Fix issue with @RequestBody args that are type vars

The change to support generic @RequestBody arguments introduced in
3.2 M2 also introduced a regression in reading arguments that are
type variables. This change fixes the issue.

Issue: SPR-9964

spring-web/src/main/java/org/springframework/http/converter/GenericHttpMessageConverter.java

@@ -27,6 +27,7 @@ import org.springframework.http.MediaType;
  * request into a target object of a specified generic type.
  *
  * @author Arjen Poutsma
+ * @author Rossen Stoyanchev
  * @since 3.2
  *
  * @see org.springframework.core.ParameterizedTypeReference
@@ -36,11 +37,13 @@ public interface GenericHttpMessageConverter<T> extends HttpMessageConverter<T>
 	/**
 	 * Indicates whether the given type can be read by this converter.
 	 * @param type the type to test for readability
+	 * @param contextClass a context class for the target type, for example a class
+	 * in which the target type appears in a method signature, can be {@code null}
 	 * @param mediaType the media type to read, can be {@code null} if not specified.
 	 * Typically the value of a {@code Content-Type} header.
 	 * @return {@code true} if readable; {@code false} otherwise
 	 */
-	boolean canRead(Type type, MediaType mediaType);
+	boolean canRead(Type type, Class<?> contextClass, MediaType mediaType);
 
 	/**
 	 * Read an object of the given type form the given input message, and returns it.
@@ -48,12 +51,14 @@ public interface GenericHttpMessageConverter<T> extends HttpMessageConverter<T>
 	 * been passed to the {@link #canRead canRead} method of this interface,
 	 * which must have returned {@code true}.
 	 * @param type the type of the target object
+	 * @param contextClass a context class for the target type, for example a class
+	 * in which the target type appears in a method signature, can be {@code null}
 	 * @param inputMessage the HTTP input message to read from
 	 * @return the converted object
 	 * @throws IOException in case of I/O errors
 	 * @throws HttpMessageNotReadableException in case of conversion errors
 	 */
-	T read(Type type, HttpInputMessage inputMessage)
+	T read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)
 			throws IOException, HttpMessageNotReadableException;
 
 }

spring-web/src/main/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverter.java

@@ -128,11 +128,11 @@ public class MappingJackson2HttpMessageConverter extends AbstractHttpMessageConv
 
 	@Override
 	public boolean canRead(Class<?> clazz, MediaType mediaType) {
-		return canRead((Type) clazz, mediaType);
+		return canRead((Type) clazz, null, mediaType);
 	}
 
-	public boolean canRead(Type type, MediaType mediaType) {
+	public boolean canRead(Type type, Class<?> contextClass, MediaType mediaType) {
-		JavaType javaType = getJavaType(type);
+		JavaType javaType = getJavaType(type, contextClass);
 		return (this.objectMapper.canDeserialize(javaType) && canRead(mediaType));
 	}
 
@@ -151,14 +151,14 @@ public class MappingJackson2HttpMessageConverter extends AbstractHttpMessageConv
 	protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage)
 			throws IOException, HttpMessageNotReadableException {
 
-		JavaType javaType = getJavaType(clazz);
+		JavaType javaType = getJavaType(clazz, null);
 		return readJavaType(javaType, inputMessage);
 	}
 
-	public Object read(Type type, HttpInputMessage inputMessage)
+	public Object read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)
 			throws IOException, HttpMessageNotReadableException {
 
-		JavaType javaType = getJavaType(type);
+		JavaType javaType = getJavaType(type, contextClass);
 		return readJavaType(javaType, inputMessage);
 	}
 
@@ -197,10 +197,10 @@ public class MappingJackson2HttpMessageConverter extends AbstractHttpMessageConv
 		}
 	}
 
-
 	/**
-	 * Return the Jackson {@link JavaType} for the specified type.
+	 * Return the Jackson {@link JavaType} for the specified type and context class.
-	 * <p>The default implementation returns {@link ObjectMapper#constructType(java.lang.reflect.Type)},
+	 * <p>The default implementation returns {@link ObjectMapper#constructType(java.lang.reflect.Type)}
+	 * or {@code ObjectMapper.getTypeFactory().constructType(type, contextClass)},
 	 * but this can be overridden in subclasses, to allow for custom generic collection handling.
 	 * For instance:
 	 * <pre class="code">
@@ -213,10 +213,15 @@ public class MappingJackson2HttpMessageConverter extends AbstractHttpMessageConv
 	 * }
 	 * </pre>
 	 * @param type the type to return the java type for
+	 * @param contextClass a context class for the target type, for example a class
+	 * in which the target type appears in a method signature, can be {@code null}
+	 * signature, can be {@code null}
 	 * @return the java type
 	 */
-	protected JavaType getJavaType(Type type) {
+	protected JavaType getJavaType(Type type, Class<?> contextClass) {
-		return this.objectMapper.constructType(type);
+		return (contextClass != null) ?
+			this.objectMapper.getTypeFactory().constructType(type, contextClass) :
+			this.objectMapper.constructType(type);
 	}
 
 	/**

spring-web/src/main/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverter.java

@@ -128,11 +128,11 @@ public class MappingJacksonHttpMessageConverter extends AbstractHttpMessageConve
 
 	@Override
 	public boolean canRead(Class<?> clazz, MediaType mediaType) {
-		return canRead((Type) clazz, mediaType);
+		return canRead((Type) clazz, null, mediaType);
 	}
 
-	public boolean canRead(Type type, MediaType mediaType) {
+	public boolean canRead(Type type, Class<?> contextClass, MediaType mediaType) {
-		JavaType javaType = getJavaType(type);
+		JavaType javaType = getJavaType(type, contextClass);
 		return (this.objectMapper.canDeserialize(javaType) && canRead(mediaType));
 	}
 
@@ -151,14 +151,14 @@ public class MappingJacksonHttpMessageConverter extends AbstractHttpMessageConve
 	protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage)
 			throws IOException, HttpMessageNotReadableException {
 
-		JavaType javaType = getJavaType(clazz);
+		JavaType javaType = getJavaType(clazz, null);
 		return readJavaType(javaType, inputMessage);
 	}
 
-	public Object read(Type type, HttpInputMessage inputMessage)
+	public Object read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)
 			throws IOException, HttpMessageNotReadableException {
 
-		JavaType javaType = getJavaType(type);
+		JavaType javaType = getJavaType(type, contextClass);
 		return readJavaType(javaType, inputMessage);
 	}
 
@@ -196,10 +196,10 @@ public class MappingJacksonHttpMessageConverter extends AbstractHttpMessageConve
 		}
 	}
 
-
 	/**
-	 * Return the Jackson {@link JavaType} for the specified type.
+	 * Return the Jackson {@link JavaType} for the specified type and context class.
-	 * <p>The default implementation returns {@link TypeFactory#type(java.lang.reflect.Type)},
+	 * <p>The default implementation returns {@link TypeFactory#type(java.lang.reflect.Type)}
+	 * or {@code TypeFactory.type(type, TypeFactory.type(contextClass))},
 	 * but this can be overridden in subclasses, to allow for custom generic collection handling.
 	 * For instance:
 	 * <pre class="code">
@@ -212,10 +212,14 @@ public class MappingJacksonHttpMessageConverter extends AbstractHttpMessageConve
 	 * }
 	 * </pre>
 	 * @param type the type to return the java type for
+	 * @param contextClass a context class for the target type, for example a class
+	 * in which the target type appears in a method signature, can be {@code null}
 	 * @return the java type
 	 */
-	protected JavaType getJavaType(Type type) {
+	protected JavaType getJavaType(Type type, Class<?> contextClass) {
-		return TypeFactory.type(type);
+		return (contextClass != null) ?
+			TypeFactory.type(type, TypeFactory.type(contextClass)) :
+			TypeFactory.type(type);
 	}
 
 	/**

spring-web/src/main/java/org/springframework/http/converter/xml/Jaxb2CollectionHttpMessageConverter.java

@@ -74,7 +74,7 @@ public class Jaxb2CollectionHttpMessageConverter<T extends Collection>
 	 * {@link Collection} where the generic type is a JAXB type annotated with
 	 * {@link XmlRootElement} or {@link XmlType}.
 	 */
-	public boolean canRead(Type type, MediaType mediaType) {
+	public boolean canRead(Type type, Class<?> contextClass, MediaType mediaType) {
 		if (!(type instanceof ParameterizedType)) {
 			return false;
 		}
@@ -119,7 +119,9 @@ public class Jaxb2CollectionHttpMessageConverter<T extends Collection>
 		throw new UnsupportedOperationException();
 	}
 
-	public T read(Type type, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException {
+	public T read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)
+			throws IOException, HttpMessageNotReadableException {
+
 		ParameterizedType parameterizedType = (ParameterizedType) type;
 		T result = createCollection((Class<?>) parameterizedType.getRawType());
 		Class<?> elementClass = (Class<?>) parameterizedType.getActualTypeArguments()[0];

spring-web/src/main/java/org/springframework/web/client/HttpMessageConverterExtractor.java

@@ -86,12 +86,12 @@ public class HttpMessageConverterExtractor<T> implements ResponseExtractor<T> {
 		for (HttpMessageConverter messageConverter : this.messageConverters) {
 			if (messageConverter instanceof GenericHttpMessageConverter) {
 				GenericHttpMessageConverter genericMessageConverter = (GenericHttpMessageConverter) messageConverter;
-				if (genericMessageConverter.canRead(this.responseType, contentType)) {
+				if (genericMessageConverter.canRead(this.responseType, null, contentType)) {
 					if (logger.isDebugEnabled()) {
 						logger.debug("Reading [" + this.responseType + "] as \"" +
 								contentType + "\" using [" + messageConverter + "]");
 					}
-					return (T) genericMessageConverter.read(this.responseType, response);
+					return (T) genericMessageConverter.read(this.responseType, null, response);
 				}
 			}
 			if (this.responseClass != null) {

spring-web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -553,20 +553,17 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 				}
 
 				List<MediaType> allSupportedMediaTypes = new ArrayList<MediaType>();
-				for (HttpMessageConverter<?> messageConverter : getMessageConverters()) {
+				for (HttpMessageConverter<?> converter : getMessageConverters()) {
 					if (responseClass != null) {
-						if (messageConverter.canRead(responseClass, null)) {
+						if (converter.canRead(responseClass, null)) {
-							allSupportedMediaTypes
+							allSupportedMediaTypes.addAll(getSupportedMediaTypes(converter));
-									.addAll(getSupportedMediaTypes(messageConverter));
 						}
 					}
-					else if (messageConverter instanceof GenericHttpMessageConverter) {
+					else if (converter instanceof GenericHttpMessageConverter) {
 
-						GenericHttpMessageConverter genericMessageConverter =
+						GenericHttpMessageConverter genericConverter = (GenericHttpMessageConverter) converter;
-								(GenericHttpMessageConverter) messageConverter;
+						if (genericConverter.canRead(responseType, null, null)) {
-						if (genericMessageConverter.canRead(responseType, null)) {
+							allSupportedMediaTypes.addAll(getSupportedMediaTypes(converter));
-							allSupportedMediaTypes
-									.addAll(getSupportedMediaTypes(messageConverter));
 						}
 					}
 

spring-web/src/test/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverterTests.java

@@ -51,12 +51,12 @@ public class MappingJackson2HttpMessageConverterTests extends AbstractMappingJac
 		MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter() {
 
 			@Override
-			protected JavaType getJavaType(Type type) {
+			protected JavaType getJavaType(Type type, Class<?> contextClass) {
 				if (type instanceof Class && List.class.isAssignableFrom((Class<?>)type)) {
 					return new ObjectMapper().getTypeFactory().constructCollectionType(ArrayList.class, MyBean.class);
 				}
 				else {
-					return super.getJavaType(type);
+					return super.getJavaType(type, contextClass);
 				}
 			}
 		};
@@ -87,7 +87,7 @@ public class MappingJackson2HttpMessageConverterTests extends AbstractMappingJac
 		inputMessage.getHeaders().setContentType(new MediaType("application", "json"));
 
 		MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
-		List<MyBean> results = (List<MyBean>) converter.read(beansList.getType(), inputMessage);
+		List<MyBean> results = (List<MyBean>) converter.read(beansList.getType(), null, inputMessage);
 		assertEquals(1, results.size());
 		MyBean result = results.get(0);
 		assertEquals("Foo", result.getString());

spring-web/src/test/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverterTests.java

@@ -49,12 +49,12 @@ public class MappingJacksonHttpMessageConverterTests extends AbstractMappingJack
 	public void readGenerics() throws IOException {
 		MappingJacksonHttpMessageConverter converter = new MappingJacksonHttpMessageConverter() {
 			@Override
-			protected JavaType getJavaType(Type type) {
+			protected JavaType getJavaType(Type type, Class<?> contextClass) {
 				if (type instanceof Class && List.class.isAssignableFrom((Class<?>)type)) {
 					return TypeFactory.collectionType(ArrayList.class, MyBean.class);
 				}
 				else {
-					return super.getJavaType(type);
+					return super.getJavaType(type, contextClass);
 				}
 			}
 		};
@@ -85,7 +85,7 @@ public class MappingJacksonHttpMessageConverterTests extends AbstractMappingJack
 		inputMessage.getHeaders().setContentType(new MediaType("application", "json"));
 
 		MappingJacksonHttpMessageConverter converter = new MappingJacksonHttpMessageConverter();
-		List<MyBean> results = (List<MyBean>) converter.read(beansList.getType(), inputMessage);
+		List<MyBean> results = (List<MyBean>) converter.read(beansList.getType(), null, inputMessage);
 		assertEquals(1, results.size());
 		MyBean result = results.get(0);
 		assertEquals("Foo", result.getString());

spring-web/src/test/java/org/springframework/http/converter/xml/Jaxb2CollectionHttpMessageConverterTests.java

@@ -63,9 +63,9 @@ public class Jaxb2CollectionHttpMessageConverterTests {
 
 	@Test
 	public void canRead() throws Exception {
-		assertTrue(converter.canRead(rootElementListType, null));
+		assertTrue(converter.canRead(rootElementListType, null, null));
-		assertTrue(converter.canRead(rootElementSetType, null));
+		assertTrue(converter.canRead(rootElementSetType, null, null));
-		assertTrue(converter.canRead(typeSetType, null));
+		assertTrue(converter.canRead(typeSetType, null, null));
 	}
 
 	@Test
@@ -74,7 +74,7 @@ public class Jaxb2CollectionHttpMessageConverterTests {
 		String content = "<list><rootElement><type s=\"1\"/></rootElement><rootElement><type s=\"2\"/></rootElement></list>";
 		MockHttpInputMessage inputMessage = new MockHttpInputMessage(content.getBytes("UTF-8"));
 
-		List<RootElement> result = (List<RootElement>) converter.read(rootElementListType, inputMessage);
+		List<RootElement> result = (List<RootElement>) converter.read(rootElementListType, null, inputMessage);
 
 		assertEquals("Invalid result", 2, result.size());
 		assertEquals("Invalid result", "1", result.get(0).type.s);
@@ -87,7 +87,7 @@ public class Jaxb2CollectionHttpMessageConverterTests {
 		String content = "<set><rootElement><type s=\"1\"/></rootElement><rootElement><type s=\"2\"/></rootElement></set>";
 		MockHttpInputMessage inputMessage = new MockHttpInputMessage(content.getBytes("UTF-8"));
 
-		Set<RootElement> result = (Set<RootElement>) converter.read(rootElementSetType, inputMessage);
+		Set<RootElement> result = (Set<RootElement>) converter.read(rootElementSetType, null, inputMessage);
 
 		assertEquals("Invalid result", 2, result.size());
 		assertTrue("Invalid result", result.contains(new RootElement("1")));
@@ -100,7 +100,7 @@ public class Jaxb2CollectionHttpMessageConverterTests {
 		String content = "<list><foo s=\"1\"/><bar s=\"2\"/></list>";
 		MockHttpInputMessage inputMessage = new MockHttpInputMessage(content.getBytes("UTF-8"));
 
-		List<TestType> result = (List<TestType>) converter.read(typeListType, inputMessage);
+		List<TestType> result = (List<TestType>) converter.read(typeListType, null, inputMessage);
 
 		assertEquals("Invalid result", 2, result.size());
 		assertEquals("Invalid result", "1", result.get(0).s);
@@ -113,7 +113,7 @@ public class Jaxb2CollectionHttpMessageConverterTests {
 		String content = "<set><foo s=\"1\"/><bar s=\"2\"/></set>";
 		MockHttpInputMessage inputMessage = new MockHttpInputMessage(content.getBytes("UTF-8"));
 
-		Set<TestType> result = (Set<TestType>) converter.read(typeSetType, inputMessage);
+		Set<TestType> result = (Set<TestType>) converter.read(typeSetType, null, inputMessage);
 
 		assertEquals("Invalid result", 2, result.size());
 		assertTrue("Invalid result", result.contains(new TestType("1")));

spring-web/src/test/java/org/springframework/web/client/HttpMessageConverterExtractorTests.java

@@ -176,8 +176,8 @@ public class HttpMessageConverterExtractorTests {
 
 		expect(response.getStatusCode()).andReturn(HttpStatus.OK);
 		expect(response.getHeaders()).andReturn(responseHeaders).times(2);
-		expect(converter.canRead(type, contentType)).andReturn(true);
+		expect(converter.canRead(type, null, contentType)).andReturn(true);
-		expect(converter.read(type, response)).andReturn(expected);
+		expect(converter.read(type, null, response)).andReturn(expected);
 
 		replay(response, converter);
 		Object result = extractor.extractData(response);

spring-web/src/test/java/org/springframework/web/client/RestTemplateTests.java

@@ -86,7 +86,7 @@ public class RestTemplateTests {
 
 		verifyMocks();
 	}
-	
+
 	@Test
 	public void varArgsNullTemplateVariable() throws Exception {
 		expect(requestFactory.createRequest(new URI("http://example.com/-foo"), HttpMethod.GET))
@@ -481,7 +481,7 @@ public class RestTemplateTests {
 
 		verifyMocks();
 	}
-	
+
 	@Test
 	public void postForEntityNull() throws Exception {
 		MediaType textPlain = new MediaType("text", "plain");
@@ -644,7 +644,7 @@ public class RestTemplateTests {
 		template.setMessageConverters(Collections.<HttpMessageConverter<?>>singletonList(converter));
 
 		ParameterizedTypeReference<List<Integer>> intList = new ParameterizedTypeReference<List<Integer>>() {};
-		expect(converter.canRead(intList.getType(), null)).andReturn(true);
+		expect(converter.canRead(intList.getType(), null, null)).andReturn(true);
 		expect(converter.getSupportedMediaTypes()).andReturn(Collections.singletonList(MediaType.TEXT_PLAIN));
 		expect(requestFactory.createRequest(new URI("http://example.com"), HttpMethod.POST)).andReturn(this.request);
 		HttpHeaders requestHeaders = new HttpHeaders();
@@ -660,8 +660,8 @@ public class RestTemplateTests {
 		expect(response.getStatusCode()).andReturn(HttpStatus.OK);
 		expect(response.getHeaders()).andReturn(responseHeaders).times(3);
 		List<Integer> expected = Collections.singletonList(42);
-		expect(converter.canRead(intList.getType(), MediaType.TEXT_PLAIN)).andReturn(true);
+		expect(converter.canRead(intList.getType(), null, MediaType.TEXT_PLAIN)).andReturn(true);
-		expect(converter.read(intList.getType(), response)).andReturn(expected);
+		expect(converter.read(intList.getType(), null, response)).andReturn(expected);
 		expect(response.getStatusCode()).andReturn(HttpStatus.OK);
 		response.close();
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/AbstractMessageConverterMethodArgumentResolver.java

@@ -21,16 +21,19 @@ import java.lang.reflect.Array;
 import java.lang.reflect.GenericArrayType;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import javax.servlet.http.HttpServletRequest;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.MediaType;
@@ -104,40 +107,44 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 	 * @param <T> the expected type of the argument value to be created
 	 * @param inputMessage the HTTP input message representing the current request
 	 * @param methodParam the method argument
-	 * @param paramType the type of the argument value to be created
+	 * @param targetType the type of object to create, not necessarily the same as
+	 * the method parameter type (e.g. for {@code HttpEntity<String>} method
+	 * parameter the target type is String)
 	 * @return the created method argument value
 	 * @throws IOException if the reading from the request fails
 	 * @throws HttpMediaTypeNotSupportedException if no suitable message converter is found
 	 */
 	@SuppressWarnings("unchecked")
 	protected <T> Object readWithMessageConverters(HttpInputMessage inputMessage,
-			MethodParameter methodParam, Type paramType) throws IOException, HttpMediaTypeNotSupportedException {
+			MethodParameter methodParam, Type targetType) throws IOException, HttpMediaTypeNotSupportedException {
 
 				MediaType contentType = inputMessage.getHeaders().getContentType();
 				if (contentType == null) {
 					contentType = MediaType.APPLICATION_OCTET_STREAM;
 				}
 
-				Class<T> paramClass = getParamClass(paramType);
+				Class<?> contextClass = methodParam.getDeclaringClass();
+				Map<TypeVariable, Type> map = GenericTypeResolver.getTypeVariableMap(contextClass);
+				Class<T> targetClass = (Class<T>) GenericTypeResolver.resolveType(targetType, map);
 
-				for (HttpMessageConverter<?> messageConverter : this.messageConverters) {
+				for (HttpMessageConverter<?> converter : this.messageConverters) {
-					if (messageConverter instanceof GenericHttpMessageConverter) {
+					if (converter instanceof GenericHttpMessageConverter) {
-						GenericHttpMessageConverter genericMessageConverter = (GenericHttpMessageConverter) messageConverter;
+						GenericHttpMessageConverter genericConverter = (GenericHttpMessageConverter) converter;
-						if (genericMessageConverter.canRead(paramType, contentType)) {
+						if (genericConverter.canRead(targetType, contextClass, contentType)) {
 							if (logger.isDebugEnabled()) {
-								logger.debug("Reading [" + paramType + "] as \"" +
+								logger.debug("Reading [" + targetType + "] as \"" +
-										contentType + "\" using [" + messageConverter + "]");
+										contentType + "\" using [" + converter + "]");
 							}
-							return (T) genericMessageConverter.read(paramType, inputMessage);
+							return (T) genericConverter.read(targetType, contextClass, inputMessage);
 						}
 					}
-					if (paramClass != null) {
+					if (targetClass != null) {
-						if (messageConverter.canRead(paramClass, contentType)) {
+						if (converter.canRead(targetClass, contentType)) {
 							if (logger.isDebugEnabled()) {
-								logger.debug("Reading [" + paramClass.getName() + "] as \"" + contentType + "\" using [" +
+								logger.debug("Reading [" + targetClass.getName() + "] as \"" +
-										messageConverter + "]");
+										contentType + "\" using [" + converter + "]");
 							}
-							return ((HttpMessageConverter<T>) messageConverter).read(paramClass, inputMessage);
+							return ((HttpMessageConverter<T>) converter).read(targetClass, inputMessage);
 						}
 					}
 				}
@@ -145,26 +152,6 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 				throw new HttpMediaTypeNotSupportedException(contentType, allSupportedMediaTypes);
 			}
 
-	private Class getParamClass(Type paramType) {
-		if (paramType instanceof Class) {
-			return (Class) paramType;
-		}
-		else if (paramType instanceof GenericArrayType) {
-			Type componentType = ((GenericArrayType) paramType).getGenericComponentType();
-			if (componentType instanceof Class) {
-				// Surely, there should be a nicer way to determine the array type
-				return Array.newInstance((Class<?>) componentType, 0).getClass();
-			}
-		}
-		else if (paramType instanceof ParameterizedType) {
-			ParameterizedType parameterizedType = (ParameterizedType) paramType;
-			if (parameterizedType.getRawType() instanceof Class) {
-				return (Class) parameterizedType.getRawType();
-			}
-		}
-		return null;
-	}
-
 	/**
 	 * Creates a new {@link HttpInputMessage} from the given {@link NativeWebRequest}.
 	 *

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/HttpEntityMethodProcessorTests.java

@@ -18,6 +18,7 @@ package org.springframework.web.servlet.mvc.method.annotation;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
+import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
@@ -26,6 +27,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpEntity;
+import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.mock.web.MockHttpServletRequest;
@@ -35,6 +37,7 @@ import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.bind.support.WebDataBinderFactory;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.method.support.ModelAndViewContainer;
 
 /**
@@ -58,6 +61,8 @@ public class HttpEntityMethodProcessorTests {
 
 	private MockHttpServletRequest servletRequest;
 
+	private WebDataBinderFactory binderFactory;
+
 	@Before
 	public void setUp() throws Exception {
 
@@ -70,6 +75,8 @@ public class HttpEntityMethodProcessorTests {
 		servletRequest = new MockHttpServletRequest();
 		servletResponse = new MockHttpServletResponse();
 		webRequest = new ServletWebRequest(servletRequest, servletResponse);
+
+		binderFactory = new ValidatingBinderFactory();
 	}
 
 	@Test
@@ -84,7 +91,7 @@ public class HttpEntityMethodProcessorTests {
 
 		@SuppressWarnings("unchecked")
 		HttpEntity<SimpleBean> result = (HttpEntity<SimpleBean>) processor.resolveArgument(
-				paramSimpleBean, mavContainer, webRequest, new ValidatingBinderFactory());
+				paramSimpleBean, mavContainer, webRequest, binderFactory);
 
 		assertNotNull(result);
 		assertEquals("Jad", result.getBody().getName());
@@ -102,27 +109,68 @@ public class HttpEntityMethodProcessorTests {
 
 		@SuppressWarnings("unchecked")
 		HttpEntity<List<SimpleBean>> result = (HttpEntity<List<SimpleBean>>) processor.resolveArgument(
-				paramList, mavContainer, webRequest, new ValidatingBinderFactory());
+				paramList, mavContainer, webRequest, binderFactory);
 
 		assertNotNull(result);
 		assertEquals("Jad", result.getBody().get(0).getName());
 		assertEquals("Robert", result.getBody().get(1).getName());
 	}
 
+	@Test
+	public void resolveArgumentTypeVariable() throws Exception {
+
+		Method method = MySimpleParameterizedController.class.getMethod("handleDto", HttpEntity.class);
+		HandlerMethod handlerMethod = new HandlerMethod(new MySimpleParameterizedController(), method);
+		MethodParameter methodParam = handlerMethod.getMethodParameters()[0];
+
+		String content = "{\"name\" : \"Jad\"}";
+		this.servletRequest.setContent(content.getBytes("UTF-8"));
+		this.servletRequest.setContentType(MediaType.APPLICATION_JSON_VALUE);
+
+		List<HttpMessageConverter<?>> converters = new ArrayList<HttpMessageConverter<?>>();
+		converters.add(new MappingJackson2HttpMessageConverter());
+		HttpEntityMethodProcessor processor = new HttpEntityMethodProcessor(converters);
+
+		@SuppressWarnings("unchecked")
+		HttpEntity<SimpleBean> result = (HttpEntity<SimpleBean>) processor.resolveArgument(methodParam, mavContainer, webRequest, binderFactory);
+
+		assertNotNull(result);
+		assertEquals("Jad", result.getBody().getName());
+	}
 
 	public void handle(HttpEntity<List<SimpleBean>> arg1, HttpEntity<SimpleBean> arg2) {
 	}
 
+	private static abstract class MyParameterizedController<DTO extends Identifiable> {
+		@SuppressWarnings("unused")
+		public void handleDto(HttpEntity<DTO> dto) {}
+	}
 
-	private static class SimpleBean {
+	private static class MySimpleParameterizedController extends MyParameterizedController<SimpleBean> { }
 
+	private interface Identifiable extends Serializable {
+		public Long getId();
+		public void setId(Long id);
+	}
+
+	@SuppressWarnings({ "serial" })
+	private static class SimpleBean implements Identifiable {
+
+		private Long id;
 		private String name;
 
+		public Long getId() {
+			return id;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
 		public String getName() {
 			return name;
 		}
 
-		@SuppressWarnings("unused")
 		public void setName(String name) {
 			this.name = name;
 		}

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestResponseBodyMethodProcessorTests.java

@@ -19,9 +19,9 @@ package org.springframework.web.servlet.mvc.method.annotation;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
+import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 
 import org.junit.Before;
@@ -42,6 +42,7 @@ import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.support.WebDataBinderFactory;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.method.support.ModelAndViewContainer;
 
 /**
@@ -68,6 +69,9 @@ public class RequestResponseBodyMethodProcessorTests {
 
 	private MockHttpServletResponse servletResponse;
 
+	private ValidatingBinderFactory binderFactory;
+
+
 	@Before
 	public void setUp() throws Exception {
 
@@ -85,8 +89,9 @@ public class RequestResponseBodyMethodProcessorTests {
 		servletRequest = new MockHttpServletRequest();
 		servletResponse = new MockHttpServletResponse();
 		webRequest = new ServletWebRequest(servletRequest, servletResponse);
-	}
 
+		this.binderFactory = new ValidatingBinderFactory();
+	}
 
 	@Test
 	public void resolveArgumentParameterizedType() throws Exception {
@@ -100,7 +105,7 @@ public class RequestResponseBodyMethodProcessorTests {
 
 		@SuppressWarnings("unchecked")
 		List<SimpleBean> result = (List<SimpleBean>) processor.resolveArgument(
-				paramGenericList, mavContainer, webRequest, new ValidatingBinderFactory());
+				paramGenericList, mavContainer, webRequest, binderFactory);
 
 		assertNotNull(result);
 		assertEquals("Jad", result.get(0).getName());
@@ -119,7 +124,7 @@ public class RequestResponseBodyMethodProcessorTests {
 
 		@SuppressWarnings("unchecked")
 		MultiValueMap<String, String> result = (MultiValueMap<String, String>) processor.resolveArgument(
-				paramMultiValueMap, mavContainer, webRequest, new ValidatingBinderFactory());
+				paramMultiValueMap, mavContainer, webRequest, binderFactory);
 
 		assertNotNull(result);
 		assertEquals("apple", result.getFirst("fruit"));
@@ -137,7 +142,7 @@ public class RequestResponseBodyMethodProcessorTests {
 		RequestResponseBodyMethodProcessor processor = new RequestResponseBodyMethodProcessor(converters);
 
 		SimpleBean result = (SimpleBean) processor.resolveArgument(
-				paramSimpleBean, mavContainer, webRequest, new ValidatingBinderFactory());
+				paramSimpleBean, mavContainer, webRequest, binderFactory);
 
 		assertNotNull(result);
 		assertEquals("Jad", result.getName());
@@ -154,12 +159,35 @@ public class RequestResponseBodyMethodProcessorTests {
 		RequestResponseBodyMethodProcessor processor = new RequestResponseBodyMethodProcessor(converters);
 
 		String result = (String) processor.resolveArgument(
-				paramString, mavContainer, webRequest, new ValidatingBinderFactory());
+				paramString, mavContainer, webRequest, binderFactory);
 
 		assertNotNull(result);
 		assertEquals("foobarbaz", result);
 	}
 
+	// SPR-9964
+
+	@Test
+	public void resolveArgumentTypeVariable() throws Exception {
+
+		Method method = MySimpleParameterizedController.class.getMethod("handleDto", Identifiable.class);
+		HandlerMethod handlerMethod = new HandlerMethod(new MySimpleParameterizedController(), method);
+		MethodParameter methodParam = handlerMethod.getMethodParameters()[0];
+
+		String content = "{\"name\" : \"Jad\"}";
+		this.servletRequest.setContent(content.getBytes("UTF-8"));
+		this.servletRequest.setContentType(MediaType.APPLICATION_JSON_VALUE);
+
+		List<HttpMessageConverter<?>> converters = new ArrayList<HttpMessageConverter<?>>();
+		converters.add(new MappingJackson2HttpMessageConverter());
+		RequestResponseBodyMethodProcessor processor = new RequestResponseBodyMethodProcessor(converters);
+
+		SimpleBean result = (SimpleBean) processor.resolveArgument(methodParam, mavContainer, webRequest, binderFactory);
+
+		assertNotNull(result);
+		assertEquals("Jad", result.getName());
+	}
+
 	// SPR-9160
 
 	@Test
@@ -213,15 +241,36 @@ public class RequestResponseBodyMethodProcessorTests {
 		return null;
 	}
 
-	private static class SimpleBean {
+	private static abstract class MyParameterizedController<DTO extends Identifiable> {
+		@SuppressWarnings("unused")
+		public void handleDto(@RequestBody DTO dto) {}
+	}
 
+	private static class MySimpleParameterizedController extends MyParameterizedController<SimpleBean> { }
+
+	private interface Identifiable extends Serializable {
+		public Long getId();
+		public void setId(Long id);
+	}
+
+	@SuppressWarnings({ "serial" })
+	private static class SimpleBean implements Identifiable {
+
+		private Long id;
 		private String name;
 
+		public Long getId() {
+			return id;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
 		public String getName() {
 			return name;
 		}
 
-		@SuppressWarnings("unused")
 		public void setName(String name) {
 			this.name = name;
 		}