Only scan for *.graphqls and *.gqls schema files

Prior to this commit, the auto-configuration was scanning for
`"*.graphql,*.gql,*.graphqls,*.gqls"` files in the configured locations.
This was not flexible enough, as developers could not customize the
considered file extensions when scanning for files.

This commit provides a new `spring.graphql.schema.file-extensions`
configuration property that enables such customizations.

Because `"*.graphql,*.gql"` extensions seem to be tied to queries
(and not schemas), this commit also changes the default value to only
consider the `"*.graphqls,*.gqls"` file extensions by default.

Closes gh-134
Closes gh-135

graphql-spring-boot-starter/src/main/java/org/springframework/graphql/boot/GraphQlAutoConfiguration.java

@@ -56,8 +56,6 @@ public class GraphQlAutoConfiguration {
 
 	private static final Log logger = LogFactory.getLog(GraphQlAutoConfiguration.class);
 
-	private static final String[] SCHEMA_FILES_EXTENSIONS = new String[] {"*.graphqls", "*.graphql", "*.gql", "*.gqls"};
-
 	@Bean
 	public GraphQlSource graphQlSource(ResourcePatternResolver resourcePatternResolver, GraphQlProperties properties,
 			ObjectProvider<DataFetcherExceptionResolver> exceptionResolversProvider,
@@ -65,7 +63,8 @@ public class GraphQlAutoConfiguration {
 			ObjectProvider<GraphQlSourceBuilderCustomizer> sourceCustomizers,
 			ObjectProvider<RuntimeWiringConfigurer> wiringConfigurers) throws IOException {
 
-		List<Resource> schemaResources = resolveSchemaResources(resourcePatternResolver, properties.getSchema().getLocations());
+		List<Resource> schemaResources = resolveSchemaResources(resourcePatternResolver, properties.getSchema().getLocations(),
+				properties.getSchema().getFileExtensions());
 		GraphQlSource.Builder builder = GraphQlSource.builder()
 				.schemaResources(schemaResources.toArray(new Resource[0]))
 				.exceptionResolvers(exceptionResolversProvider.orderedStream().collect(Collectors.toList()))
@@ -80,15 +79,16 @@ public class GraphQlAutoConfiguration {
 		}
 	}
 
-	private List<Resource> resolveSchemaResources(ResourcePatternResolver resolver, List<String> schemaLocations) throws IOException {
+	private List<Resource> resolveSchemaResources(ResourcePatternResolver resolver, String[] schemaLocations, String[] fileExtensions) {
 		List<Resource> schemaResources = new ArrayList<>();
 		for (String location : schemaLocations) {
-			for (String extension : SCHEMA_FILES_EXTENSIONS) {
+			for (String extension : fileExtensions) {
+				String resourcePattern = location + "*" + extension;
 				try {
-					schemaResources.addAll(Arrays.asList(resolver.getResources(location + extension)));
+					schemaResources.addAll(Arrays.asList(resolver.getResources(resourcePattern)));
 				}
 				catch (IOException ex) {
-					logger.debug("Could not resolve schema location: '" + location + extension + "'", ex);
+					logger.debug("Could not resolve schema location: '" + resourcePattern + "'", ex);
 				}
 			}
 		}

graphql-spring-boot-starter/src/main/java/org/springframework/graphql/boot/GraphQlProperties.java

@@ -17,10 +17,7 @@
 package org.springframework.graphql.boot;
 
 import java.time.Duration;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
+import java.util.Arrays;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
@@ -67,24 +64,38 @@ public class GraphQlProperties {
 	public static class Schema {
 
 		/**
-		 * Locations of GraphQL '*.graphqls' schema files.
+		 * Locations of GraphQL schema files.
 		 */
-		private List<String> locations = new ArrayList<>(Collections.singletonList("classpath:graphql/"));
+		private String[] locations = new String[] { "classpath:graphql/"};
+
+		/**
+		 * File extensions for GraphQL schema files.
+		 */
+		private String[] fileExtensions = new String[] { ".graphqls", ".gqls"};
+
 
 		private final Printer printer = new Printer();
 
-		public List<String> getLocations() {
+		public String[] getLocations() {
 			return this.locations;
 		}
 
-		public void setLocations(List<String> locations) {
+		public void setLocations(String[] locations) {
 			this.locations = appendSlashIfNecessary(locations);
 		}
 
-		private List<String> appendSlashIfNecessary(List<String> locations) {
-			return locations.stream()
+		public String[] getFileExtensions() {
+			return this.fileExtensions;
+		}
+
+		public void setFileExtensions(String[] fileExtensions) {
+			this.fileExtensions = fileExtensions;
+		}
+
+		private String[] appendSlashIfNecessary(String[] locations) {
+			return Arrays.stream(locations)
 					.map(location -> location.endsWith("/") ? location : location + "/")
-					.collect(Collectors.toList());
+					.toArray(String[]::new);
 		}
 
 		public Printer getPrinter() {

graphql-spring-boot-starter/src/main/java/org/springframework/graphql/boot/InvalidSchemaLocationsException.java

@@ -35,11 +35,11 @@ public class InvalidSchemaLocationsException extends NestedRuntimeException {
 
 	private final List<SchemaLocation> schemaLocations;
 
-	public InvalidSchemaLocationsException(List<String> locations, ResourcePatternResolver resolver) {
+	public InvalidSchemaLocationsException(String[] locations, ResourcePatternResolver resolver) {
 		this(locations, resolver, null);
 	}
 
-	public InvalidSchemaLocationsException(List<String> locations, ResourcePatternResolver resolver, Throwable cause) {
+	public InvalidSchemaLocationsException(String[] locations, ResourcePatternResolver resolver, Throwable cause) {
 		super("No schema file could be found in the provided locations.", cause);
 		List<SchemaLocation> providedLocations = new ArrayList<>();
 		for (String location : locations) {

graphql-spring-boot-starter/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -4,6 +4,10 @@
       "name": "spring.graphql.schema.locations",
       "defaultValue": "classpath:graphql/"
     },
+    {
+      "name": "spring.graphql.schema.file-extensions",
+      "defaultValue": ".graphqls,.gqls"
+    },
     {
       "name": "management.metrics.graphql.autotime.enabled",
       "description": "Whether to automatically time graphql requests.",

graphql-spring-boot-starter/src/test/java/org/springframework/graphql/boot/GraphQlAutoConfigurationTests.java

@@ -62,7 +62,8 @@ class GraphQlAutoConfigurationTests {
 
 	@Test
 	void shouldScanLocationsForSchemaFiles() {
-		this.contextRunner.withPropertyValues("spring.graphql.schema.locations:classpath:schema/")
+		this.contextRunner.withPropertyValues("spring.graphql.schema.locations:classpath:schema/",
+						"spring.graphql.schema.file-extensions:.gql,.gqls,.graphql,.graphqls")
 				.run((context) -> {
 					assertThat(context).hasSingleBean(GraphQlSource.class);
 					GraphQlSource graphQlSource = context.getBean(GraphQlSource.class);

samples/webmvc-http/src/main/resources/application.properties

@@ -1,3 +1,5 @@
 management.endpoints.web.exposure.include=health,metrics,info
 
-spring.graphql.schema.printer.enabled=true
+spring.graphql.schema.printer.enabled=true
+
+spring.graph