Support application/graphql with charset information

Prior to this commit, gh-948 added a fallback support for the
"application/graphql" content-type sent by clients. This media type is
not widely used and advised against by the spec group.

This fallback checked for an exact match of the content type, not taking
into account potential media type parameters such as charset.

This commit ensure that a `MediaType#include` comparison is used to
trigger the fallback.

Fixes gh-1036

spring-graphql/src/main/java/org/springframework/graphql/server/webflux/AbstractGraphQlHttpHandler.java

@@ -36,6 +36,7 @@
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 import org.springframework.web.reactive.function.server.ServerRequest;
 import org.springframework.web.reactive.function.server.ServerResponse;
 import org.springframework.web.server.UnsupportedMediaTypeStatusException;
@@ -114,15 +115,20 @@ private Mono<SerializableGraphQlRequest> readRequest(ServerRequest serverRequest
 	private static Mono<SerializableGraphQlRequest> applyApplicationGraphQlFallback(
 			UnsupportedMediaTypeStatusException ex, ServerRequest request) {
 
-		// Spec requires application/json but some clients still use application/graphql
-		return "application/graphql".equals(request.headers().firstHeader(HttpHeaders.CONTENT_TYPE)) ?
-				ServerRequest.from(request)
-						.headers((headers) -> headers.setContentType(MediaType.APPLICATION_JSON))
-						.body(request.bodyToFlux(DataBuffer.class))
-						.build()
-						.bodyToMono(SerializableGraphQlRequest.class)
-						.log() :
-				Mono.error(ex);
+		String contentTypeHeader = request.headers().firstHeader(HttpHeaders.CONTENT_TYPE);
+		if (StringUtils.hasText(contentTypeHeader)) {
+			MediaType contentType = MediaType.parseMediaType(contentTypeHeader);
+			MediaType applicationGraphQl = MediaType.parseMediaType("application/graphql");
+
+			// Spec requires application/json but some clients still use application/graphql
+			return applicationGraphQl.includes(contentType) ? ServerRequest.from(request)
+					.headers((headers) -> headers.setContentType(MediaType.APPLICATION_JSON))
+					.body(request.bodyToFlux(DataBuffer.class))
+					.build()
+					.bodyToMono(SerializableGraphQlRequest.class)
+					.log() : Mono.error(ex);
+		}
+		return Mono.error(ex);
 	}
 
 	/**

spring-graphql/src/main/java/org/springframework/graphql/server/webmvc/AbstractGraphQlHttpHandler.java

@@ -49,6 +49,7 @@
 import org.springframework.util.IdGenerator;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
+import org.springframework.util.StringUtils;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
 import org.springframework.web.server.ServerWebInputException;
 import org.springframework.web.servlet.ModelAndView;
@@ -170,17 +171,22 @@ private GraphQlRequest readBody(ServerRequest request) throws ServletException {
 	private static SerializableGraphQlRequest applyApplicationGraphQlFallback(
 			ServerRequest request, HttpMediaTypeNotSupportedException ex) throws HttpMediaTypeNotSupportedException {
 
-		// Spec requires application/json but some clients still use application/graphql
-		if ("application/graphql".equals(request.headers().firstHeader(HttpHeaders.CONTENT_TYPE))) {
-			try {
-				request = ServerRequest.from(request)
-						.headers((headers) -> headers.setContentType(MediaType.APPLICATION_JSON))
-						.body(request.body(byte[].class))
-						.build();
-				return request.body(SerializableGraphQlRequest.class);
-			}
-			catch (Throwable ex2) {
-				// ignore
+		String contentTypeHeader = request.headers().firstHeader(HttpHeaders.CONTENT_TYPE);
+		if (StringUtils.hasText(contentTypeHeader)) {
+			MediaType contentType = MediaType.parseMediaType(contentTypeHeader);
+			MediaType applicationGraphQl = MediaType.parseMediaType("application/graphql");
+			// Spec requires application/json but some clients still use application/graphql
+			if (applicationGraphQl.includes(contentType)) {
+				try {
+					request = ServerRequest.from(request)
+							.headers((headers) -> headers.setContentType(MediaType.APPLICATION_JSON))
+							.body(request.body(byte[].class))
+							.build();
+					return request.body(SerializableGraphQlRequest.class);
+				}
+				catch (Throwable ex2) {
+					// ignore
+				}
 			}
 		}
 		throw ex;

spring-graphql/src/test/java/org/springframework/graphql/server/webflux/GraphQlHttpHandlerTests.java

@@ -99,6 +99,22 @@ void shouldSupportApplicationGraphQl() throws Exception {
 				.verifyComplete();
 	}
 
+	@Test
+	void shouldSupportApplicationGraphQlWithCharset() throws Exception {
+		String document = "{greeting}";
+		MockServerHttpRequest httpRequest = MockServerHttpRequest.post("/")
+				.contentType(MediaType.parseMediaType("application/graphql;charset=UTF-8"))
+				.accept(MediaType.ALL)
+				.body(initRequestBody(document));
+
+		MockServerHttpResponse response = handleRequest(httpRequest, this.greetingHandler);
+
+		assertThat(response.getHeaders().getContentType()).isEqualTo(MediaType.APPLICATION_JSON);
+		StepVerifier.create(response.getBodyAsString())
+				.expectNext("{\"data\":{\"greeting\":\"Hello\"}}")
+				.verifyComplete();
+	}
+
 	@Test
 	void shouldProduceApplicationGraphQl() throws Exception {
 		MockServerHttpRequest httpRequest = MockServerHttpRequest.post("/")

spring-graphql/src/test/java/org/springframework/graphql/server/webmvc/GraphQlHttpHandlerTests.java

@@ -80,6 +80,15 @@ void shouldSupportApplicationGraphQl() throws Exception {
 		assertThat(response.getContentAsString()).isEqualTo("{\"data\":{\"greeting\":\"Hello\"}}");
 	}
 
+	@Test
+	void shouldSupportApplicationGraphQlWithCharset() throws Exception {
+		MockHttpServletRequest request = createServletRequest("{ greeting }", "*/*");
+		request.setContentType("application/graphql;charset=UTF-8");
+
+		MockHttpServletResponse response = handleRequest(request, this.greetingHandler);
+		assertThat(response.getContentAsString()).isEqualTo("{\"data\":{\"greeting\":\"Hello\"}}");
+	}
+
 	@Test
 	void shouldProduceApplicationGraphQl() throws Exception {
 		MockHttpServletRequest request = createServletRequest("{ greeting }", MediaType.APPLICATION_GRAPHQL_RESPONSE_VALUE);