From 76abf7707753adabe17331d5806a4cd300e6bd58 Mon Sep 17 00:00:00 2001
From: Rossen Stoyanchev <rstoyanchev@vmware.com>
Date: Tue, 17 May 2011 13:02:48 +0000
Subject: [PATCH] Use request attribute to check producible media types when
 writing to the response body

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@4314 50f2f4bb-b051-0410-bef5-90022cba6387
---
 .../web/servlet/HandlerMapping.java           |  8 +++
 .../RequestMappingHandlerMapping.java         | 13 +++-
 ...stractMessageConverterMethodProcessor.java | 71 +++++++++----------
 .../support/HttpEntityMethodProcessor.java    |  5 +-
 .../RequestResponseBodyMethodProcessor.java   | 10 ++-
 .../HttpEntityMethodProcessorTests.java       |  7 +-
 ...questResponseBodyMethodProcessorTests.java |  4 +-
 7 files changed, 68 insertions(+), 50 deletions(-)

diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/HandlerMapping.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/HandlerMapping.java
index c95e6ede0f9..8c381b6c469 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/HandlerMapping.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/HandlerMapping.java
@@ -92,6 +92,14 @@ public interface HandlerMapping {
 	 */
 	String URI_TEMPLATE_VARIABLES_ATTRIBUTE = HandlerMapping.class.getName() + ".uriTemplateVariables";
 
+	/**
+	 * Name of the {@link HttpServletRequest} attribute that contains the set of producible MediaTypes 
+	 * applicable to the mapped handler. 
+	 * <p>Note: This attribute is not required to be supported by all HandlerMapping implementations. 
+	 * Handlers should not necessarily expect this request attribute to be present in all scenarios.
+	 */
+	String PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE = HandlerMapping.class.getName() + ".producibleMediaTypes";
+
 	/**
 	 * Return a handler and any interceptors for this request. The choice may be made
 	 * on request URL, session state, or any factor the implementing class chooses.
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java
index c8611a31f8c..10eda4812f4 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java
@@ -25,6 +25,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 
@@ -173,11 +174,17 @@ public class RequestMappingHandlerMapping extends AbstractHandlerMethodMapping<R
 	}
 
 	@Override
-	protected void handleMatch(RequestMappingInfo mapping, String lookupPath, HttpServletRequest request) {
-		super.handleMatch(mapping, lookupPath, request);
-		String pattern = mapping.getPatterns().iterator().next();
+	protected void handleMatch(RequestMappingInfo info, String lookupPath, HttpServletRequest request) {
+		super.handleMatch(info, lookupPath, request);
+
+		String pattern = info.getPatterns().iterator().next();
 		Map<String, String> uriTemplateVariables = pathMatcher.extractUriTemplateVariables(pattern, lookupPath);
 		request.setAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, uriTemplateVariables);
+	
+		Set<MediaType> mediaTypes = info.getProduces().getMediaTypes();
+		if (mediaTypes.size() > 1 || !MediaType.ALL.equals(mediaTypes.iterator().next())) {
+			request.setAttribute(PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE, mediaTypes);
+		}
 	}
 
 	/**
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/AbstractMessageConverterMethodProcessor.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/AbstractMessageConverterMethodProcessor.java
index 127ad0ee696..4e714e6eb2f 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/AbstractMessageConverterMethodProcessor.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/AbstractMessageConverterMethodProcessor.java
@@ -17,18 +17,17 @@
 package org.springframework.web.servlet.mvc.method.annotation.support;
 
 import java.io.IOException;
-import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
@@ -37,12 +36,13 @@ import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.server.ServletServerHttpRequest;
 import org.springframework.http.server.ServletServerHttpResponse;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.web.HttpMediaTypeNotAcceptableException;
 import org.springframework.web.HttpMediaTypeNotSupportedException;
-import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
+import org.springframework.web.servlet.HandlerMapping;
 
 /**
  * A base class for resolving method argument values by reading from the body of a request with {@link
@@ -124,22 +124,43 @@ public abstract class AbstractMessageConverterMethodProcessor
 	 * @return the output message
 	 */
 	protected HttpOutputMessage createOutputMessage(NativeWebRequest webRequest) {
-		HttpServletResponse servletResponse = webRequest.getNativeResponse(HttpServletResponse.class);
-		return new ServletServerHttpResponse(servletResponse);
+		HttpServletResponse response = webRequest.getNativeResponse(HttpServletResponse.class);
+		return new ServletServerHttpResponse(response);
+	}
+
+	/**
+	 * Returns the media types that can be produced:
+	 * <ul>
+	 * 	<li>The set of producible media types specified in the request mappings, or
+	 * 	<li>The set of supported media types by all configured message converters, or
+	 * 	<li>{@link MediaType#ALL}
+	 */
+	@SuppressWarnings("unchecked")
+	protected Set<MediaType> getProducibleMediaTypes(NativeWebRequest webRequest) {
+		HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
+		Set<MediaType> mediaTypes = (Set<MediaType>) request.getAttribute(HandlerMapping.PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE);
+		if (!CollectionUtils.isEmpty(mediaTypes)) {
+			return mediaTypes;
+		}
+		else if (!allSupportedMediaTypes.isEmpty()) {
+			return new HashSet<MediaType>(allSupportedMediaTypes);
+		}
+		else {
+			return Collections.singleton(MediaType.ALL);
+		}
+			
 	}
 
 	@SuppressWarnings("unchecked")
 	protected <T> void writeWithMessageConverters(T returnValue,
 												  MethodParameter returnType,
 												  HttpInputMessage inputMessage,
-												  HttpOutputMessage outputMessage)
+												  HttpOutputMessage outputMessage,
+												  Set<MediaType> producibleMediaTypes)
 			throws IOException, HttpMediaTypeNotAcceptableException {
 
-		Set<MediaType> producibleMediaTypes = getProducibleMediaTypes(returnType.getMethod(), returnValue.getClass());
-		Set<MediaType> acceptableMediaTypes = getAcceptableMediaTypes(inputMessage);
-
 		List<MediaType> mediaTypes = new ArrayList<MediaType>();
-		for (MediaType acceptableMediaType : acceptableMediaTypes) {
+		for (MediaType acceptableMediaType : getAcceptableMediaTypes(inputMessage)) {
 			for (MediaType producibleMediaType : producibleMediaTypes) {
 				if (acceptableMediaType.isCompatibleWith(producibleMediaType)) {
 					mediaTypes.add(getMostSpecificMediaType(acceptableMediaType, producibleMediaType));
@@ -173,33 +194,7 @@ public abstract class AbstractMessageConverterMethodProcessor
 				}
 			}
 		}
-		else {
-			throw new HttpMediaTypeNotAcceptableException(allSupportedMediaTypes);
-		}
-	}
-
-	private Set<MediaType> getProducibleMediaTypes(Method handlerMethod, Class<?> returnValueClass) {
-		RequestMapping requestMappingAnn = handlerMethod.getAnnotation(RequestMapping.class);
-		if (requestMappingAnn == null) {
-			requestMappingAnn = handlerMethod.getClass().getAnnotation(RequestMapping.class);
-		}
-		Set<MediaType> result = new HashSet<MediaType>();
-		if (requestMappingAnn != null) {
-			for (String produce : requestMappingAnn.produces()) {
-				result.add(MediaType.parseMediaType(produce));
-			}
-		}
-		else {
-			for (HttpMessageConverter<?> messageConverter : messageConverters) {
-				if (messageConverter.canWrite(returnValueClass, null)) {
-					result.addAll(messageConverter.getSupportedMediaTypes());
-				}
-			}
-		}
-		if (result.isEmpty()) {
-			result.add(MediaType.ALL);
-		}
-		return result;
+		throw new HttpMediaTypeNotAcceptableException(allSupportedMediaTypes);
 	}
 
 	private Set<MediaType> getAcceptableMediaTypes(HttpInputMessage inputMessage) {
@@ -209,7 +204,7 @@ public abstract class AbstractMessageConverterMethodProcessor
 		}
 		return result;
 	}
-
+	
 	private MediaType getMostSpecificMediaType(MediaType type1, MediaType type2) {
 		return MediaType.SPECIFICITY_COMPARATOR.compare(type1, type2) < 0 ? type1 : type2;
 	}
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessor.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessor.java
index 31dd5a2f127..cd2864395d6 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessor.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessor.java
@@ -22,12 +22,14 @@ import java.lang.reflect.GenericArrayType;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.List;
+import java.util.Set;
 
 import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.server.ServerHttpResponse;
@@ -121,7 +123,8 @@ public class HttpEntityMethodProcessor extends AbstractMessageConverterMethodPro
 		
 		Object body = responseEntity.getBody();
 		if (body != null) {
-			writeWithMessageConverters(body, returnType, createInputMessage(webRequest), outputMessage);
+			Set<MediaType> mediaTypes = getProducibleMediaTypes(webRequest);
+			writeWithMessageConverters(body, returnType, createInputMessage(webRequest), outputMessage, mediaTypes);
 		}
 		else {
 			// flush headers to the HttpServletResponse
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessor.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessor.java
index 1d55a21472d..ebed2023603 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessor.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessor.java
@@ -18,10 +18,14 @@ package org.springframework.web.servlet.mvc.method.annotation.support;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Set;
+
 import javax.servlet.http.HttpServletResponse;
 
 import org.springframework.core.MethodParameter;
+import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
+import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.server.ServletServerHttpResponse;
 import org.springframework.web.HttpMediaTypeNotAcceptableException;
@@ -68,8 +72,10 @@ public class RequestResponseBodyMethodProcessor extends AbstractMessageConverter
 								  NativeWebRequest webRequest) throws IOException, HttpMediaTypeNotAcceptableException {
 		mavContainer.setResolveView(false);
 		if (returnValue != null) {
-			writeWithMessageConverters(returnValue, returnType, createInputMessage(webRequest),
-					createOutputMessage(webRequest));
+			HttpInputMessage inputMessage = createInputMessage(webRequest);
+			HttpOutputMessage outputMessage = createOutputMessage(webRequest);
+			Set<MediaType> mediaTypes = getProducibleMediaTypes(webRequest);
+			writeWithMessageConverters(returnValue, returnType, inputMessage, outputMessage, mediaTypes);
 		}
 	}
 
diff --git a/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessorTests.java b/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessorTests.java
index 28c9281931b..8aa4ac39084 100644
--- a/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessorTests.java
+++ b/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessorTests.java
@@ -15,6 +15,7 @@
  */
 
 package org.springframework.web.servlet.mvc.method.annotation.support;
+import static org.springframework.web.servlet.HandlerMapping.PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE;
 
 import java.lang.reflect.Method;
 import java.util.Arrays;
@@ -40,6 +41,7 @@ import org.springframework.web.HttpMediaTypeNotSupportedException;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.method.support.ModelAndViewContainer;
+import org.springframework.web.servlet.HandlerMapping;
 
 import static org.easymock.EasyMock.*;
 import static org.junit.Assert.*;
@@ -162,8 +164,6 @@ public class HttpEntityMethodProcessorTests {
 		MediaType accepted = MediaType.TEXT_PLAIN;
 		servletRequest.addHeader("Accept", accepted.toString());
 
-		expect(messageConverter.canWrite(String.class, null)).andReturn(true);
-		expect(messageConverter.getSupportedMediaTypes()).andReturn(Collections.singletonList(MediaType.TEXT_PLAIN));
 		expect(messageConverter.canWrite(String.class, accepted)).andReturn(true);
 		messageConverter.write(eq(body), eq(accepted), isA(HttpOutputMessage.class));
 		replay(messageConverter);
@@ -180,6 +180,7 @@ public class HttpEntityMethodProcessorTests {
 		ResponseEntity<String> returnValue = new ResponseEntity<String>(body, HttpStatus.OK);
 
 		servletRequest.addHeader("Accept", "text/*");
+		servletRequest.setAttribute(PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE, Collections.singleton(MediaType.TEXT_HTML));
 
 		expect(messageConverter.canWrite(String.class, MediaType.TEXT_HTML)).andReturn(true);
 		messageConverter.write(eq(body), eq(MediaType.TEXT_HTML), isA(HttpOutputMessage.class));
@@ -244,8 +245,6 @@ public class HttpEntityMethodProcessorTests {
 		ResponseEntity<String> returnValue = new ResponseEntity<String>("body", responseHeaders, HttpStatus.ACCEPTED);
 
 		Capture<HttpOutputMessage> outputMessage = new Capture<HttpOutputMessage>();
-		expect(messageConverter.canWrite(String.class, null)).andReturn(true);
-		expect(messageConverter.getSupportedMediaTypes()).andReturn(Arrays.asList(MediaType.TEXT_PLAIN));
 		expect(messageConverter.canWrite(String.class, MediaType.TEXT_PLAIN)).andReturn(true);
 		messageConverter.write(eq("body"), eq(MediaType.TEXT_PLAIN),  capture(outputMessage));
 		replay(messageConverter);
diff --git a/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessorTests.java b/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessorTests.java
index 6db478b9b5c..2c106155dd1 100644
--- a/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessorTests.java
+++ b/org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessorTests.java
@@ -38,6 +38,7 @@ import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.method.support.ModelAndViewContainer;
+import org.springframework.web.servlet.HandlerMapping;
 
 import static org.easymock.EasyMock.*;
 import static org.junit.Assert.*;
@@ -151,8 +152,6 @@ public class RequestResponseBodyMethodProcessorTests {
 		servletRequest.addHeader("Accept", accepted.toString());
 
 		String body = "Foo";
-		expect(messageConverter.canWrite(String.class, null)).andReturn(true);
-		expect(messageConverter.getSupportedMediaTypes()).andReturn(Collections.singletonList(MediaType.TEXT_PLAIN));
 		expect(messageConverter.canWrite(String.class, accepted)).andReturn(true);
 		messageConverter.write(eq(body), eq(accepted), isA(HttpOutputMessage.class));
 		replay(messageConverter);
@@ -168,6 +167,7 @@ public class RequestResponseBodyMethodProcessorTests {
 		String body = "Foo";
 
 		servletRequest.addHeader("Accept", "text/*");
+		servletRequest.setAttribute(HandlerMapping.PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE, Collections.singleton(MediaType.TEXT_HTML));
 
 		expect(messageConverter.canWrite(String.class, MediaType.TEXT_HTML)).andReturn(true);
 		messageConverter.write(eq(body), eq(MediaType.TEXT_HTML), isA(HttpOutputMessage.class));