Polishing Javadoc and in security sample

samples/webmvc-http-security/src/main/java/io/spring/sample/graphql/SalaryService.java

@@ -2,8 +2,6 @@ package io.spring.sample.graphql;
 
 import java.math.BigDecimal;
 
-import reactor.core.publisher.Mono;
-
 import org.springframework.security.access.annotation.Secured;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.stereotype.Component;

samples/webmvc-http-security/src/main/java/io/spring/sample/graphql/SecurityDataFetcherExceptionResolver.java

@@ -1,8 +1,12 @@
 package io.spring.sample.graphql;
 
+import java.util.Collections;
+import java.util.List;
+
 import graphql.GraphQLError;
 import graphql.GraphqlErrorBuilder;
 import graphql.schema.DataFetchingEnvironment;
+
 import org.springframework.graphql.execution.ErrorType;
 import org.springframework.graphql.execution.SyncDataFetcherExceptionResolver;
 import org.springframework.security.access.AccessDeniedException;
@@ -15,9 +19,6 @@ import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.stereotype.Component;
 import org.springframework.util.Assert;
 
-import java.util.Arrays;
-import java.util.List;
-
 @Component
 public class SecurityDataFetcherExceptionResolver implements SyncDataFetcherExceptionResolver {
 
@@ -45,7 +46,7 @@ public class SecurityDataFetcherExceptionResolver implements SyncDataFetcherExce
 	}
 
 	private List<GraphQLError> unauthorized(DataFetchingEnvironment environment) {
-		return Arrays.asList(
+		return Collections.singletonList(
 				GraphqlErrorBuilder.newError(environment)
 						.errorType(ErrorType.UNAUTHORIZED)
 						.message("Unauthorized")
@@ -53,7 +54,7 @@ public class SecurityDataFetcherExceptionResolver implements SyncDataFetcherExce
 	}
 
 	private List<GraphQLError> forbidden(DataFetchingEnvironment environment) {
-		return Arrays.asList(
+		return Collections.singletonList(
 				GraphqlErrorBuilder.newError(environment)
 						.errorType(ErrorType.FORBIDDEN)
 						.message("Forbidden")

samples/webmvc-http/src/main/java/io/spring/sample/graphql/greeting/RequestAttributesAccessor.java

@@ -15,7 +15,6 @@
  */
 package io.spring.sample.graphql.greeting;
 
-import java.util.Collections;
 import java.util.Map;
 
 import org.springframework.graphql.execution.ThreadLocalAccessor;
@@ -30,29 +29,23 @@ import org.springframework.web.context.request.RequestContextHolder;
 @Component
 public class RequestAttributesAccessor implements ThreadLocalAccessor {
 
-	private static final String ATTRIBUTES_KEY = RequestAttributesAccessor.class.getName() + ".requestAttributes";
+	private static final String KEY = RequestAttributesAccessor.class.getName();
 
 	@Override
 	public void extractValues(Map<String, Object> container) {
-		RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
-		if (attributes != null) {
-			container.put(ATTRIBUTES_KEY, attributes);
-		}
+		container.put(KEY, RequestContextHolder.getRequestAttributes());
 	}
 
 	@Override
 	public void restoreValues(Map<String, Object> values) {
-		RequestAttributes attributes = (RequestAttributes) values.get(ATTRIBUTES_KEY);
-		if (attributes != null) {
-			RequestContextHolder.setRequestAttributes(attributes);
+		if (values.containsKey(KEY)) {
+			RequestContextHolder.setRequestAttributes((RequestAttributes) values.get(KEY));
 		}
 	}
 
 	@Override
 	public void resetValues(Map<String, Object> values) {
-		if (values.get(ATTRIBUTES_KEY) != null) {
-			RequestContextHolder.resetRequestAttributes();
-		}
+		RequestContextHolder.resetRequestAttributes();
 	}
 
 }

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

@@ -31,8 +31,9 @@ import org.springframework.util.CollectionUtils;
 
 /**
  * Common representation for GraphQL request input. This can be converted to
- * {@link ExecutionInput} via {@link #toExecutionInput()} and the {@code ExecutionInput}
- * further customized via {@link #configureExecutionInput(BiFunction)}.
+ * {@link ExecutionInput} via {@link #toExecutionInput()} and the
+ * {@code ExecutionInput} further customized via
+ * {@link #configureExecutionInput(BiFunction)}.
  *
  * @author Rossen Stoyanchev
  * @since 1.0.0

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

@@ -93,6 +93,8 @@ import org.springframework.util.MultiValueMap;
  * @see ReactiveQuerydslPredicateExecutor
  * @see Predicate
  * @see QuerydslBinderCustomizer
+ * @see <a href="https://docs.spring.io/spring-data/commons/docs/current/reference/html/#core.extensions.querydsl">
+ * Spring Data Querydsl extension</a>
  */
 public abstract class QuerydslDataFetcher<T> {
 

spring-graphql/src/main/java/org/springframework/graphql/data/package-info.java

@@ -15,7 +15,8 @@
  */
 
 /**
- * Support for integrating Spring Data data fetchers.
+ * Spring Data support for GraphQL, including built-in Querydsl
+ * {@link graphql.schema.DataFetcher} implementations.
  */
 @NonNullApi
 @NonNullFields

spring-graphql/src/main/java/org/springframework/graphql/execution/DataFetcherExceptionResolver.java

@@ -23,9 +23,12 @@ import graphql.schema.DataFetchingEnvironment;
 import reactor.core.publisher.Mono;
 
 /**
- * Contract to resolve exceptions raised by {@link graphql.schema.DataFetcher}'s to
- * {@code GraphQLError}'s to add to the GraphQL response. Implementations are typically
- * declared as beans in Spring configuration and invoked in order until one emits a List.
+ * Contract for resolving exceptions from {@link graphql.schema.DataFetcher}'s
+ * to {@code GraphQLError}'s to be added to the GraphQL response, possibly also
+ * using Spring's {@link graphql.ErrorType} for the error category.
+ *
+ * <p>Implementations are typically declared as beans in Spring configuration
+ * and invoked in order until one emits a List.
  *
  * @author Rossen Stoyanchev
  * @since 1.0.0
@@ -35,17 +38,19 @@ public interface DataFetcherExceptionResolver {
 
 	/**
 	 * Resolve the given exception and return the error(s) to add to the response.
-	 * <p>
-	 * Implementations can use
-	 * {@link graphql.GraphqlErrorBuilder#newError(DataFetchingEnvironment)} to create an
-	 * error with the coordinates of the target field, and use {@link ErrorType} to
-	 * specify a category for the error.
+	 *
+	 * <p>Implementations can use
+	 * {@link graphql.GraphqlErrorBuilder#newError(DataFetchingEnvironment)} to
+	 * create an error with the coordinates of the target field, and use
+	 * {@link ErrorType} to specify a category for the error.
+	 *
 	 * @param exception the exception to resolve
 	 * @param environment the environment for the invoked {@code DataFetcher}
-	 * @return a {@code Mono} with errors to add to the GraphQL response; if the
-	 * {@code Mono} completes with an empty List, the exception is resolved without any
-	 * errors added to the response; if the {@code Mono} completes empty, without emitting
-	 * a List, the exception remains unresolved and gives other resolvers a chance.
+	 * @return a {@code Mono} with errors to add to the GraphQL response;
+	 * if the {@code Mono} completes with an empty List, the exception is resolved
+	 * without any errors added to the response; if the {@code Mono} completes
+	 * empty, without emitting a List, the exception remains unresolved and gives
+	 * other resolvers a chance.
 	 */
 	Mono<List<GraphQLError>> resolveException(Throwable exception, DataFetchingEnvironment environment);
 

spring-graphql/src/main/java/org/springframework/graphql/execution/DefaultGraphQlSourceBuilder.java

@@ -46,7 +46,7 @@ import org.springframework.util.Assert;
  */
 class DefaultGraphQlSourceBuilder implements GraphQlSource.Builder {
 
-	private List<Resource> schemaResources = new ArrayList<>();
+	private final List<Resource> schemaResources = new ArrayList<>();
 
 	private RuntimeWiring runtimeWiring = RuntimeWiring.newRuntimeWiring().build();