stream.Collectors;
 
 import reactor.core.publisher.Mono;
 
@@ -37,7 +36,6 @@ import org.springframework.web.util.DefaultUriBuilderFactory;
  * {@code WebSocketGraphQlTransport}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class DefaultWebSocketGraphQlClientBuilder
 		extends AbstractGraphQlClientBuilder<DefaultWebSocketGraphQlClientBuilder>
@@ -130,14 +128,14 @@ final class DefaultWebSocketGraphQlClientBuilder
 	private WebSocketGraphQlClientInterceptor getInterceptor() {
 
 		List<WebSocketGraphQlClientInterceptor> interceptors = getInterceptors().stream()
-				.filter(interceptor -> interceptor instanceof WebSocketGraphQlClientInterceptor)
-				.map(interceptor -> (WebSocketGraphQlClientInterceptor) interceptor)
+				.filter((interceptor) -> interceptor instanceof WebSocketGraphQlClientInterceptor)
+				.map((interceptor) -> (WebSocketGraphQlClientInterceptor) interceptor)
 				.toList();
 
 		Assert.state(interceptors.size() <= 1,
 				"Only a single interceptor of type WebSocketGraphQlClientInterceptor may be configured");
 
-		return (!interceptors.isEmpty() ? interceptors.get(0) : new WebSocketGraphQlClientInterceptor() {});
+		return (!interceptors.isEmpty() ? interceptors.get(0) : new WebSocketGraphQlClientInterceptor() { });
 	}
 
 

spring-graphql/src/main/java/org/springframework/graphql/client/DgsGraphQlClient.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.client;
 
 import java.util.HashMap;
@@ -39,8 +40,8 @@ import org.springframework.util.Assert;
  * GraphQlClient client = ... ;
  * DgsGraphQlClient dgsClient = DgsGraphQlClient.create(client);
  *
- * List<Book> books = dgsClient.request(new BooksGraphQLQuery())
- * 		.projection(new BooksProjectionRoot<>().id().name())
+ * List&lt;Book&gt; books = dgsClient.request(new BooksGraphQLQuery())
+ * 		.projection(new BooksProjectionRoot&lt;&gt;().id().name())
  * 		.retrieveSync()
  * 		.toEntityList(Book.class);
  * </pre>
@@ -67,6 +68,7 @@ public final class DgsGraphQlClient {
 
 	/**
 	 * Start defining a GraphQL request for the given {@link GraphQLQuery}.
+	 * @param query the GraphQL query
 	 */
 	public RequestSpec request(GraphQLQuery query) {
 		return new RequestSpec(query);
@@ -80,7 +82,7 @@ public final class DgsGraphQlClient {
 	public static DgsGraphQlClient create(GraphQlClient client) {
 		return new DgsGraphQlClient(client);
 	}
-	
+
 
 	/**
 	 * Declare options to gather input for a GraphQL request and execute it.
@@ -105,6 +107,7 @@ public final class DgsGraphQlClient {
 
 		/**
 		 * Provide a {@link BaseProjectionNode} that defines the response selection set.
+		 * @param projectionNode the response selection set
 		 * @return ths same builder instance
 		 */
 		public RequestSpec projection(BaseProjectionNode projectionNode) {
@@ -114,20 +117,23 @@ public final class DgsGraphQlClient {
 
 		/**
 		 * Configure {@link Coercing} for serialization of scalar types.
+		 * @param scalarType the scalar type
+		 * @param coercing the coercing function for this scalar
 		 * @return ths same builder instance
 		 */
 		public RequestSpec coercing(Class<?> scalarType, Coercing<?, ?> coercing) {
-			this.coercingMap = (this.coercingMap != null ? this.coercingMap : new LinkedHashMap<>());
+			this.coercingMap = (this.coercingMap != null) ? this.coercingMap : new LinkedHashMap<>();
 			this.coercingMap.put(scalarType, coercing);
 			return this;
 		}
 
 		/**
 		 * Configure {@link Coercing} for serialization of scalar types.
+		 * @param coercingMap the map of coercing function
 		 * @return ths same builder instance
 		 */
 		public RequestSpec coercing(Map<Class<?>, Coercing<?, ?>> coercingMap) {
-			this.coercingMap = (this.coercingMap != null ? this.coercingMap : new LinkedHashMap<>());
+			this.coercingMap = (this.coercingMap != null) ? this.coercingMap : new LinkedHashMap<>();
 			this.coercingMap.putAll(coercingMap);
 			return this;
 		}
@@ -136,10 +142,12 @@ public final class DgsGraphQlClient {
 		 * Set a client request attribute.
 		 * <p>This is purely for client side request processing, i.e. available
 		 * throughout the {@link GraphQlClientInterceptor} chain but not sent.
+		 * @param name the attribute name
+		 * @param value the attribute value
 		 * @return ths same builder instance
 		 */
 		public RequestSpec attribute(String name, Object value) {
-			this.attributes = (this.attributes != null ? this.attributes : new HashMap<>());
+			this.attributes = (this.attributes != null) ? this.attributes : new HashMap<>();
 			this.attributes.put(name, value);
 			return this;
 		}
@@ -147,10 +155,11 @@ public final class DgsGraphQlClient {
 		/**
 		 * Manipulate the client request attributes. The map provided to the consumer
 		 * is "live", so the consumer can inspect and modify attributes accordingly.
+		 * @param attributesConsumer the consumer that will manipulate request attributes
 		 * @return ths same builder instance
 		 */
 		public RequestSpec attributes(Consumer<Map<String, Object>> attributesConsumer) {
-			this.attributes = (this.attributes != null ? this.attributes : new HashMap<>());
+			this.attributes = (this.attributes != null) ? this.attributes : new HashMap<>();
 			attributesConsumer.accept(this.attributes);
 			return this;
 		}
@@ -168,6 +177,7 @@ public final class DgsGraphQlClient {
 
 		/**
 		 * Variant of {@link #executeSync()} with explicit path relative to the "data" key.
+		 * @param path the JSON path relative to the "data" key
 		 */
 		public GraphQlClient.RetrieveSyncSpec retrieveSync(String path) {
 			return initRequestSpec().retrieveSync(path);
@@ -186,6 +196,7 @@ public final class DgsGraphQlClient {
 
 		/**
 		 * Variant of {@link #retrieve()} with explicit path relative to the "data" key.
+		 * @param path the JSON path relative to the "data" key
 		 */
 		public GraphQlClient.RetrieveSpec retrieve(String path) {
 			return initRequestSpec().retrieve(path);
@@ -237,15 +248,15 @@ public final class DgsGraphQlClient {
 			Assert.state(this.projectionNode != null || this.coercingMap == null,
 					"Coercing map provided without projection");
 
-			GraphQLQueryRequest request = (this.coercingMap != null ?
+			GraphQLQueryRequest request = (this.coercingMap != null) ?
 					new GraphQLQueryRequest(this.query, this.projectionNode, this.coercingMap) :
-					new GraphQLQueryRequest(this.query, this.projectionNode));
+					new GraphQLQueryRequest(this.query, this.projectionNode);
 
-			String operationName = (this.query.getName() != null ? this.query.getName() : null);
+			String operationName = (this.query.getName() != null) ? this.query.getName() : null;
 
-			return graphQlClient.document(request.serialize())
+			return DgsGraphQlClient.this.graphQlClient.document(request.serialize())
 					.operationName(operationName)
-					.attributes(map -> {
+					.attributes((map) -> {
 						if (this.attributes != null) {
 							map.putAll(this.attributes);
 						}

spring-graphql/src/main/java/org/springframework/graphql/client/FieldAccessException.java

@@ -38,6 +38,9 @@ public class FieldAccessException extends GraphQlClientException {
 
 	/**
 	 * Constructor with the request and response, and the accessed field.
+	 * @param request the client request
+	 * @param response  the client response
+	 * @param field the accessed field that caused the error
 	 */
 	public FieldAccessException(
 			ClientGraphQlRequest request, ClientGraphQlResponse response, ClientResponseField field) {

spring-graphql/src/main/java/org/springframework/graphql/client/GraphQlClient.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.client;
 
 import java.time.Duration;
@@ -64,6 +65,7 @@ public interface GraphQlClient {
 	 * Variant of {@link #document(String)} that uses the given key to resolve
 	 * the GraphQL document from a file with the help of the configured
 	 * {@link Builder#documentSource(DocumentSource) DocumentSource}.
+	 * @param name the document name
 	 * @throws IllegalArgumentException if the content could not be loaded
 	 */
 	RequestSpec documentName(String name);
@@ -90,7 +92,7 @@ public interface GraphQlClient {
 
 	/**
 	 * Base builder for creating and initializing a {@link GraphQlClient}.
-	 * @since 1.3
+	 * @param <B> the type of builder
 	 */
 	interface BaseBuilder<B extends BaseBuilder<B>> {
 
@@ -100,6 +102,7 @@ public interface GraphQlClient {
 		 * <p>By default, this is set to {@link ResourceDocumentSource} with
 		 * classpath location {@code "graphql-documents/"} and
 		 * {@link ResourceDocumentSource#FILE_EXTENSIONS} as extensions.
+		 * @param contentLoader the strategy for resolving documents by their names
 		 */
 		B documentSource(DocumentSource contentLoader);
 
@@ -125,7 +128,7 @@ public interface GraphQlClient {
 	/**
 	 * Builder to create a {@link GraphQlClient} instance with a
 	 * synchronous execution chain and transport.
-	 * @since 1.3
+	 * @param <B> the type of builder
 	 * @see SyncGraphQlTransport
 	 */
 	interface SyncBuilder<B extends SyncBuilder<B>> extends BaseBuilder<B> {
@@ -159,6 +162,7 @@ public interface GraphQlClient {
 	/**
 	 * Builder to create a {@link GraphQlClient} with a non-blocking execution
 	 * chain and transport.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends BaseBuilder<B> {
 
@@ -248,6 +252,7 @@ public interface GraphQlClient {
 		 * <pre>
 		 * client.document("..").executeSync()
 		 * </pre>
+		 * @param path the field path
 		 * @return a spec with decoding options
 		 * @throws FieldAccessException if the field has any field errors,
 		 * including errors at, above or below the field path.
@@ -261,6 +266,7 @@ public interface GraphQlClient {
 		 * <pre>
 		 * client.document("..").execute().map(response -> ...)
 		 * </pre>
+		 * @param path the field path
 		 * @return a spec with decoding options
 		 * @throws FieldAccessException if the field has any field errors,
 		 * including errors at, above or below the field path.
@@ -274,6 +280,7 @@ public interface GraphQlClient {
 		 * <pre>
 		 * client.document("..").executeSubscription().map(response -> ...)
 		 * </pre>
+		 * @param path the field path
 		 * @return a spec with decoding options
 		 */
 		RetrieveSubscriptionSpec retrieveSubscription(String path);
@@ -318,12 +325,12 @@ public interface GraphQlClient {
 
 	/**
 	 * Declares options to decode a field in a single response.
-	 * @since 1.3
 	 */
 	interface RetrieveSyncSpec {
 
 		/**
 		 * Decode the field to an entity of the given type.
+		 * @param <D> the type to convert to
 		 * @param entityType the type to convert to
 		 * @return the entity or null if the field is {@code null} and has no errors.
 		 * @throws FieldAccessException in case of {@link ResponseField field
@@ -335,18 +342,23 @@ public interface GraphQlClient {
 
 		/**
 		 * Variant of {@link #toEntity(Class)} with a {@link ParameterizedTypeReference}.
+		 * @param <D> the type to convert to
+		 * @param entityType the type to convert to
 		 */
 		@Nullable
 		<D> D toEntity(ParameterizedTypeReference<D> entityType);
 
 		/**
 		 * Variant of {@link #toEntity(Class)} to decode to a List of entities.
+		 * @param <D> the type to convert to
 		 * @param elementType the type of elements in the list
 		 */
 		<D> List<D> toEntityList(Class<D> elementType);
 
 		/**
 		 * Variant of {@link #toEntityList(Class)} with a {@link ParameterizedTypeReference}.
+		 * @param <D> the type to convert to
+		 * @param elementType the type of elements in the list
 		 */
 		<D> List<D> toEntityList(ParameterizedTypeReference<D> elementType);
 
@@ -360,6 +372,7 @@ public interface GraphQlClient {
 
 		/**
 		 * Decode the field to an entity of the given type.
+		 * @param <D> the type to convert to
 		 * @param entityType the type to convert to
 		 * @return {@code Mono} with the decoded entity; completes with
 		 * {@link FieldAccessException} in case of {@link ResponseField field
@@ -371,17 +384,22 @@ public interface GraphQlClient {
 
 		/**
 		 * Variant of {@link #toEntity(Class)} with a {@link ParameterizedTypeReference}.
+		 * @param <D> the entity type
+		 * @param entityType the type to convert to
 		 */
 		<D> Mono<D> toEntity(ParameterizedTypeReference<D> entityType);
 
 		/**
 		 * Variant of {@link #toEntity(Class)} to decode to a List of entities.
+		 * @param <D> the type to convert to
 		 * @param elementType the type of elements in the list
 		 */
 		<D> Mono<List<D>> toEntityList(Class<D> elementType);
 
 		/**
 		 * Variant of {@link #toEntityList(Class)} with a {@link ParameterizedTypeReference}.
+		 * @param <D> the type to convert to
+		 * @param elementType the type of elements in the list
 		 */
 		<D> Mono<List<D>> toEntityList(ParameterizedTypeReference<D> elementType);
 
@@ -395,6 +413,7 @@ public interface GraphQlClient {
 
 		/**
 		 * Decode the field to an entity of the given type.
+		 * @param <D> the type to convert to
 		 * @param entityType the type to convert to
 		 * @return {@code Mono} with the decoded entity; completes with
 		 * {@link FieldAccessException} in case of {@link ResponseField field
@@ -406,20 +425,25 @@ public interface GraphQlClient {
 
 		/**
 		 * Variant of {@link #toEntity(Class)} with a {@link ParameterizedTypeReference}.
+		 * @param <D> the type to convert to
+		 * @param entityType the type to convert to
 		 */
 		<D> Flux<D> toEntity(ParameterizedTypeReference<D> entityType);
 
 		/**
 		 * Variant of {@link #toEntity(Class)} to decode each response to a List of entities.
+		 * @param <D> the type to convert to
 		 * @param elementType the type of elements in the list
 		 */
 		<D> Flux<List<D>> toEntityList(Class<D> elementType);
 
 		/**
 		 * Variant of {@link #toEntity(Class)} to decode each response to a List of entities.
+		 * @param <D> the type to convert to
+		 *           @param elementType the type of elements in the list
 		 */
 		<D> Flux<List<D>> toEntityList(ParameterizedTypeReference<D> elementType);
 
 	}
 
-}
+}

spring-graphql/src/main/java/org/springframework/graphql/client/GraphQlClientException.java

@@ -36,6 +36,9 @@ public class GraphQlClientException extends NestedRuntimeException {
 
 	/**
 	 * Constructor with a message, optional cause, and the request details.
+	 * @param message the exception message to use
+	 * @param cause the original cause for the client exception
+	 * @param request the request that failed
 	 */
 	public GraphQlClientException(String message, @Nullable Throwable cause, GraphQlRequest request) {
 		super(message, cause);

spring-graphql/src/main/java/org/springframework/graphql/client/GraphQlClientInterceptor.java

@@ -67,13 +67,13 @@ public interface GraphQlClientInterceptor {
 			@Override
 			public Mono<ClientGraphQlResponse> intercept(ClientGraphQlRequest request, Chain chain) {
 				return GraphQlClientInterceptor.this.intercept(
-						request, nextRequest -> interceptor.intercept(nextRequest, chain));
+						request, (nextRequest) -> interceptor.intercept(nextRequest, chain));
 			}
 
 			@Override
 			public Flux<ClientGraphQlResponse> interceptSubscription(ClientGraphQlRequest request, SubscriptionChain chain) {
 				return GraphQlClientInterceptor.this.interceptSubscription(
-						request, nextRequest -> interceptor.interceptSubscription(nextRequest, chain));
+						request, (nextRequest) -> interceptor.interceptSubscription(nextRequest, chain));
 			}
 		};
 	}

spring-graphql/src/main/java/org/springframework/graphql/client/GraphQlTransport.java

@@ -63,6 +63,7 @@ public interface GraphQlTransport {
 	/**
 	 * Factory method to create {@link GraphQlResponse} from a GraphQL response
 	 * map for use in transport implementations.
+	 * @param responseMap the GraphQL response map
 	 */
 	static GraphQlResponse createResponse(Map<String, Object> responseMap) {
 		return new ResponseMapGraphQlResponse(responseMap);

spring-graphql/src/main/java/org/springframework/graphql/client/GraphQlTransportException.java

@@ -32,6 +32,8 @@ public class GraphQlTransportException extends GraphQlClientException {
 
 	/**
 	 * Constructor with a default message.
+	 * @param cause the original cause of the transport error
+	 * @param request the request that failed at the transport level
 	 */
 	public GraphQlTransportException(@Nullable Throwable cause, GraphQlRequest request) {
 		super("GraphQlTransport error: " + cause.getMessage(), cause, request);
@@ -39,6 +41,9 @@ public class GraphQlTransportException extends GraphQlClientException {
 
 	/**
 	 * Constructor with a given message.
+	 * @param message the exception message to use
+	 * @param cause the original cause of the transport error
+	 * @param request the request that failed at the transport level
 	 */
 	public GraphQlTransportException(String message, @Nullable Throwable cause, GraphQlRequest request) {
 		super(message, cause, request);

spring-graphql/src/main/java/org/springframework/graphql/client/HttpGraphQlClient.java

@@ -36,6 +36,7 @@ public interface HttpGraphQlClient extends WebGraphQlClient {
 
 	/**
 	 * Create an {@link HttpGraphQlClient} that uses the given {@link WebClient}.
+	 * @param webClient the {@code WebClient} to use for sending HTTP requests
 	 */
 	static HttpGraphQlClient create(WebClient webClient) {
 		return builder(webClient.mutate()).build();
@@ -51,6 +52,7 @@ public interface HttpGraphQlClient extends WebGraphQlClient {
 	/**
 	 * Variant of {@link #builder()} with a pre-configured {@code WebClient}
 	 * to mutate and customize further through the returned builder.
+	 * @param webClient the {@code WebClient} to use for sending HTTP requests
 	 */
 	static Builder<?> builder(WebClient webClient) {
 		return builder(webClient.mutate());
@@ -59,6 +61,7 @@ public interface HttpGraphQlClient extends WebGraphQlClient {
 	/**
 	 * Variant of {@link #builder()} with a pre-configured {@code WebClient}
 	 * to mutate and customize further through the returned builder.
+	 * @param webClientBuilder the {@code WebClient.Builder} to use for building the HTTP client
 	 */
 	static Builder<?> builder(WebClient.Builder webClientBuilder) {
 		return new DefaultHttpGraphQlClientBuilder(webClientBuilder);
@@ -67,6 +70,7 @@ public interface HttpGraphQlClient extends WebGraphQlClient {
 
 	/**
 	 * Builder for the GraphQL over HTTP client.
+	 * @param <B> the builder type
 	 */
 	interface Builder<B extends Builder<B>> extends WebGraphQlClient.Builder<B> {
 
@@ -74,6 +78,7 @@ public interface HttpGraphQlClient extends WebGraphQlClient {
 		 * Customize the {@code WebClient} to use.
 		 * <p>Note that some properties of {@code WebClient.Builder} like the
 		 * base URL, headers, and codecs can be customized through this builder.
+		 * @param webClient the function for customizing the {@code WebClient.Builder} that's used to build the HTTP client
 		 * @see #url(String)
 		 * @see #header(String, String...)
 		 * @see #codecConfigurer(Consumer)

spring-graphql/src/main/java/org/springframework/graphql/client/HttpGraphQlTransport.java

@@ -39,15 +39,14 @@ import org.springframework.web.reactive.function.client.WebClient;
  *
  * @author Rossen Stoyanchev
  * @author Brian Clozel
- * @since 1.0.0
  */
 final class HttpGraphQlTransport implements GraphQlTransport {
 
 	private static final ParameterizedTypeReference<Map<String, Object>> MAP_TYPE =
-			new ParameterizedTypeReference<Map<String, Object>>() {};
+			new ParameterizedTypeReference<Map<String, Object>>() { };
 
 	private static final ParameterizedTypeReference<ServerSentEvent<Map<String, Object>>> SSE_TYPE =
-			new ParameterizedTypeReference<ServerSentEvent<Map<String, Object>>>() {};
+			new ParameterizedTypeReference<ServerSentEvent<Map<String, Object>>>() { };
 
 	// To be removed in favor of Framework's MediaType.APPLICATION_GRAPHQL_RESPONSE
 	private static final MediaType APPLICATION_GRAPHQL_RESPONSE =
@@ -69,7 +68,7 @@ final class HttpGraphQlTransport implements GraphQlTransport {
 		HttpHeaders headers = new HttpHeaders();
 		webClient.mutate().defaultHeaders(headers::putAll);
 		MediaType contentType = headers.getContentType();
-		return (contentType != null ? contentType : MediaType.APPLICATION_JSON);
+		return (contentType != null) ? contentType : MediaType.APPLICATION_JSON;
 	}
 
 
@@ -80,7 +79,7 @@ final class HttpGraphQlTransport implements GraphQlTransport {
 				.contentType(this.contentType)
 				.accept(MediaType.APPLICATION_JSON, APPLICATION_GRAPHQL_RESPONSE, MediaType.APPLICATION_GRAPHQL)
 				.bodyValue(request.toMap())
-				.attributes(attributes -> {
+				.attributes((attributes) -> {
 					if (request instanceof ClientGraphQlRequest clientRequest) {
 						attributes.putAll(clientRequest.getAttributes());
 					}
@@ -96,15 +95,15 @@ final class HttpGraphQlTransport implements GraphQlTransport {
 				.contentType(this.contentType)
 				.accept(MediaType.TEXT_EVENT_STREAM)
 				.bodyValue(request.toMap())
-				.attributes(attributes -> {
+				.attributes((attributes) -> {
 					if (request instanceof ClientGraphQlRequest clientRequest) {
 						attributes.putAll(clientRequest.getAttributes());
 					}
 				})
 				.retrieve()
 				.bodyToFlux(SSE_TYPE)
-				.takeWhile(event -> "next".equals(event.event()))
-				.map(event -> new ResponseMapGraphQlResponse(event.data()));
+				.takeWhile((event) -> "next".equals(event.event()))
+				.map((event) -> new ResponseMapGraphQlResponse(event.data()));
 	}
 
 }

spring-graphql/src/main/java/org/springframework/graphql/client/HttpMessageConverterDelegate.java

@@ -54,14 +54,17 @@ import org.springframework.util.MimeType;
  * for JSON and adapt it to {@link Encoder} and {@link Decoder}.
  *
  * @author Rossen Stoyanchev
- * @since 1.3
  */
 final class HttpMessageConverterDelegate {
 
+	private HttpMessageConverterDelegate() {
+
+	}
+
 	@SuppressWarnings("unchecked")
 	static HttpMessageConverter<Object> findJsonConverter(List<HttpMessageConverter<?>> converters) {
 		return (HttpMessageConverter<Object>) converters.stream()
-				.filter(converter -> converter.canRead(Map.class, MediaType.APPLICATION_JSON))
+				.filter((converter) -> converter.canRead(Map.class, MediaType.APPLICATION_JSON))
 				.findFirst()
 				.orElseThrow(() -> new IllegalArgumentException("No JSON HttpMessageConverter"));
 	}
@@ -79,14 +82,14 @@ final class HttpMessageConverterDelegate {
 		if (mimeType instanceof MediaType mediaType) {
 			return mediaType;
 		}
-		return (mimeType != null ? new MediaType(mimeType) : null);
+		return (mimeType != null) ? new MediaType(mimeType) : null;
 	}
 
 
 	/**
 	 * Partial Encoder implementation to encode a single value through an HttpMessageConverter.
 	 */
-	private static class HttpMessageConverterEncoder implements Encoder<Object> {
+	private static final class HttpMessageConverterEncoder implements Encoder<Object> {
 
 		private final HttpMessageConverter<Object> converter;
 
@@ -140,7 +143,7 @@ final class HttpMessageConverterDelegate {
 	/**
 	 * Partial Decoder implementation to decode a single buffer through an HttpMessageConverter.
 	 */
-	private static class HttpMessageConverterDecoder implements Decoder<Object> {
+	private static final class HttpMessageConverterDecoder implements Decoder<Object> {
 
 		private final HttpMessageConverter<Object> converter;
 
@@ -196,7 +199,7 @@ final class HttpMessageConverterDelegate {
 	}
 
 
-	private static class HttpInputMessageAdapter extends ByteArrayInputStream implements HttpInputMessage {
+	private static final class HttpInputMessageAdapter extends ByteArrayInputStream implements HttpInputMessage {
 
 		HttpInputMessageAdapter(DataBuffer buffer) {
 			super(toBytes(buffer));
@@ -222,7 +225,7 @@ final class HttpMessageConverterDelegate {
 	}
 
 
-	private static class HttpOutputMessageAdapter extends ByteArrayOutputStream implements HttpOutputMessage {
+	private static final class HttpOutputMessageAdapter extends ByteArrayOutputStream implements HttpOutputMessage {
 
 		private static final HttpHeaders noOpHeaders = new HttpHeaders();
 

spring-graphql/src/main/java/org/springframework/graphql/client/HttpSyncGraphQlClient.java

@@ -42,6 +42,7 @@ public interface HttpSyncGraphQlClient extends GraphQlClient {
 
 	/**
 	 * Create an {@link HttpSyncGraphQlClient} that uses the given {@link RestClient}.
+	 * @param client the {@code RestClient} to use for HTTP requests
 	 */
 	static HttpSyncGraphQlClient create(RestClient client) {
 		return builder(client.mutate()).build();
@@ -57,6 +58,7 @@ public interface HttpSyncGraphQlClient extends GraphQlClient {
 	/**
 	 * Variant of {@link #builder()} with a pre-configured {@code RestClient}
 	 * to mutate and customize further through the returned builder.
+	 * @param client the {@code RestClient} to use for HTTP requests
 	 */
 	static Builder<?> builder(RestClient client) {
 		return builder(client.mutate());
@@ -65,6 +67,7 @@ public interface HttpSyncGraphQlClient extends GraphQlClient {
 	/**
 	 * Variant of {@link #builder()} with a pre-configured {@code RestClient}
 	 * to mutate and customize further through the returned builder.
+	 * @param builder the {@code RestClient} builder to use for HTTP requests
 	 */
 	static Builder<?> builder(RestClient.Builder builder) {
 		return new DefaultSyncHttpGraphQlClientBuilder(builder);
@@ -73,6 +76,7 @@ public interface HttpSyncGraphQlClient extends GraphQlClient {
 
 	/**
 	 * Builder for the GraphQL over HTTP client with a blocking execution chain.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends GraphQlClient.SyncBuilder<B> {
 
@@ -115,6 +119,7 @@ public interface HttpSyncGraphQlClient extends GraphQlClient {
 		 * Customize the underlying {@code RestClient}.
 		 * <p>Note that some properties of {@code RestClient.Builder} like the base URL,
 		 * headers, and message converters can be customized through this builder.
+		 * @param builderConsumer a consumer that customizes the {@code RestClient}.
 		 * @see #url(String)
 		 * @see #header(String, String...)
 		 * @see #messageConverters(Consumer)

spring-graphql/src/main/java/org/springframework/graphql/client/HttpSyncGraphQlTransport.java

@@ -32,11 +32,10 @@ import org.springframework.web.client.RestClient;
  * Transport for GraphQL over HTTP requests executed with {@link RestClient}.
  *
  * @author Rossen Stoyanchev
- * @since 1.3
  */
 final class HttpSyncGraphQlTransport implements SyncGraphQlTransport {
 
-	private static final ParameterizedTypeReference<Map<String, Object>> MAP_TYPE = new ParameterizedTypeReference<>() {};
+	private static final ParameterizedTypeReference<Map<String, Object>> MAP_TYPE = new ParameterizedTypeReference<>() { };
 
 
 	private final RestClient restClient;
@@ -54,7 +53,7 @@ final class HttpSyncGraphQlTransport implements SyncGraphQlTransport {
 		HttpHeaders headers = new HttpHeaders();
 		webClient.mutate().defaultHeaders(headers::putAll);
 		MediaType contentType = headers.getContentType();
-		return (contentType != null ? contentType : MediaType.APPLICATION_JSON);
+		return (contentType != null) ? contentType : MediaType.APPLICATION_JSON;
 	}
 
 
@@ -68,7 +67,7 @@ final class HttpSyncGraphQlTransport implements SyncGraphQlTransport {
 				.retrieve()
 				.body(MAP_TYPE);
 
-		return new ResponseMapGraphQlResponse(body != null ? body : Collections.emptyMap());
+		return new ResponseMapGraphQlResponse((body != null) ? body : Collections.emptyMap());
 	}
 
 }

spring-graphql/src/main/java/org/springframework/graphql/client/RSocketGraphQlClient.java

@@ -70,6 +70,7 @@ public interface RSocketGraphQlClient extends GraphQlClient {
 
 	/**
 	 * Start with a given {@link #builder()}.
+	 * @param requesterBuilder the existing request builder
 	 */
 	static Builder<?> builder(RSocketRequester.Builder requesterBuilder) {
 		return new DefaultRSocketGraphQlClientBuilder(requesterBuilder);
@@ -78,6 +79,7 @@ public interface RSocketGraphQlClient extends GraphQlClient {
 
 	/**
 	 * Builder for the GraphQL over HTTP client.
+	 * @param <B> the builder type
 	 */
 	interface Builder<B extends Builder<B>> extends GraphQlClient.Builder<B> {
 
@@ -146,11 +148,12 @@ public interface RSocketGraphQlClient extends GraphQlClient {
 		 * <p>Note that some properties of {@code RSocketRequester.Builder} like the
 		 * data MimeType, and the underlying RSocket transport can be customized
 		 * through this builder.
+		 * @param requester the requester to be customized
+		 * @return the same builder instance
 		 * @see #dataMimeType(MimeType)
 		 * @see #tcp(String, int)
 		 * @see #webSocket(URI)
 		 * @see #clientTransport(ClientTransport)
-		 * @return the same builder instance
 		 */
 		B rsocketRequester(Consumer<RSocketRequester.Builder> requester);
 

spring-graphql/src/main/java/org/springframework/graphql/client/RSocketGraphQlTransport.java

@@ -45,12 +45,11 @@ import org.springframework.util.Assert;
  * metadata extension.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 final class RSocketGraphQlTransport implements GraphQlTransport {
 
 	private static final ParameterizedTypeReference<Map<String, Object>> MAP_TYPE =
-			new ParameterizedTypeReference<Map<String, Object>>() {};
+			new ParameterizedTypeReference<Map<String, Object>>() { };
 
 	private static final ResolvableType LIST_TYPE = ResolvableType.forClass(List.class);
 
@@ -83,7 +82,7 @@ final class RSocketGraphQlTransport implements GraphQlTransport {
 	public Flux<GraphQlResponse> executeSubscription(GraphQlRequest request) {
 		return this.rsocketRequester.route(this.route).data(request.toMap())
 				.retrieveFlux(MAP_TYPE)
-				.onErrorResume(RejectedException.class, ex -> Flux.error(decodeErrors(request, ex)))
+				.onErrorResume(RejectedException.class, (ex) -> Flux.error(decodeErrors(request, ex)))
 				.map(ResponseMapGraphQlResponse::new);
 	}
 

spring-graphql/src/main/java/org/springframework/graphql/client/ResponseMapGraphQlResponse.java

@@ -36,7 +36,6 @@ import org.springframework.util.ObjectUtils;
  * {@link GraphQlResponse} that wraps a deserialized the GraphQL response map.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  */
 class ResponseMapGraphQlResponse extends AbstractGraphQlResponse {
 
@@ -60,7 +59,7 @@ class ResponseMapGraphQlResponse extends AbstractGraphQlResponse {
 	@SuppressWarnings("unchecked")
 	private static List<ResponseError> wrapErrors(Map<String, Object> map) {
 		List<Map<String, Object>> errors = (List<Map<String, Object>>) map.get("errors");
-		errors = (errors != null ? errors : Collections.emptyList());
+		errors = (errors != null) ? errors : Collections.emptyList();
 		return errors.stream().map(MapResponseError::new).collect(Collectors.toList());
 	}
 
@@ -134,7 +133,7 @@ class ResponseMapGraphQlResponse extends AbstractGraphQlResponse {
 				return Collections.emptyList();
 			}
 			return locations.stream()
-					.map(m -> new SourceLocation(getInt(m, "line"), getInt(m, "column"), (String) m.get("sourceName")))
+					.map((m) -> new SourceLocation(getInt(m, "line"), getInt(m, "column"), (String) m.get("sourceName")))
 					.collect(Collectors.toList());
 		}
 
@@ -155,7 +154,7 @@ class ResponseMapGraphQlResponse extends AbstractGraphQlResponse {
 				return "";
 			}
 			return path.stream().reduce("",
-					(s, o) -> s + (o instanceof Integer ? "[" + o + "]" : (s.isEmpty() ? o : "." + o)),
+					(s, o) -> s + ((o instanceof Integer) ? "[" + o + "]" : (s.isEmpty() ? o : "." + o)),
 					(s, s2) -> null);
 		}
 
@@ -163,7 +162,7 @@ class ResponseMapGraphQlResponse extends AbstractGraphQlResponse {
 		@Override
 		@Nullable
 		public String getMessage() {
-			return (String) errorMap.get("message");
+			return (String) this.errorMap.get("message");
 		}
 
 		@Override

spring-graphql/src/main/java/org/springframework/graphql/client/SubscriptionErrorException.java

@@ -38,6 +38,8 @@ public class SubscriptionErrorException extends GraphQlTransportException {
 	/**
 	 * Constructor with the request details and the errors listed in the payload
 	 * of the {@code "errors"} message.
+	 * @param request the request details
+	 * @param errors the errors listed in the payload
 	 */
 	public SubscriptionErrorException(GraphQlRequest request, List<ResponseError> errors) {
 		super("GraphQL subscription completed with an \"error\" message, " +

spring-graphql/src/main/java/org/springframework/graphql/client/SyncGraphQlClientInterceptor.java

@@ -50,7 +50,7 @@ public interface SyncGraphQlClientInterceptor {
 			@Override
 			public ClientGraphQlResponse intercept(ClientGraphQlRequest request, Chain chain) {
 				return SyncGraphQlClientInterceptor.this.intercept(
-						request, nextRequest -> interceptor.intercept(nextRequest, chain));
+						request, (nextRequest) -> interceptor.intercept(nextRequest, chain));
 			}
 		};
 	}

spring-graphql/src/main/java/org/springframework/graphql/client/WebGraphQlClient.java

@@ -39,6 +39,7 @@ public interface WebGraphQlClient extends GraphQlClient {
 
 	/**
 	 * Base builder for GraphQL clients over a Web transport.
+	 * @param <B> the type of builder
 	 */
 	interface Builder<B extends Builder<B>> extends GraphQlClient.Builder<B> {
 
@@ -72,6 +73,7 @@ public interface WebGraphQlClient extends GraphQlClient {
 		 * Configure JSON encoders and decoders for use in the
 		 * {@link org.springframework.graphql.GraphQlResponse} to convert response
 		 * data to higher level objects.
+		 * @param codecsConsumer a callback that customizes the configured codecs
 		 */
 		B codecConfigurer(Consumer<CodecConfigurer> codecsConsumer);
 

spring-graphql/src/main/java/org/springframework/graphql/client/WebSocketDisconnectedException.java

@@ -35,6 +35,9 @@ public class WebSocketDisconnectedException extends GraphQlTransportException {
 	/**
 	 * Constructor with an explanation about the closure, along with the request
 	 * details and the status used to close the WebSocket session.
+	 * @param closeStatusMessage the message received when the connection was closed
+	 * @param request the ongoing request when the connection was closed
+	 * @param status the received close status
 	 */
 	public WebSocketDisconnectedException(String closeStatusMessage, GraphQlRequest request, CloseStatus status) {
 		super(closeStatusMessage, null, request);

spring-graphql/src/main/java/org/springframework/graphql/client/WebSocketGraphQlClient.java

@@ -85,6 +85,7 @@ public interface WebSocketGraphQlClient extends WebGraphQlClient {
 
 	/**
 	 * Builder for a GraphQL over WebSocket client.
+	 * @param <B> the builder type
 	 */
 	interface Builder<B extends Builder<B>> extends WebGraphQlClient.Builder<B> {
 

spring-graphql/src/main/java/org/springframework/graphql/client/WebSocketGraphQlTransport.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.client;
 
 import java.net.URI;
@@ -50,7 +51,6 @@ import org.springframework.web.reactive.socket.client.WebSocketClient;
  * {@link GraphQlTransport} for GraphQL over WebSocket via {@link WebSocketClient}.
  *
  * @author Rossen Stoyanchev
- * @since 1.0.0
  * @see <a href="https://github.com/enisdenjo/graphql-ws/blob/master/PROTOCOL.md">GraphQL over WebSocket protocol</a>
  */
 final class WebSocketGraphQlTransport implements GraphQlTransport {
@@ -78,7 +78,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		Assert.notNull(interceptor, "WebSocketGraphQlClientInterceptor is required");
 
 		this.url = url;
-		this.headers.putAll(headers != null ? headers : HttpHeaders.EMPTY);
+		this.headers.putAll((headers != null) ? headers : HttpHeaders.EMPTY);
 		this.webSocketClient = client;
 
 		this.graphQlSessionHandler = new GraphQlSessionHandler(codecConfigurer, interceptor);
@@ -100,7 +100,9 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 			Mono<GraphQlSession> sessionMono = handler.getGraphQlSession();
 
 			client.execute(uri, headers, handler)
-					.subscribe(aVoid -> {},
+					.subscribe((aVoid) -> {
+
+							},
 							handler::handleWebSocketSessionError,
 							handler::handleWebSocketSessionClosed);
 
@@ -109,19 +111,19 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 	}
 
 
-	public URI getUrl() {
+	URI getUrl() {
 		return this.url;
 	}
 
-	public HttpHeaders getHeaders() {
+	HttpHeaders getHeaders() {
 		return this.headers;
 	}
 
-	public WebSocketClient getWebSocketClient() {
+	WebSocketClient getWebSocketClient() {
 		return this.webSocketClient;
 	}
 
-	public CodecConfigurer getCodecConfigurer() {
+	CodecConfigurer getCodecConfigurer() {
 		return this.graphQlSessionHandler.getCodecConfigurer();
 	}
 
@@ -132,7 +134,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 	 * @return {@code Mono} that completes when the WebSocket is connected and
 	 * ready to begin sending GraphQL requests
 	 */
-	public Mono<Void> start() {
+	Mono<Void> start() {
 		this.graphQlSessionHandler.setStopped(false);
 		return this.graphQlSessionMono.then();
 	}
@@ -145,19 +147,19 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 	 * call {@link #start()} to allow requests again.
 	 * @return {@code Mono} that completes when the underlying session is closed
 	 */
-	public Mono<Void> stop() {
+	Mono<Void> stop() {
 		this.graphQlSessionHandler.setStopped(true);
-		return this.graphQlSessionMono.flatMap(GraphQlSession::close).onErrorResume(ex -> Mono.empty());
+		return this.graphQlSessionMono.flatMap(GraphQlSession::close).onErrorResume((ex) -> Mono.empty());
 	}
 
 	@Override
 	public Mono<GraphQlResponse> execute(GraphQlRequest request) {
-		return this.graphQlSessionMono.flatMap(session -> session.execute(request));
+		return this.graphQlSessionMono.flatMap((session) -> session.execute(request));
 	}
 
 	@Override
 	public Flux<GraphQlResponse> executeSubscription(GraphQlRequest request) {
-		return this.graphQlSessionMono.flatMapMany(session -> session.executeSubscription(request));
+		return this.graphQlSessionMono.flatMapMany((session) -> session.executeSubscription(request));
 	}
 
 
@@ -189,7 +191,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		}
 
 
-		public CodecConfigurer getCodecConfigurer() {
+		CodecConfigurer getCodecConfigurer() {
 			return this.codecDelegate.getCodecConfigurer();
 		}
 
@@ -205,7 +207,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		 * the "connection_init" and "connection_ack" messages are exchanged or
 		 * returns an error if it fails for any reason.
 		 */
-		public Mono<GraphQlSession> getGraphQlSession() {
+		Mono<GraphQlSession> getGraphQlSession() {
 			return this.graphQlSessionSink.asMono();
 		}
 
@@ -213,14 +215,14 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		 * When the handler is marked "stopped", i.e. set to {@code true}, new
 		 * requests are rejected. When set to {@code true} they are allowed.
 		 */
-		public void setStopped(boolean stopped) {
+		void setStopped(boolean stopped) {
 			this.stopped.set(stopped);
 		}
 
 		/**
 		 * Whether the handler is marked {@link #setStopped(boolean) "stopped"}.
 		 */
-		public boolean isStopped() {
+		boolean isStopped() {
 			return this.stopped.get();
 		}
 
@@ -241,10 +243,10 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 
 			Mono<Void> sendCompletion =
 					session.send(connectionInitMono.concatWith(graphQlSession.getRequestFlux())
-							.map(message -> this.codecDelegate.encode(session, message)));
+							.map((message) -> this.codecDelegate.encode(session, message)));
 
 			Mono<Void> receiveCompletion = session.receive()
-					.flatMap(webSocketMessage -> {
+					.flatMap((webSocketMessage) -> {
 						if (sessionNotInitialized()) {
 							try {
 								GraphQlWebSocketMessage message = this.codecDelegate.decode(webSocketMessage);
@@ -301,14 +303,14 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		private void registerCloseStatusHandling(GraphQlSession graphQlSession, WebSocketSession session) {
 			session.closeStatus()
 					.defaultIfEmpty(CloseStatus.NO_STATUS_CODE)
-					.doOnNext(closeStatus -> {
+					.doOnNext((closeStatus) -> {
 						String closeStatusMessage = initCloseStatusMessage(closeStatus, null, graphQlSession);
 						if (logger.isDebugEnabled()) {
 							logger.debug(closeStatusMessage);
 						}
 						graphQlSession.terminateRequests(closeStatusMessage, closeStatus);
 					})
-					.doOnError(cause -> {
+					.doOnError((cause) -> {
 						CloseStatus closeStatus = CloseStatus.NO_STATUS_CODE;
 						String closeStatusMessage = initCloseStatusMessage(closeStatus, cause, graphQlSession);
 						if (logger.isErrorEnabled()) {
@@ -347,7 +349,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		 * with an error. The error is routed to subscribers of
 		 * {@link #getGraphQlSession()} which is necessary for connection issues.
 		 */
-		public void handleWebSocketSessionError(Throwable ex) {
+		void handleWebSocketSessionError(Throwable ex) {
 
 			if (logger.isDebugEnabled()) {
 				logger.debug("Session handling error: " + ex.getMessage(), ex);
@@ -364,7 +366,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		 * This must be called from code that calls the {@code WebSocketClient}
 		 * when execution completes.
 		 */
-		public void handleWebSocketSessionClosed() {
+		void handleWebSocketSessionClosed() {
 			this.graphQlSessionSink = Sinks.unsafe().one();
 		}
 
@@ -396,16 +398,16 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		/**
 		 * Return the {@code Flux} of GraphQL requests to send as WebSocket messages.
 		 */
-		public Flux<GraphQlWebSocketMessage> getRequestFlux() {
+		Flux<GraphQlWebSocketMessage> getRequestFlux() {
 			return this.requestSink.getRequestFlux();
 		}
 
 
 		// Outbound messages
 
-		public Mono<GraphQlResponse> execute(GraphQlRequest request) {
+		Mono<GraphQlResponse> execute(GraphQlRequest request) {
 			String id = String.valueOf(this.requestIndex.incrementAndGet());
-			return Mono.<GraphQlResponse>create(sink -> {
+			return Mono.<GraphQlResponse>create((sink) -> {
 				SingleResponseRequestState state = new SingleResponseRequestState(request, sink);
 				this.requestStateMap.put(id, state);
 				try {
@@ -419,9 +421,9 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 			}).doOnCancel(() -> this.requestStateMap.remove(id));
 		}
 
-		public Flux<GraphQlResponse> executeSubscription(GraphQlRequest request) {
+		Flux<GraphQlResponse> executeSubscription(GraphQlRequest request) {
 			String id = String.valueOf(this.requestIndex.incrementAndGet());
-			return Flux.<GraphQlResponse>create(sink -> {
+			return Flux.<GraphQlResponse>create((sink) -> {
 				SubscriptionRequestState state = new SubscriptionRequestState(request, sink);
 				this.requestStateMap.put(id, state);
 				try {
@@ -452,7 +454,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 			}
 		}
 
-		public void sendPong(@Nullable Map<String, Object> payload) {
+		void sendPong(@Nullable Map<String, Object> payload) {
 			GraphQlWebSocketMessage message = GraphQlWebSocketMessage.pong(payload);
 			this.requestSink.sendRequest(message);
 		}
@@ -463,7 +465,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		/**
 		 * Handle a "next" message and route to its recipient.
 		 */
-		public void handleNext(GraphQlWebSocketMessage message) {
+		void handleNext(GraphQlWebSocketMessage message) {
 			String id = message.getId();
 			RequestState requestState = this.requestStateMap.get(id);
 			if (requestState == null) {
@@ -486,7 +488,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		 * Handle an "error" message, turning it into an {@link GraphQlResponse}
 		 * for single responses, or signaling an error for streams.
 		 */
-		public void handleError(GraphQlWebSocketMessage message) {
+		void handleError(GraphQlWebSocketMessage message) {
 			String id = message.getId();
 			RequestState requestState = this.requestStateMap.remove(id);
 			if (requestState == null) {
@@ -512,7 +514,7 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		/**
 		 * Handle a "complete" message.
 		 */
-		public void handleComplete(GraphQlWebSocketMessage message) {
+		void handleComplete(GraphQlWebSocketMessage message) {
 			String id = message.getId();
 			RequestState requestState = this.requestStateMap.remove(id);
 			if (requestState == null) {
@@ -528,22 +530,22 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 		 * Return a {@code Mono} that completes when the connection is closed
 		 * for any reason.
 		 */
-		public Mono<Void> notifyWhenClosed() {
+		Mono<Void> notifyWhenClosed() {
 			return this.connection.notifyWhenClosed();
 		}
 
 		/**
 		 * Close the underlying connection.
 		 */
-		public Mono<Void> close() {
+		Mono<Void> close() {
 			return this.connection.close(CloseStatus.GOING_AWAY);
 		}
 
 		/**
 		 * Terminate and clean all in-progress requests with the given error.
 		 */
-		public void terminateRequests(String message, CloseStatus status) {
-			this.requestStateMap.values().forEach(info -> info.emitDisconnectError(message, status));
+		void terminateRequests(String message, CloseStatus status) {
+			this.requestStateMap.values().forEach((info) -> info.emitDisconnectError(message, status));
 			this.requestStateMap.clear();
 		}
 
@@ -595,21 +597,21 @@ final class WebSocketGraphQlTransport implements GraphQlTransport {
 	/**
 	 * Holds the request {@code Flux} and associated {@link FluxSink}.
 	 */
-	private static class RequestSink {
+	private static final class RequestSink {
 
 		@Nullable
 		private FluxSink<GraphQlWebSocketMessage> requestSink;
 
-		private final Flux<GraphQlWebSocketMessage> requestFlux = Flux.create(sink -> {
+		private final Flux<GraphQlWebSocketMessage> requestFlux = Flux.create((sink) -> {
 			Assert.state(this.requestSink == null, "Expected single subscriber only for outbound messages");
 			this.requestSink = sink;
 		});
 
-		public Flux<GraphQlWebSocketMessage> getRequestFlux() {
+		Flux<GraphQlWebSocketMessage> getRequestFlux() {
 			return this.requestFlux;
 		}
 
-		public void sendRequest(GraphQlWebSocketMessage message) {
+		void sendRequest(GraphQlWebSocketMessage message) {
 			Assert.state(this.requestSink != null, "Unexpected request before Flux is subscribed to");
 			this.requestSink.next(message);
 		}

spring-graphql/src/main/java/org/springframework/graphql/data/ArgumentValue.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data;
 
 
@@ -39,8 +40,8 @@ import org.springframework.util.ObjectUtils;
  * object.
  * </ul>
  *
- * @author Rossen Stoyanchev
  * @param <T> the type of value contained
+ * @author Rossen Stoyanchev
  * @since 1.1.0
  * @see <a href="http://spec.graphql.org/October2021/#sec-Non-Null.Nullable-vs-Optional">Nullable vs Optional</a>
  */
@@ -115,6 +116,7 @@ public final class ArgumentValue<T> {
 	/**
 	 * Static factory method for an argument value that was provided, even if
 	 * it was set to {@literal "null}.
+	 * @param <T> the type of value
 	 * @param value the value to hold in the instance
 	 */
 	public static <T> ArgumentValue<T> ofNullable(@Nullable T value) {
@@ -123,6 +125,7 @@ public final class ArgumentValue<T> {
 
 	/**
 	 * Static factory method for an argument value that was omitted.
+	 * @param <T> the type of value
 	 */
 	@SuppressWarnings("unchecked")
 	public static <T> ArgumentValue<T> omitted() {

spring-graphql/src/main/java/org/springframework/graphql/data/GraphQlArgumentBinder.java

@@ -139,7 +139,7 @@ public class GraphQlArgumentBinder {
 			DataFetchingEnvironment environment, @Nullable String name, ResolvableType targetType)
 			throws BindException {
 
-		Object rawValue = (name != null ? environment.getArgument(name) : environment.getArguments());
+		Object rawValue = (name != null) ? environment.getArgument(name) : environment.getArguments();
 		boolean isOmitted = (name != null && !environment.getArguments().containsKey(name));
 
 		return bind(name, rawValue, isOmitted, targetType);
@@ -148,6 +148,11 @@ public class GraphQlArgumentBinder {
 	/**
 	 * Variant of {@link #bind(DataFetchingEnvironment, String, ResolvableType)}
 	 * with a pre-extracted raw value to bind from.
+	 * @param name the name of an argument, or {@code null} to use the full map
+	 * @param rawValue the raw argument value (Collection, Map, or scalar)
+	 * @param isOmitted {@code true} if the argument was omitted from the input
+	 * and {@code false} if it was provided, but possibly {@code null}
+	 * @param targetType the type of Object to create
 	 * @since 1.3
 	 */
 	@Nullable
@@ -259,9 +264,9 @@ public class GraphQlArgumentBinder {
 
 		Constructor<?> constructor = BeanUtils.getResolvableConstructor(targetClass);
 
-		Object value = (constructor.getParameterCount() > 0 ?
+		Object value = (constructor.getParameterCount() > 0) ?
 				bindMapToObjectViaConstructor(rawMap, constructor, targetType, bindingResult) :
-				bindMapToObjectViaSetters(rawMap, constructor, targetType, bindingResult));
+				bindMapToObjectViaSetters(rawMap, constructor, targetType, bindingResult);
 
 		bindingResult.popNestedPath();
 
@@ -373,7 +378,7 @@ public class GraphQlArgumentBinder {
 		Object value = null;
 		try {
 			TypeConverter converter =
-					(this.typeConverter != null ? this.typeConverter : new SimpleTypeConverter());
+					(this.typeConverter != null) ? this.typeConverter : new SimpleTypeConverter();
 
 			value = converter.convertIfNecessary(
 					rawValue, (Class<?>) clazz, new TypeDescriptor(type, null, null));
@@ -398,9 +403,9 @@ public class GraphQlArgumentBinder {
 		}
 
 		private static String initObjectName(ResolvableType targetType) {
-			return (targetType.getSource() instanceof MethodParameter methodParameter ?
+			return (targetType.getSource() instanceof MethodParameter methodParameter) ?
 					Conventions.getVariableNameForParameter(methodParameter) :
-					ClassUtils.getShortNameAsProperty(targetType.resolve(Object.class)));
+					ClassUtils.getShortNameAsProperty(targetType.resolve(Object.class));
 		}
 
 		@Override
@@ -413,7 +418,7 @@ public class GraphQlArgumentBinder {
 			return null;
 		}
 
-		public void rejectArgumentValue(
+		void rejectArgumentValue(
 				String field, @Nullable Object rawValue, String code, String defaultMessage) {
 
 			addError(new FieldError(

spring-graphql/src/main/java/org/springframework/graphql/data/GraphQlRepository.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/federation/EntitiesDataFetcher.java

@@ -44,7 +44,6 @@ import org.springframework.lang.Nullable;
  * {@link EntityHandlerMethod}s.
  *
  * @author Rossen Stoyanchev
- * @since 1.3
  * @see com.apollographql.federation.graphqljava.SchemaTransformer#fetchEntities(DataFetcher)
  */
 final class EntitiesDataFetcher implements DataFetcher<Mono<DataFetcherResult<List<Object>>>> {
@@ -54,7 +53,7 @@ final class EntitiesDataFetcher implements DataFetcher<Mono<DataFetcherResult<Li
 	private final HandlerDataFetcherExceptionResolver exceptionResolver;
 
 
-	public EntitiesDataFetcher(
+	EntitiesDataFetcher(
 			Map<String, EntityHandlerMethod> handlerMethods, HandlerDataFetcherExceptionResolver resolver) {
 
 		this.handlerMethods = new LinkedHashMap<>(handlerMethods);
@@ -90,15 +89,15 @@ final class EntitiesDataFetcher implements DataFetcher<Mono<DataFetcherResult<Li
 
 		return handlerMethod.getEntity(env, map, index)
 				.switchIfEmpty(Mono.error(new RepresentationNotResolvedException(map, handlerMethod)))
-				.onErrorResume(ex -> resolveException(ex, env, handlerMethod, index));
+				.onErrorResume((ex) -> resolveException(ex, env, handlerMethod, index));
 	}
 
 	private Mono<Object> resolveException(
 			Throwable ex, DataFetchingEnvironment env, @Nullable EntityHandlerMethod handlerMethod, int index) {
 
-		Throwable theEx = (ex instanceof CompletionException ? ex.getCause() : ex);
+		Throwable theEx = (ex instanceof CompletionException) ? ex.getCause() : ex;
 		DataFetchingEnvironment theEnv = new EntityDataFetchingEnvironment(env, index);
-		Object handler = (handlerMethod != null ? handlerMethod.getBean() : null);
+		Object handler = (handlerMethod != null) ? handlerMethod.getBean() : null;
 
 		return this.exceptionResolver.resolveException(theEx, theEnv, handler)
 				.map(ErrorContainer::new)
@@ -108,8 +107,8 @@ final class EntitiesDataFetcher implements DataFetcher<Mono<DataFetcherResult<Li
 
 	private ErrorContainer createDefaultError(Throwable ex, DataFetchingEnvironment env) {
 
-		ErrorType errorType = (ex instanceof RepresentationException representationEx ?
-				representationEx.getErrorType() : ErrorType.INTERNAL_ERROR);
+		ErrorType errorType = (ex instanceof RepresentationException representationEx) ?
+				representationEx.getErrorType() : ErrorType.INTERNAL_ERROR;
 
 		return new ErrorContainer(GraphqlErrorBuilder.newError(env)
 				.errorType(errorType)
@@ -134,7 +133,7 @@ final class EntitiesDataFetcher implements DataFetcher<Mono<DataFetcherResult<Li
 
 		private final ExecutionStepInfo executionStepInfo;
 
-		public EntityDataFetchingEnvironment(DataFetchingEnvironment env, int index) {
+		EntityDataFetchingEnvironment(DataFetchingEnvironment env, int index) {
 			super(env);
 			this.executionStepInfo = ExecutionStepInfo.newExecutionStepInfo(env.getExecutionStepInfo())
 					.path(env.getExecutionStepInfo().getPath().segment(index))

spring-graphql/src/main/java/org/springframework/graphql/data/federation/EntityArgumentMethodArgumentResolver.java

@@ -34,7 +34,6 @@ import org.springframework.validation.BindException;
  * the entity uniquely.
  *
  * @author Rossen Stoyanchev
- * @since 1.3
  */
 final class EntityArgumentMethodArgumentResolver extends ArgumentMethodArgumentResolver {
 
@@ -61,7 +60,7 @@ final class EntityArgumentMethodArgumentResolver extends ArgumentMethodArgumentR
 	/**
 	 * Wrap the environment in order to also expose the entity representation map.
 	 */
-	public static DataFetchingEnvironment wrap(DataFetchingEnvironment env, Map<String, Object> representation) {
+	static DataFetchingEnvironment wrap(DataFetchingEnvironment env, Map<String, Object> representation) {
 		return new EntityDataFetchingEnvironment(env, representation);
 	}
 
@@ -75,7 +74,7 @@ final class EntityArgumentMethodArgumentResolver extends ArgumentMethodArgumentR
 			this.representation = representation;
 		}
 
-		public Map<String, Object> getRepresentation() {
+		Map<String, Object> getRepresentation() {
 			return this.representation;
 		}
 	}

spring-graphql/src/main/java/org/springframework/graphql/data/federation/EntityHandlerMethod.java

@@ -32,11 +32,10 @@ import org.springframework.lang.Nullable;
  * Invokable controller method to fetch a federated entity.
  *
  * @author Rossen Stoyanchev
- * @since 1.3
  */
 final class EntityHandlerMethod extends DataFetcherHandlerMethodSupport {
 
-	public EntityHandlerMethod(
+	EntityHandlerMethod(
 			HandlerMethod handlerMethod, HandlerMethodArgumentResolverComposite resolvers,
 			@Nullable Executor executor) {
 
@@ -44,7 +43,7 @@ final class EntityHandlerMethod extends DataFetcherHandlerMethodSupport {
 	}
 
 
-	public Mono<Object> getEntity(
+	Mono<Object> getEntity(
 			DataFetchingEnvironment environment, Map<String, Object> representation, int index) {
 
 		Object[] args;

spring-graphql/src/main/java/org/springframework/graphql/data/federation/FederationSchemaFactory.java

@@ -75,6 +75,7 @@ public final class FederationSchemaFactory
 	/**
 	 * Configure a resolver that helps to map Java to entity schema type names.
 	 * <p>By default this is {@link ClassNameTypeResolver}.
+	 * @param typeResolver the custom type resolver to use
 	 * @see SchemaTransformer#resolveEntityType(TypeResolver)
 	 */
 	public void setTypeResolver(@Nullable TypeResolver typeResolver) {
@@ -86,7 +87,7 @@ public final class FederationSchemaFactory
 	public void afterPropertiesSet() {
 		super.afterPropertiesSet();
 
-		detectHandlerMethods().forEach(info ->
+		detectHandlerMethods().forEach((info) ->
 				this.handlerMethods.put(info.typeName(),
 						new EntityHandlerMethod(info.handlerMethod(), getArgumentResolvers(), getExecutor())));
 
@@ -149,6 +150,8 @@ public final class FederationSchemaFactory
 	 * Create {@link GraphQLSchema} via {@link SchemaTransformer}, setting up
 	 * the "_entities" {@link DataFetcher} and {@link TypeResolver} for federated types.
 	 * <p>Use this to supply a {@link SchemaResourceBuilder#schemaFactory(BiFunction) schemaFactory}.
+	 * @param registry the existing type definition registry
+	 * @param wiring the existing runtime wiring
 	 */
 	public GraphQLSchema createGraphQLSchema(TypeDefinitionRegistry registry, RuntimeWiring wiring) {
 		return createSchemaTransformer(registry, wiring).build();
@@ -157,6 +160,8 @@ public final class FederationSchemaFactory
 	/**
 	 * Alternative to {@link #createGraphQLSchema(TypeDefinitionRegistry, RuntimeWiring)}
 	 * that allows calling additional methods on {@link SchemaTransformer}.
+	 * @param registry the existing type definition registry
+	 * @param wiring the existing runtime wiring
 	 */
 	public SchemaTransformer createSchemaTransformer(TypeDefinitionRegistry registry, RuntimeWiring wiring) {
 		Assert.state(this.typeResolver != null, "afterPropertiesSet not called");

spring-graphql/src/main/java/org/springframework/graphql/data/federation/RepresentationException.java

@@ -55,7 +55,7 @@ public class RepresentationException extends RuntimeException {
 		super(msg);
 		this.representation = representation;
 		this.handlerMethod = hm;
-		this.errorType = (representation.get("__typename") == null ? ErrorType.BAD_REQUEST : ErrorType.INTERNAL_ERROR);
+		this.errorType = (representation.get("__typename") == null) ? ErrorType.BAD_REQUEST : ErrorType.INTERNAL_ERROR;
 	}
 
 

spring-graphql/src/main/java/org/springframework/graphql/data/method/HandlerMethod.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method;
 
 import java.lang.annotation.Annotation;
@@ -77,6 +78,8 @@ public class HandlerMethod {
 
 	/**
 	 * Constructor with a handler instance and a method.
+	 * @param bean the handler instance
+	 * @param method the handler method
 	 */
 	public HandlerMethod(Object bean, Method method) {
 		Assert.notNull(bean, "Bean is required");
@@ -94,6 +97,9 @@ public class HandlerMethod {
 	 * Constructor with a bean name for the handler along with a {@code BeanFactory}
 	 * to allow {@link #createWithResolvedBean() resolving} the handler instance
 	 * later.
+	 * @param beanName the bean name
+	 * @param beanFactory the bean factory to use for bean resolution
+	 * @param method the handler method
 	 */
 	public HandlerMethod(String beanName, BeanFactory beanFactory, Method method) {
 		Assert.hasText(beanName, "Bean name is required");
@@ -115,6 +121,7 @@ public class HandlerMethod {
 
 	/**
 	 * Copy constructor for use from subclasses that accept more arguments.
+	 * @param handlerMethod the handler method
 	 */
 	protected HandlerMethod(HandlerMethod handlerMethod) {
 		this(handlerMethod, handlerMethod.bean);
@@ -191,6 +198,7 @@ public class HandlerMethod {
 
 	/**
 	 * Return the actual return value type.
+	 * @param returnValue the return value instance, can be {@code null}
 	 */
 	public MethodParameter getReturnValueType(@Nullable Object returnValue) {
 		return new ReturnValueMethodParameter(returnValue);
@@ -208,6 +216,7 @@ public class HandlerMethod {
 	 * if no annotation can be found on the given method itself.
 	 * <p>Also supports <em>merged</em> composed annotations with attribute
 	 * overrides as of Spring Framework 4.3.
+	 * @param <A> the annotation type
 	 * @param annotationType the type of annotation to introspect the method for
 	 * @return the annotation, or {@code null} if none found
 	 * @see AnnotatedElementUtils#findMergedAnnotation
@@ -219,6 +228,7 @@ public class HandlerMethod {
 
 	/**
 	 * Return whether the parameter is declared with the given annotation type.
+	 * @param <A> the annotation type
 	 * @param annotationType the annotation type to look for
 	 * @see AnnotatedElementUtils#hasAnnotation
 	 */
@@ -331,6 +341,9 @@ public class HandlerMethod {
 	 * processing time may be a JDK dynamic proxy (lazy initialization, prototype
 	 * beans, and others). Endpoint classes that require proxying should prefer
 	 * class-based proxy mechanisms.
+	 * @param method the handler method
+	 * @param targetBean the bean instance
+	 * @param args the method arguments
 	 */
 	protected void assertTargetBean(Method method, Object targetBean, Object[] args) {
 		Class<?> methodDeclaringClass = method.getDeclaringClass();
@@ -347,9 +360,9 @@ public class HandlerMethod {
 	protected String formatInvokeError(String text, Object[] args) {
 
 		String formattedArgs = IntStream.range(0, args.length)
-				.mapToObj(i -> (args[i] != null ?
+				.mapToObj((i) -> (args[i] != null) ?
 						"[" + i + "] [type=" + args[i].getClass().getName() + "] [value=" + args[i] + "]" :
-						"[" + i + "] [null]"))
+						"[" + i + "] [null]")
 				.collect(Collectors.joining(",\n", " ", " "));
 
 		return text + "\n" +
@@ -401,21 +414,7 @@ public class HandlerMethod {
 						if (index < ifcAnns.length) {
 							Annotation[] paramAnns = ifcAnns[index];
 							if (paramAnns.length > 0) {
-								List<Annotation> merged = new ArrayList<>(anns.length + paramAnns.length);
-								merged.addAll(Arrays.asList(anns));
-								for (Annotation paramAnn : paramAnns) {
-									boolean existingType = false;
-									for (Annotation ann : anns) {
-										if (ann.annotationType() == paramAnn.annotationType()) {
-											existingType = true;
-											break;
-										}
-									}
-									if (!existingType) {
-										merged.add(adaptAnnotation(paramAnn));
-									}
-								}
-								anns = merged.toArray(new Annotation[0]);
+								anns = mergeAnnotations(anns, paramAnns);
 							}
 						}
 					}
@@ -424,6 +423,25 @@ public class HandlerMethod {
 			}
 			return anns;
 		}
+
+		private Annotation[] mergeAnnotations(Annotation[] anns, Annotation[] paramAnns) {
+			List<Annotation> merged = new ArrayList<>(anns.length + paramAnns.length);
+			merged.addAll(Arrays.asList(anns));
+			for (Annotation paramAnn : paramAnns) {
+				boolean existingType = false;
+				for (Annotation ann : anns) {
+					if (ann.annotationType() == paramAnn.annotationType()) {
+						existingType = true;
+						break;
+					}
+				}
+				if (!existingType) {
+					merged.add(adaptAnnotation(paramAnn));
+				}
+			}
+			anns = merged.toArray(new Annotation[0]);
+			return anns;
+		}
 	}
 
 
@@ -435,7 +453,7 @@ public class HandlerMethod {
 		@Nullable
 		private final Object returnValue;
 
-		public ReturnValueMethodParameter(@Nullable Object returnValue) {
+		ReturnValueMethodParameter(@Nullable Object returnValue) {
 			super(-1);
 			this.returnValue = returnValue;
 		}
@@ -447,7 +465,7 @@ public class HandlerMethod {
 
 		@Override
 		public Class<?> getParameterType() {
-			return (this.returnValue != null ? this.returnValue.getClass() : super.getParameterType());
+			return (this.returnValue != null) ? this.returnValue.getClass() : super.getParameterType();
 		}
 
 		@Override

spring-graphql/src/main/java/org/springframework/graphql/data/method/HandlerMethodArgumentResolver.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method;
 
 import graphql.schema.DataFetchingEnvironment;
@@ -35,20 +36,18 @@ public interface HandlerMethodArgumentResolver {
 
 	/**
 	 * Whether this resolver supports the given {@link MethodParameter}.
+	 * @param parameter the method parameter to check for support
 	 */
 	boolean supportsParameter(MethodParameter parameter);
 
 	/**
 	 * Resolve a method parameter to a value.
-	 *
 	 * @param parameter the method parameter to resolve. This parameter must
 	 * have previously checked via {@link #supportsParameter}.
 	 * @param environment the environment to use to resolve the value
-	 *
 	 * @return the resolved value, which may be {@code null} if not resolved;
 	 * the value may also be a {@link reactor.core.publisher.Mono} if it
 	 * requires asynchronous resolution.
-	 *
 	 * @throws Exception in case of errors with the preparation of argument values
 	 */
 	@Nullable

spring-graphql/src/main/java/org/springframework/graphql/data/method/HandlerMethodArgumentResolverComposite.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method;
 
 import java.util.ArrayList;
@@ -43,6 +44,7 @@ public class HandlerMethodArgumentResolverComposite implements HandlerMethodArgu
 
 	/**
 	 * Add the given {@link HandlerMethodArgumentResolver}.
+	 * @param resolver the argument resolver
 	 */
 	public void addResolver(HandlerMethodArgumentResolver resolver) {
 		this.argumentResolvers.add(resolver);
@@ -84,10 +86,11 @@ public class HandlerMethodArgumentResolverComposite implements HandlerMethodArgu
 	/**
 	 * Find a registered {@link HandlerMethodArgumentResolver} that supports
 	 * the given method parameter.
+	 * @param parameter the method parameter
 	 */
 	@Nullable
 	public HandlerMethodArgumentResolver getArgumentResolver(MethodParameter parameter) {
-		return this.argumentResolverCache.computeIfAbsent(parameter, p -> {
+		return this.argumentResolverCache.computeIfAbsent(parameter, (p) -> {
 			for (HandlerMethodArgumentResolver resolver : this.argumentResolvers) {
 				if (resolver.supportsParameter(parameter)) {
 					return resolver;
@@ -97,4 +100,4 @@ public class HandlerMethodArgumentResolverComposite implements HandlerMethodArgu
 		});
 	}
 
-}
+}

spring-graphql/src/main/java/org/springframework/graphql/data/method/InvocableHandlerMethodSupport.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method;
 
 import java.lang.reflect.InvocationTargetException;
@@ -25,7 +26,6 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
 
 import graphql.GraphQLContext;
-import io.micrometer.context.ContextSnapshot;
 import io.micrometer.context.ContextSnapshotFactory;
 import reactor.core.publisher.Mono;
 
@@ -72,6 +72,7 @@ public abstract class InvocableHandlerMethodSupport extends HandlerMethod {
 
 	/**
 	 * Invoke the handler method with the given argument values.
+	 * @param graphQLContext the GraphQL context for this data fetching operation
 	 * @param argValues the values to use to invoke the method
 	 * @return the value returned from the method or a {@code Mono<Throwable>}
 	 * if the invocation fails.
@@ -92,7 +93,7 @@ public abstract class InvocableHandlerMethodSupport extends HandlerMethod {
 		}
 		catch (IllegalArgumentException ex) {
 			assertTargetBean(method, getBean(), argValues);
-			String text = (ex.getMessage() != null ? ex.getMessage() : "Illegal argument");
+			String text = (ex.getMessage() != null) ? ex.getMessage() : "Illegal argument";
 			return Mono.error(new IllegalStateException(formatInvokeError(text, argValues), ex));
 		}
 		catch (InvocationTargetException ex) {
@@ -145,15 +146,16 @@ public abstract class InvocableHandlerMethodSupport extends HandlerMethod {
 	/**
 	 * Use this method to resolve the arguments asynchronously. This is only
 	 * useful when at least one of the values is a {@link Mono}
+	 * @param args the arguments to be resolved asynchronously
 	 */
 	@SuppressWarnings("unchecked")
 	protected Mono<Object[]> toArgsMono(Object[] args) {
 		List<Mono<Object>> monoList = new ArrayList<>();
 		for (Object arg : args) {
-			Mono<Object> argMono = (arg instanceof Mono ? (Mono<Object>) arg : Mono.justOrEmpty(arg));
+			Mono<Object> argMono = ((arg instanceof Mono) ? (Mono<Object>) arg : Mono.justOrEmpty(arg));
 			monoList.add(argMono.defaultIfEmpty(NO_VALUE));
 		}
-		return Mono.zip(monoList, values -> {
+		return Mono.zip(monoList, (values) -> {
 			for (int i = 0; i < values.length; i++) {
 				if (values[i] == NO_VALUE) {
 					values[i] = null;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/Argument.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/Arguments.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/BatchMapping.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/ContextValue.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/GraphQlExceptionHandler.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/LocalContextValue.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/MutationMapping.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/QueryMapping.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/SchemaMapping.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/SubscriptionMapping.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation;
 
 import java.lang.annotation.Documented;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import java.lang.annotation.Annotation;
@@ -105,13 +106,13 @@ public class AnnotatedControllerConfigurer
 
 	private static final ClassLoader classLoader = AnnotatedControllerConfigurer.class.getClassLoader();
 
-	private final static boolean springDataPresent = ClassUtils.isPresent(
+	private static final boolean springDataPresent = ClassUtils.isPresent(
 			"org.springframework.data.projection.SpelAwareProxyProjectionFactory", classLoader);
 
-	private final static boolean springSecurityPresent = ClassUtils.isPresent(
+	private static final boolean springSecurityPresent = ClassUtils.isPresent(
 			"org.springframework.security.core.context.SecurityContext", classLoader);
 
-	private final static boolean beanValidationPresent = ClassUtils.isPresent(
+	private static final boolean beanValidationPresent = ClassUtils.isPresent(
 			"jakarta.validation.executable.ExecutableValidator", classLoader);
 
 
@@ -125,7 +126,6 @@ public class AnnotatedControllerConfigurer
 	 * Add a {@link HandlerMethodArgumentResolver} for custom controller method
 	 * arguments. Such custom resolvers are ordered after built-in resolvers
 	 * except for {@link SourceMethodArgumentResolver}, which is always last.
-	 *
 	 * @param resolver the resolver to add.
 	 * @since 1.2.0
 	 */
@@ -228,7 +228,7 @@ public class AnnotatedControllerConfigurer
 
 	@Override
 	public void configure(RuntimeWiring.Builder runtimeWiringBuilder) {
-		detectHandlerMethods().forEach(info -> {
+		detectHandlerMethods().forEach((info) -> {
 			DataFetcher<?> dataFetcher;
 			if (!info.isBatchMapping()) {
 				dataFetcher = new SchemaMappingDataFetcher(
@@ -238,7 +238,7 @@ public class AnnotatedControllerConfigurer
 				dataFetcher = registerBatchLoader(info);
 			}
 			FieldCoordinates coordinates = info.getCoordinates();
-			runtimeWiringBuilder.type(coordinates.getTypeName(), typeBuilder ->
+			runtimeWiringBuilder.type(coordinates.getTypeName(), (typeBuilder) ->
 					typeBuilder.dataFetcher(coordinates.getFieldName(), dataFetcher));
 		});
 	}
@@ -322,7 +322,7 @@ public class AnnotatedControllerConfigurer
 		BatchLoaderRegistry registry = obtainApplicationContext().getBean(BatchLoaderRegistry.class);
 		BatchLoaderRegistry.RegistrationSpec<Object, Object> registration = registry.forName(dataLoaderKey);
 		if (info.getMaxBatchSize() > 0) {
-			registration.withOptions(options -> options.setMaxBatchSize(info.getMaxBatchSize()));
+			registration.withOptions((options) -> options.setMaxBatchSize(info.getMaxBatchSize()));
 		}
 
 		HandlerMethod handlerMethod = info.getHandlerMethod();
@@ -362,6 +362,7 @@ public class AnnotatedControllerConfigurer
 	 * Alternative to {@link #configure(RuntimeWiring.Builder)} that registers
 	 * data fetchers in a {@link GraphQLCodeRegistry.Builder}. This could be
 	 * used with programmatic creation of {@link graphql.schema.GraphQLSchema}.
+	 * @param codeRegistryBuilder the code registry
 	 */
 	@SuppressWarnings("rawtypes")
 	public void configure(GraphQLCodeRegistry.Builder codeRegistryBuilder) {
@@ -408,7 +409,7 @@ public class AnnotatedControllerConfigurer
 			this.argumentResolvers = argumentResolvers;
 
 			this.methodValidationHelper =
-					(helper != null ? helper.getValidationHelperFor(info.getHandlerMethod()) : null);
+					(helper != null) ? helper.getValidationHelperFor(info.getHandlerMethod()) : null;
 
 			this.exceptionResolver = exceptionResolver;
 
@@ -429,12 +430,12 @@ public class AnnotatedControllerConfigurer
 		@Override
 		public Map<String, ResolvableType> getArguments() {
 
-			Predicate<MethodParameter> argumentPredicate = p ->
+			Predicate<MethodParameter> argumentPredicate = (p) ->
 					(p.getParameterAnnotation(Argument.class) != null || p.getParameterType() == ArgumentValue.class);
 
 			return Arrays.stream(this.mappingInfo.getHandlerMethod().getMethodParameters())
 					.filter(argumentPredicate)
-					.peek(p -> p.initParameterNameDiscovery(parameterNameDiscoverer))
+					.peek((p) -> p.initParameterNameDiscovery(parameterNameDiscoverer))
 					.collect(Collectors.toMap(
 							ArgumentMethodArgumentResolver::getArgumentName,
 							ResolvableType::forMethodParameter));
@@ -443,7 +444,7 @@ public class AnnotatedControllerConfigurer
 		/**
 		 * Return the {@link HandlerMethod} used to fetch data.
 		 */
-		public HandlerMethod getHandlerMethod() {
+		HandlerMethod getHandlerMethod() {
 			return this.mappingInfo.getHandlerMethod();
 		}
 
@@ -469,13 +470,13 @@ public class AnnotatedControllerConfigurer
 				DataFetchingEnvironment env, DataFetcherHandlerMethod handlerMethod, Object result) {
 
 			if (this.subscription && result instanceof Publisher<?> publisher) {
-				result = Flux.from(publisher).onErrorResume(ex -> handleSubscriptionError(ex, env, handlerMethod));
+				result = Flux.from(publisher).onErrorResume((ex) -> handleSubscriptionError(ex, env, handlerMethod));
 			}
 			else if (result instanceof Mono) {
-				result = ((Mono<T>) result).onErrorResume(ex -> (Mono<T>) handleException(ex, env, handlerMethod));
+				result = ((Mono<T>) result).onErrorResume((ex) -> (Mono<T>) handleException(ex, env, handlerMethod));
 			}
 			else if (result instanceof Flux<?>) {
-				result = ((Flux<T>) result).onErrorResume(ex -> (Mono<T>) handleException(ex, env, handlerMethod));
+				result = ((Flux<T>) result).onErrorResume((ex) -> (Mono<T>) handleException(ex, env, handlerMethod));
 			}
 			return result;
 		}
@@ -484,7 +485,7 @@ public class AnnotatedControllerConfigurer
 				Throwable ex, DataFetchingEnvironment env, DataFetcherHandlerMethod handlerMethod) {
 
 			return this.exceptionResolver.resolveException(ex, env, handlerMethod.getBean())
-					.map(errors -> DataFetcherResult.newResult().errors(errors).build())
+					.map((errors) -> DataFetcherResult.newResult().errors(errors).build())
 					.switchIfEmpty(Mono.error(ex));
 		}
 
@@ -493,7 +494,7 @@ public class AnnotatedControllerConfigurer
 				Throwable ex, DataFetchingEnvironment env, DataFetcherHandlerMethod handlerMethod) {
 
 			return (Publisher<T>) this.exceptionResolver.resolveException(ex, env, handlerMethod.getBean())
-					.flatMap(errors -> Mono.error(new SubscriptionPublisherException(errors, ex)))
+					.flatMap((errors) -> Mono.error(new SubscriptionPublisherException(errors, ex)))
 					.switchIfEmpty(Mono.error(ex));
 		}
 

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerDetectionSupport.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import java.lang.reflect.Method;
@@ -54,13 +55,13 @@ import org.springframework.util.ClassUtils;
  * Convenient base for classes that find annotated controller method with argument
  * values resolved from a {@link graphql.schema.DataFetchingEnvironment}.
  *
+ * @param <M> the type of mapping info prepared from a controller method
  * @author Rossen Stoyanchev
  * @since 1.3
- * @param <M> the type of mapping info prepared from a controller method
  */
 public abstract class AnnotatedControllerDetectionSupport<M> implements ApplicationContextAware, InitializingBean {
 
-	protected final static boolean springSecurityPresent = ClassUtils.isPresent(
+	protected static final boolean springSecurityPresent = ClassUtils.isPresent(
 			"org.springframework.security.core.context.SecurityContext",
 			AnnotatedControllerDetectionSupport.class.getClassLoader());
 
@@ -102,6 +103,7 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 	 * that assists in binding GraphQL arguments onto
 	 * {@link org.springframework.graphql.data.method.annotation.Argument @Argument}
 	 * annotated method parameters.
+	 * @param registrar the formatter registrar
 	 */
 	public void addFormatterRegistrar(FormatterRegistrar registrar) {
 		registrar.registerFormatters(this.conversionService);
@@ -116,6 +118,7 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 	 * {@link org.springframework.graphql.data.method.annotation.Argument @Argument}
 	 * should falls back to direct field access in case the target object does
 	 * not use accessor methods.
+	 * @param fallBackOnDirectFieldAccess whether binding should fall back on direct field access
 	 * @since 1.2.0
 	 */
 	public void setFallBackOnDirectFieldAccess(boolean fallBackOnDirectFieldAccess) {
@@ -133,11 +136,9 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 	 * exceptions from non-controller {@link DataFetcher}s since exceptions from
 	 * {@code @SchemaMapping} controller methods are handled automatically at
 	 * the point of invocation.
-	 *
 	 * @return a resolver instance that can be plugged into
 	 * {@link org.springframework.graphql.execution.GraphQlSource.Builder#exceptionResolvers(List)
 	 * GraphQlSource.Builder}
-	 *
 	 * @since 1.2.0
 	 */
 	public HandlerDataFetcherExceptionResolver getExceptionResolver() {
@@ -214,15 +215,15 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 			}
 			catch (Throwable ex) {
 				// An unresolvable bean type, probably from a lazy bean - let's ignore it.
-				if (logger.isTraceEnabled()) {
-					logger.trace("Could not resolve type for bean '" + beanName + "'", ex);
+				if (this.logger.isTraceEnabled()) {
+					this.logger.trace("Could not resolve type for bean '" + beanName + "'", ex);
 				}
 			}
 			if (beanType == null || !AnnotatedElementUtils.hasAnnotation(beanType, Controller.class)) {
 				continue;
 			}
 			Class<?> beanClass = context.getType(beanName);
-			findHandlerMethods(beanName, beanClass).forEach(info -> registerHandlerMethod(info, results));
+			findHandlerMethods(beanName, beanClass).forEach((info) -> registerHandlerMethod(info, results));
 		}
 		return results;
 	}
@@ -240,8 +241,8 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 
 		Collection<M> mappingInfos = map.values();
 
-		if (logger.isTraceEnabled() && !mappingInfos.isEmpty()) {
-			logger.trace(formatMappings(userClass, mappingInfos));
+		if (this.logger.isTraceEnabled() && !mappingInfos.isEmpty()) {
+			this.logger.trace(formatMappings(userClass, mappingInfos));
 		}
 
 		return mappingInfos;
@@ -252,10 +253,10 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 
 	private String formatMappings(Class<?> handlerType, Collection<M> infos) {
 		String formattedType = Arrays.stream(ClassUtils.getPackageName(handlerType).split("\\."))
-				.map(p -> p.substring(0, 1))
+				.map((p) -> p.substring(0, 1))
 				.collect(Collectors.joining(".", "", "." + handlerType.getSimpleName()));
 		return infos.stream()
-				.map(info -> {
+				.map((info) -> {
 					Method method = getHandlerMethod(info).getMethod();
 					String methodParameters = Arrays.stream(method.getGenericParameterTypes())
 							.map(Type::getTypeName)
@@ -268,7 +269,7 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 	private void registerHandlerMethod(M info, Set<M> results) {
 		Assert.state(this.exceptionResolver != null, "afterPropertiesSet not called");
 		HandlerMethod handlerMethod = getHandlerMethod(info);
-		M existing = results.stream().filter(o -> o.equals(info)).findFirst().orElse(null);
+		M existing = results.stream().filter((o) -> o.equals(info)).findFirst().orElse(null);
 		if (existing != null && !getHandlerMethod(existing).equals(handlerMethod)) {
 			throw new IllegalStateException(
 					"Ambiguous mapping. Cannot map '" + handlerMethod.getBean() + "' method \n" +
@@ -281,9 +282,9 @@ public abstract class AnnotatedControllerDetectionSupport<M> implements Applicat
 
 	protected HandlerMethod createHandlerMethod(Method originalMethod, Object handler, Class<?> handlerType) {
 		Method method = AopUtils.selectInvocableMethod(originalMethod, handlerType);
-		return (handler instanceof String beanName ?
+		return (handler instanceof String beanName) ?
 				new HandlerMethod(beanName, obtainApplicationContext().getAutowireCapableBeanFactory(), method) :
-				new HandlerMethod(handler, method));
+				new HandlerMethod(handler, method);
 	}
 
 }

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerExceptionResolver.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import java.lang.reflect.Method;
@@ -72,7 +73,6 @@ import org.springframework.web.method.ControllerAdviceBean;
  *
  * @author Rossen Stoyanchev
  * @author Brian Clozel
- * @since 1.2.0
  */
 final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherExceptionResolver {
 
@@ -98,9 +98,9 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 	 * are validated to ensure they are within a range of supported types.
 	 * @param controllerType the controller type to register
 	 */
-	public void registerController(Class<?> controllerType) {
+	void registerController(Class<?> controllerType) {
 		this.controllerCache.computeIfAbsent(
-				controllerType, type -> new MethodResolver(findExceptionHandlers(controllerType)));
+				controllerType, (type) -> new MethodResolver(findExceptionHandlers(controllerType)));
 	}
 
 	/**
@@ -110,7 +110,7 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 	 * for use at runtime.
 	 * @param context the context to look into
 	 */
-	public void registerControllerAdvice(ApplicationContext context) {
+	void registerControllerAdvice(ApplicationContext context) {
 		Map<ControllerAdviceBean, MethodResolver> detectedControllerAdvice = new HashMap<>();
 		for (ControllerAdviceBean bean : ControllerAdviceBean.findAnnotatedBeans(context)) {
 			Class<?> beanType = bean.getBeanType();
@@ -121,9 +121,8 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 				}
 			}
 		}
-		detectedControllerAdvice.keySet().stream().sorted(OrderComparator.INSTANCE).forEach(bean -> {
-			this.controllerAdviceCache.put(bean, detectedControllerAdvice.get(bean));
-		});
+		detectedControllerAdvice.keySet().stream().sorted(OrderComparator.INSTANCE)
+				.forEach((bean) -> this.controllerAdviceCache.put(bean, detectedControllerAdvice.get(bean)));
 		if (logger.isDebugEnabled()) {
 			logger.debug("@GraphQlException methods in ControllerAdvice beans: " +
 					(this.controllerAdviceCache.isEmpty() ? "none" : this.controllerAdviceCache.size()));
@@ -134,7 +133,7 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 	private static Map<Class<? extends Throwable>, Method> findExceptionHandlers(Class<?> handlerType) {
 
 		Map<Method, GraphQlExceptionHandler> handlerMap = MethodIntrospector.selectMethods(
-				handlerType, (MethodIntrospector.MetadataLookup<GraphQlExceptionHandler>) method ->
+				handlerType, (MethodIntrospector.MetadataLookup<GraphQlExceptionHandler>) (method) ->
 						AnnotatedElementUtils.findMergedAnnotation(method, GraphQlExceptionHandler.class));
 
 		Map<Class<? extends Throwable>, Method> mappings = new HashMap<>(handlerMap.size());
@@ -230,7 +229,7 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 			while (exToExpose != null) {
 				exceptions.add(exToExpose);
 				Throwable cause = exToExpose.getCause();
-				exToExpose = (cause != exToExpose ? cause : null);
+				exToExpose = (cause != exToExpose) ? cause : null;
 			}
 			Object[] arguments = new Object[exceptions.size() + 1];
 			exceptions.toArray(arguments);  // efficient arraycopy call in ArrayList
@@ -278,7 +277,7 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 		 * @return the exception handler to use, or {@code null} if no match
 		 */
 		@Nullable
-		public MethodHolder resolveMethod(Throwable exception) {
+		MethodHolder resolveMethod(Throwable exception) {
 			MethodHolder method = resolveMethodByExceptionType(exception.getClass());
 			if (method == null) {
 				Throwable cause = exception.getCause();
@@ -296,7 +295,7 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 				method = getMappedMethod(exceptionType);
 				this.resolvedExceptionCache.put(exceptionType, method);
 			}
-			return (method != NO_MATCH ? method : null);
+			return (method != NO_MATCH) ? method : null;
 		}
 
 		private MethodHolder getMappedMethod(Class<? extends Throwable> exceptionType) {
@@ -342,11 +341,11 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 			this.adapter = ReturnValueAdapter.createFor(this.returnType);
 		}
 
-		public Method getMethod() {
+		Method getMethod() {
 			return this.method;
 		}
 
-		public Mono<List<GraphQLError>> adapt(@Nullable Object result, Throwable ex) {
+		Mono<List<GraphQLError>> adapt(@Nullable Object result, Throwable ex) {
 			return this.adapter.adapt(result, this.returnType, ex);
 		}
 
@@ -421,24 +420,24 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 		}
 
 
-		/** Adapter for void */
+		/* Adapter for void */
 		ReturnValueAdapter forVoid = (result, returnType, ex) -> Mono.just(Collections.emptyList());
 
-		/** Adapter for a single GraphQLError */
+		/* Adapter for a single GraphQLError */
 		ReturnValueAdapter forSingleError = (result, returnType, ex) ->
-				(result == null ?
-						Mono.empty() :
-						Mono.just(Collections.singletonList((GraphQLError) result)));
+				(result != null) ?
+						Mono.just(Collections.singletonList((GraphQLError) result)) :
+						Mono.empty();
 
-		/** Adapter for a collection of GraphQLError's */
+		/* Adapter for a collection of GraphQLError's */
 		ReturnValueAdapter forCollection = (result, returnType, ex) ->
-				(result == null ?
-						Mono.empty() :
-						Mono.just((result instanceof List ?
+				(result != null) ?
+						Mono.just((result instanceof List) ?
 								(List<GraphQLError>) result :
-								new ArrayList<>((Collection<GraphQLError>) result))));
+								new ArrayList<>((Collection<GraphQLError>) result)) :
+						Mono.empty();
 
-		/** Adapter for Object */
+		/* Adapter for Object */
 		ReturnValueAdapter forObject = (result, returnType, ex) -> {
 			if (result == null) {
 				return Mono.empty();
@@ -458,15 +457,15 @@ final class AnnotatedControllerExceptionResolver implements HandlerDataFetcherEx
 			}
 		};
 
-		/** Adapter for {@code Mono<Void>} */
+		/* Adapter for {@code Mono<Void>} */
 		ReturnValueAdapter forMonoVoid = (result, returnType, ex) ->
-				(result == null ? Mono.empty() : Mono.just(Collections.emptyList()));
+				(result != null) ? Mono.just(Collections.emptyList()) : Mono.empty();
 
-		/** Adapter for a {@code Mono} wrapping any of the other synchronous return value types */
+		/* Adapter for a {@code Mono} wrapping any of the other synchronous return value types */
 		ReturnValueAdapter forMono = (result, returnType, ex) ->
-				(result == null ?
-						Mono.empty() :
-						((Mono<?>) result).flatMap(o -> forObject.adapt(o, returnType, ex)).switchIfEmpty(Mono.error(ex)));
+				(result != null) ?
+						((Mono<?>) result).flatMap((o) -> forObject.adapt(o, returnType, ex)).switchIfEmpty(Mono.error(ex)) :
+						Mono.empty();
 	}
 
 }

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ArgumentMethodArgumentResolver.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import graphql.schema.DataFetchingEnvironment;
@@ -83,6 +84,9 @@ public class ArgumentMethodArgumentResolver implements HandlerMethodArgumentReso
 
 	/**
 	 * Perform the binding with the configured {@link #getArgumentBinder() binder}.
+	 * @param environment for access to the arguments
+	 * @param name the name of an argument, or {@code null} to use the full map
+	 * @param targetType the type of Object to create
 	 * @since 1.3
 	 */
 	@Nullable

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ArgumentValueValueExtractor.java

@@ -19,22 +19,24 @@ package org.springframework.graphql.data.method.annotation.support;
 import jakarta.validation.valueextraction.ExtractedValue;
 import jakarta.validation.valueextraction.UnwrapByDefault;
 import jakarta.validation.valueextraction.ValueExtractor;
+
 import org.springframework.graphql.data.ArgumentValue;
 
 /**
  * {@link ValueExtractor} that enables {@code @Valid} with {@link ArgumentValue},
  * and helps to extract the value from it.
  *
+ * @author Rossen Stoyanchev
  * @since 1.2.2
  */
 @UnwrapByDefault
 public final class ArgumentValueValueExtractor implements ValueExtractor<ArgumentValue<@ExtractedValue ?>> {
 
-    @Override
-    public void extractValues(ArgumentValue<?> argumentValue, ValueReceiver receiver) {
-        if (!argumentValue.isOmitted()) {
-            receiver.value(null, argumentValue.value());
-        }
-    }
+	@Override
+	public void extractValues(ArgumentValue<?> argumentValue, ValueReceiver receiver) {
+		if (!argumentValue.isOmitted()) {
+			receiver.value(null, argumentValue.value());
+		}
+	}
 
 }

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ArgumentsMethodArgumentResolver.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import graphql.schema.DataFetchingEnvironment;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AuthenticationPrincipalArgumentResolver.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import java.lang.annotation.Annotation;
@@ -97,7 +98,7 @@ public class AuthenticationPrincipalArgumentResolver implements HandlerMethodArg
 	@Override
 	public Object resolveArgument(MethodParameter parameter, DataFetchingEnvironment environment) throws Exception {
 		return getCurrentAuthentication(parameter)
-				.mapNotNull(auth -> resolvePrincipal(parameter, auth.getPrincipal()))
+				.mapNotNull((auth) -> resolvePrincipal(parameter, auth.getPrincipal()))
 				.transform((argument) -> isPublisherOrMono(parameter) ? Mono.just(argument) : argument);
 	}
 
@@ -109,7 +110,7 @@ public class AuthenticationPrincipalArgumentResolver implements HandlerMethodArg
 	@SuppressWarnings("unchecked")
 	private Mono<Authentication> getCurrentAuthentication(MethodParameter parameter) {
 		Object value = PrincipalMethodArgumentResolver.resolveAuthentication(parameter);
-		return (value instanceof Authentication auth ? Mono.just(auth) : (Mono<Authentication>) value);
+		return (value instanceof Authentication auth) ? Mono.just(auth) : (Mono<Authentication>) value;
 	}
 
 	@Nullable

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/BatchLoaderHandlerMethod.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import java.security.Principal;
@@ -50,7 +51,7 @@ import org.springframework.util.ClassUtils;
  */
 public class BatchLoaderHandlerMethod extends InvocableHandlerMethodSupport {
 
-	private final static boolean springSecurityPresent = ClassUtils.isPresent(
+	private static final boolean springSecurityPresent = ClassUtils.isPresent(
 			"org.springframework.security.core.context.SecurityContext",
 			AnnotatedControllerConfigurer.class.getClassLoader());
 
@@ -66,7 +67,6 @@ public class BatchLoaderHandlerMethod extends InvocableHandlerMethodSupport {
 	/**
 	 * Invoke the underlying batch loader method with a collection of keys to
 	 * return a Map of key-value pairs.
-	 *
 	 * @param keys the keys for which to load values
 	 * @param environment the environment available to batch loaders
 	 * @param <K> the type of keys in the map
@@ -80,7 +80,7 @@ public class BatchLoaderHandlerMethod extends InvocableHandlerMethodSupport {
 			Object result = doInvoke(environment.getContext(), args);
 			return toMonoMap(result);
 		}
-		return toArgsMono(args).flatMap(argValues -> {
+		return toArgsMono(args).flatMap((argValues) -> {
 			Object result = doInvoke(environment.getContext(), argValues);
 			return toMonoMap(result);
 		});
@@ -89,7 +89,6 @@ public class BatchLoaderHandlerMethod extends InvocableHandlerMethodSupport {
 	/**
 	 * Invoke the underlying batch loader method with a collection of input keys
 	 * to return a collection of matching values.
-	 *
 	 * @param keys the keys for which to load values
 	 * @param environment the environment available to batch loaders
 	 * @param <V> the type of values returned
@@ -101,7 +100,7 @@ public class BatchLoaderHandlerMethod extends InvocableHandlerMethodSupport {
 			Object result = doInvoke(environment.getContext(), args);
 			return toFlux(result);
 		}
-		return toArgsMono(args).flatMapMany(resolvedArgs -> {
+		return toArgsMono(args).flatMapMany((resolvedArgs) -> {
 			Object result = doInvoke(environment.getContext(), resolvedArgs);
 			return toFlux(result);
 		});
@@ -164,7 +163,7 @@ public class BatchLoaderHandlerMethod extends InvocableHandlerMethodSupport {
 	}
 
 	private boolean doesNotHaveAsyncArgs(Object[] args) {
-		return Arrays.stream(args).noneMatch(arg -> arg instanceof Mono);
+		return Arrays.stream(args).noneMatch((arg) -> arg instanceof Mono);
 	}
 
 	@SuppressWarnings("unchecked")
@@ -176,7 +175,7 @@ public class BatchLoaderHandlerMethod extends InvocableHandlerMethodSupport {
 			return (Mono<Map<K, V>>) result;
 		}
 		else if (result instanceof CompletableFuture) {
-			return Mono.fromFuture((CompletableFuture<? extends Map<K,V>>) result);
+			return Mono.fromFuture((CompletableFuture<? extends Map<K, V>>) result);
 		}
 		return Mono.error(new IllegalStateException("Unexpected return value: " + result));
 	}

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ContextValueMethodArgumentResolver.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import java.lang.annotation.Annotation;
@@ -72,7 +73,7 @@ public class ContextValueMethodArgumentResolver implements HandlerMethodArgument
 			@Nullable GraphQLContext graphQlContext) {
 
 		Class<?> parameterType = parameter.getParameterType();
-		Object value = (graphQlContext != null ? graphQlContext.get(contextValueName) : null);
+		Object value = (graphQlContext != null) ? graphQlContext.get(contextValueName) : null;
 
 		boolean isOptional = parameterType.equals(Optional.class);
 		boolean isMono = parameterType.equals(Mono.class);
@@ -85,14 +86,14 @@ public class ContextValueMethodArgumentResolver implements HandlerMethodArgument
 			if (value == null) {
 				value = Mono.empty();
 			}
-			else if (!( value instanceof Mono)) {
+			else if (!(value instanceof Mono)) {
 				value = Mono.just(value);
 			}
 			return Mono.just(value);
 		}
 
 		if (isOptional) {
-			return (value instanceof Optional ? value : Optional.ofNullable(value));
+			return (value instanceof Optional) ? value : Optional.ofNullable(value);
 		}
 
 		return value;

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/ContinuationHandlerMethodArgumentResolver.java

@@ -13,9 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import graphql.schema.DataFetchingEnvironment;
+
 import org.springframework.core.MethodParameter;
 import org.springframework.graphql.data.method.HandlerMethodArgumentResolver;
 
@@ -27,14 +29,14 @@ import org.springframework.graphql.data.method.HandlerMethodArgumentResolver;
  */
 public class ContinuationHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver {
 
-    @Override
-    public boolean supportsParameter(MethodParameter parameter) {
-        return "kotlin.coroutines.Continuation".equals(parameter.getParameterType().getName());
-    }
+	@Override
+	public boolean supportsParameter(MethodParameter parameter) {
+		return "kotlin.coroutines.Continuation".equals(parameter.getParameterType().getName());
+	}
 
-    @Override
-    public Object resolveArgument(MethodParameter parameter, DataFetchingEnvironment environment) {
-        return null;
-    }
+	@Override
+	public Object resolveArgument(MethodParameter parameter, DataFetchingEnvironment environment) {
+		return null;
+	}
 
 }

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/DataFetcherHandlerMethod.java

@@ -13,9 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.graphql.data.method.annotation.support;
 
 import java.util.Arrays;
+import java.util.concurrent.Callable;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executor;
 import java.util.function.BiConsumer;
@@ -49,6 +51,7 @@ public class DataFetcherHandlerMethod extends DataFetcherHandlerMethodSupport {
 	 * @param handlerMethod the handler method
 	 * @param resolvers the argument resolvers
 	 * @param validationHelper to apply bean validation with
+	 * @param executor an {@link Executor} to use for {@link Callable} return values
 	 * @param subscription whether the field being fetched is of subscription type
 	 */
 	public DataFetcherHandlerMethod(
@@ -58,7 +61,7 @@ public class DataFetcherHandlerMethod extends DataFetcherHandlerMethodSupport {
 
 		super(handlerMethod, resolvers, executor);
 		Assert.isTrue(!resolvers.getResolvers().isEmpty(), "No argument resolvers");
-		this.validationHelper = (validationHelper != null ? validationHelper : (controller, args) -> {});
+		this.validationHelper = (validationHelper != null) ? validationHelper : (controller, args) -> { };
 		this.subscription = subscription;
 	}
 
@@ -72,9 +75,7 @@ public class DataFetcherHandlerMethod extends DataFetcherHandlerMethodSupport {
 	 * The {@code providedArgs} parameter however may supply argument values to
 	 * be used directly, i.e. without argument resolution. Provided argument
 	 * values are checked before argument resolvers.
-	 *
 	 * @param environment the environment to resolve arguments from
-	 *
 	 * @return the raw value returned by the invoked method, possibly a
 	 * {@code Mono} in case a method argument requires asynchronous resolution;
 	 * {@code Mono<Throwable>} is returned if invocation fails.
@@ -87,6 +88,8 @@ public class DataFetcherHandlerMethod extends DataFetcherHandlerMethodSupport {
 	/**
 	 * Variant of {@link #invoke(DataFetchingEnvironment)} that also accepts
 	 * "given" arguments, which are matched by type.
+	 * @param environment the data fetching environment
+	 * @param providedArgs additional arguments to be matched by their type
 	 * @since 1.2.0
 	 */
 	@Nullable
@@ -99,17 +102,17 @@ public class DataFetcherHandlerMethod extends DataFetcherHandlerMethodSupport {
 			return Mono.error(ex);
 		}
 
-		if (Arrays.stream(args).noneMatch(arg -> arg instanceof Mono)) {
+		if (Arrays.stream(args).noneMatch((arg) -> arg instanceof Mono)) {
 			return validateAndInvoke(args, environment);
 		}
 
 		return this.subscription ?
-				toArgsMono(args).flatMapMany(argValues -> {
+				toArgsMono(args).flatMapMany((argValues) -> {
 					Object result = validateAndInvoke(argValues, environment);
 					Assert.state(result instanceof Publisher, "Expected a Publisher from a Subscription response");
 					return Flux.from((Publisher<?>) result);
 				}) :
-				toArgsMono(args).flatMap(argValues -> {
+				toArgsMono(args).flatMap((argValues) -> {
 					Object result = validateAndInvoke(argValues, environment);
 					if (result instanceof Mono<?> mono) {
 						return mono;