Improve empty request body handling

The check for an empty request body InputStream is now in the base
class AbstractMessageConverterMethodArgumentResolver shared for
all arguments that involve reading with an HttpMessageConverter --
@RequestBody, @RequestPart, and HttpEntity.

When an empty body is detected any configured RequestBodyAdvice is
given a chance to select a default value or leave it as null.

Issue: SPR-12778, SPR-12860, SPR-12861

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

@@ -17,6 +17,8 @@
 package org.springframework.web.servlet.mvc.method.annotation;
 
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.PushbackInputStream;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
@@ -33,6 +35,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.InvalidMediaTypeException;
 import org.springframework.http.MediaType;
@@ -57,6 +60,9 @@ import org.springframework.web.method.support.HandlerMethodArgumentResolver;
  */
 public abstract class AbstractMessageConverterMethodArgumentResolver implements HandlerMethodArgumentResolver {
 
+	private static final Object NO_VALUE = new Object();
+
+
 	protected final Log logger = LogFactory.getLog(getClass());
 
 	protected final List<HttpMessageConverter<?>> messageConverters;
@@ -135,9 +141,8 @@ 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 param the method parameter descriptor (may be {@code null})
-	 * @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)
+	 * @param targetType the target type, not necessarily the same as the method
+	 * parameter type, e.g. for {@code HttpEntity<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
@@ -165,6 +170,9 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 			targetClass = (Class<T>) resolvableType.resolve();
 		}
 
+		inputMessage = new EmptyBodyCheckingHttpInputMessage(inputMessage);
+		Object body = NO_VALUE;
+
 		for (HttpMessageConverter<?> converter : this.messageConverters) {
 			Class<HttpMessageConverter<?>> converterType = (Class<HttpMessageConverter<?>>) converter.getClass();
 			if (converter instanceof GenericHttpMessageConverter) {
@@ -173,9 +181,16 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 					if (logger.isDebugEnabled()) {
 						logger.debug("Read [" + targetType + "] as \"" + contentType + "\" with [" + converter + "]");
 					}
-					inputMessage = getAdvice().beforeBodyRead(inputMessage, param, targetType, converterType);
-					T body = (T) genericConverter.read(targetType, contextClass, inputMessage);
-					return getAdvice().afterBodyRead(body, inputMessage, param, targetType, converterType);
+					if (inputMessage.getBody() != null) {
+						inputMessage = getAdvice().beforeBodyRead(inputMessage, param, targetType, converterType);
+						body = genericConverter.read(targetType, contextClass, inputMessage);
+						body = getAdvice().afterBodyRead(body, inputMessage, param, targetType, converterType);
+					}
+					else {
+						body = null;
+						body = getAdvice().handleEmptyBody(body, inputMessage, param, targetType, converterType);
+					}
+					break;
 				}
 			}
 			else if (targetClass != null) {
@@ -183,14 +198,25 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 					if (logger.isDebugEnabled()) {
 						logger.debug("Read [" + targetType + "] as \"" + contentType + "\" with [" + converter + "]");
 					}
-					inputMessage = getAdvice().beforeBodyRead(inputMessage, param, targetType, converterType);
-					T body = ((HttpMessageConverter<T>) converter).read(targetClass, inputMessage);
-					return getAdvice().afterBodyRead(body, inputMessage, param, targetType, converterType);
+					if (inputMessage.getBody() != null) {
+						inputMessage = getAdvice().beforeBodyRead(inputMessage, param, targetType, converterType);
+						body = ((HttpMessageConverter<T>) converter).read(targetClass, inputMessage);
+						body = getAdvice().afterBodyRead(body, inputMessage, param, targetType, converterType);
+					}
+					else {
+						body = null;
+						body = getAdvice().handleEmptyBody(body, inputMessage, param, targetType, converterType);
+					}
+					break;
 				}
 			}
 		}
 
-		throw new HttpMediaTypeNotSupportedException(contentType, this.allSupportedMediaTypes);
+		if (body == NO_VALUE) {
+			throw new HttpMediaTypeNotSupportedException(contentType, this.allSupportedMediaTypes);
+		}
+
+		return body;
 	}
 
 	/**
@@ -240,4 +266,47 @@ public abstract class AbstractMessageConverterMethodArgumentResolver implements
 		return !hasBindingResult;
 	}
 
+
+	private static class EmptyBodyCheckingHttpInputMessage implements HttpInputMessage {
+
+		private final HttpHeaders headers;
+
+		private final InputStream body;
+
+
+		public EmptyBodyCheckingHttpInputMessage(HttpInputMessage inputMessage) throws IOException {
+			this.headers = inputMessage.getHeaders();
+			InputStream inputStream = inputMessage.getBody();
+			if (inputStream == null) {
+				this.body = null;
+			}
+			else if (inputStream.markSupported()) {
+				inputStream.mark(1);
+				this.body = (inputStream.read() != -1 ? inputStream : null);
+				inputStream.reset();
+			}
+			else {
+				PushbackInputStream pushbackInputStream = new PushbackInputStream(inputStream);
+				int b = pushbackInputStream.read();
+				if (b == -1) {
+					this.body = null;
+				}
+				else {
+					this.body = pushbackInputStream;
+					pushbackInputStream.unread(b);
+				}
+			}
+		}
+
+		@Override
+		public HttpHeaders getHeaders() {
+			return this.headers;
+		}
+
+		@Override
+		public InputStream getBody() throws IOException {
+			return this.body;
+		}
+	}
+
 }

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

@@ -19,12 +19,14 @@ package org.springframework.web.servlet.mvc.method.annotation;
 import java.io.IOException;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
+import java.net.URI;
 import java.util.List;
 
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ResolvableType;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.RequestEntity;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -120,8 +122,9 @@ public class HttpEntityMethodProcessor extends AbstractMessageConverterMethodPro
 
 		Object body = readWithMessageConverters(webRequest, parameter, paramType);
 		if (RequestEntity.class.equals(parameter.getParameterType())) {
-			return new RequestEntity<Object>(body, inputMessage.getHeaders(),
-					inputMessage.getMethod(), inputMessage.getURI());
+			URI url = inputMessage.getURI();
+			HttpMethod httpMethod = inputMessage.getMethod();
+			return new RequestEntity<Object>(body, inputMessage.getHeaders(), httpMethod, url);
 		}
 		else {
 			return new HttpEntity<Object>(body, inputMessage.getHeaders());

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

@@ -17,8 +17,6 @@
 package org.springframework.web.servlet.mvc.method.annotation;
 
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.PushbackInputStream;
 import java.lang.reflect.Type;
 import java.util.List;
 
@@ -146,43 +144,14 @@ public class RequestResponseBodyMethodProcessor extends AbstractMessageConverter
 		HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);
 		HttpInputMessage inputMessage = new ServletServerHttpRequest(servletRequest);
 
-		InputStream inputStream = inputMessage.getBody();
-		if (inputStream == null) {
-			return handleEmptyBody(methodParam);
-		}
-		else if (inputStream.markSupported()) {
-			inputStream.mark(1);
-			if (inputStream.read() == -1) {
-				return handleEmptyBody(methodParam);
-			}
-			inputStream.reset();
-		}
-		else {
-			final PushbackInputStream pushbackInputStream = new PushbackInputStream(inputStream);
-			int b = pushbackInputStream.read();
-			if (b == -1) {
-				return handleEmptyBody(methodParam);
-			}
-			else {
-				pushbackInputStream.unread(b);
+		Object arg = readWithMessageConverters(inputMessage, methodParam, paramType);
+		if (arg == null) {
+			if (methodParam.getParameterAnnotation(RequestBody.class).required()) {
+				throw new HttpMessageNotReadableException("Required request body is missing: " + methodParam);
 			}
-			inputMessage = new ServletServerHttpRequest(servletRequest) {
-				@Override
-				public InputStream getBody() {
-					// Form POST should not get here
-					return pushbackInputStream;
-				}
-			};
 		}
 
-		return super.readWithMessageConverters(inputMessage, methodParam, paramType);
-	}
-
-	private Object handleEmptyBody(MethodParameter param) {
-		if (param.getParameterAnnotation(RequestBody.class).required()) {
-			throw new HttpMessageNotReadableException("Required request body content is missing: " + param);
-		}
-		return null;
+		return arg;
 	}
 
 	@Override

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

@@ -16,14 +16,19 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
+import static org.junit.Assert.*;
+import static org.mockito.BDDMockito.any;
+import static org.mockito.BDDMockito.*;
+import static org.mockito.BDDMockito.isA;
+import static org.mockito.Matchers.eq;
+import static org.springframework.web.servlet.HandlerMapping.*;
+
 import java.lang.reflect.Method;
 import java.net.URI;
-import java.text.SimpleDateFormat;
+import java.nio.charset.Charset;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
-import java.util.Locale;
-import java.util.TimeZone;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -48,13 +53,6 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.method.support.ModelAndViewContainer;
 
-import static org.junit.Assert.*;
-import static org.mockito.BDDMockito.any;
-import static org.mockito.BDDMockito.*;
-import static org.mockito.BDDMockito.isA;
-import static org.mockito.Matchers.eq;
-import static org.springframework.web.servlet.HandlerMapping.*;
-
 /**
  * Test fixture for {@link HttpEntityMethodProcessor} delegating to a mock
  * {@link HttpMessageConverter}.
@@ -136,10 +134,12 @@ public class HttpEntityMethodProcessorMockTests {
 
 	@Test
 	public void resolveArgument() throws Exception {
+		String body = "Foo";
+
 		MediaType contentType = MediaType.TEXT_PLAIN;
 		servletRequest.addHeader("Content-Type", contentType.toString());
+		servletRequest.setContent(body.getBytes(Charset.forName("UTF-8")));
 
-		String body = "Foo";
 		given(messageConverter.canRead(String.class, contentType)).willReturn(true);
 		given(messageConverter.read(eq(String.class), isA(HttpInputMessage.class))).willReturn(body);
 
@@ -152,14 +152,16 @@ public class HttpEntityMethodProcessorMockTests {
 
 	@Test
 	public void resolveArgumentRequestEntity() throws Exception {
+		String body = "Foo";
+
 		MediaType contentType = MediaType.TEXT_PLAIN;
 		servletRequest.addHeader("Content-Type", contentType.toString());
 		servletRequest.setMethod("GET");
 		servletRequest.setServerName("www.example.com");
 		servletRequest.setServerPort(80);
 		servletRequest.setRequestURI("/path");
+		servletRequest.setContent(body.getBytes(Charset.forName("UTF-8")));
 
-		String body = "Foo";
 		given(messageConverter.canRead(String.class, contentType)).willReturn(true);
 		given(messageConverter.read(eq(String.class), isA(HttpInputMessage.class))).willReturn(body);
 
@@ -226,6 +228,7 @@ public class HttpEntityMethodProcessorMockTests {
 		verify(messageConverter).write(eq(body), eq(MediaType.TEXT_HTML), isA(HttpOutputMessage.class));
 	}
 
+	@SuppressWarnings("unchecked")
 	@Test
 	public void handleReturnValueWithResponseBodyAdvice() throws Exception {
 		ResponseEntity<String> returnValue = new ResponseEntity<>(HttpStatus.OK);
@@ -416,28 +419,35 @@ public class HttpEntityMethodProcessorMockTests {
 		assertEquals(0, servletResponse.getContentAsByteArray().length);
 	}
 
-	public ResponseEntity<String> handle1(HttpEntity<String> httpEntity, ResponseEntity<String> responseEntity, int i, RequestEntity<String> requestEntity) {
-		return responseEntity;
+	@SuppressWarnings("unused")
+	public ResponseEntity<String> handle1(HttpEntity<String> httpEntity, ResponseEntity<String> entity,
+			int i, RequestEntity<String> requestEntity) {
+
+		return entity;
 	}
 
+	@SuppressWarnings("unused")
 	public HttpEntity<?> handle2(HttpEntity<?> entity) {
 		return entity;
 	}
 
+	@SuppressWarnings("unused")
 	public CustomHttpEntity handle2x(HttpEntity<?> entity) {
 		return new CustomHttpEntity();
 	}
 
+	@SuppressWarnings("unused")
 	public int handle3() {
 		return 42;
 	}
 
+	@SuppressWarnings("unused")
 	@RequestMapping(produces = {"text/html", "application/xhtml+xml"})
 	public ResponseEntity<String> handle4() {
 		return null;
 	}
 
-
+	@SuppressWarnings("unused")
 	public static class CustomHttpEntity extends HttpEntity<Object> {
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,9 +16,12 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
+import static org.junit.Assert.*;
+
 import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 import org.junit.Before;
@@ -39,8 +42,6 @@ import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.method.support.ModelAndViewContainer;
 
-import static org.junit.Assert.*;
-
 /**
  * Test fixture with {@link HttpEntityMethodProcessor} delegating to
  * actual {@link HttpMessageConverter} instances.
@@ -61,8 +62,6 @@ public class HttpEntityMethodProcessorTests {
 
 	private MockHttpServletRequest servletRequest;
 
-	private MockHttpServletResponse servletResponse;
-
 	private ServletWebRequest webRequest;
 
 
@@ -75,8 +74,7 @@ public class HttpEntityMethodProcessorTests {
 		mavContainer = new ModelAndViewContainer();
 		binderFactory = new ValidatingBinderFactory();
 		servletRequest = new MockHttpServletRequest();
-		servletResponse = new MockHttpServletResponse();
-		webRequest = new ServletWebRequest(servletRequest, servletResponse);
+		webRequest = new ServletWebRequest(servletRequest, new MockHttpServletResponse());
 	}
 
 	@Test
@@ -97,6 +95,23 @@ public class HttpEntityMethodProcessorTests {
 		assertEquals("Jad", result.getBody().getName());
 	}
 
+	// SPR-12861
+
+	@Test
+	public void resolveArgumentWithEmptyBody() throws Exception {
+		this.servletRequest.setContent(new byte[0]);
+		this.servletRequest.setContentType("application/json");
+
+		List<HttpMessageConverter<?>> converters = Arrays.asList(new MappingJackson2HttpMessageConverter());
+		HttpEntityMethodProcessor processor = new HttpEntityMethodProcessor(converters);
+
+		HttpEntity<?> result = (HttpEntity<?>) processor.resolveArgument(this.paramSimpleBean,
+				this.mavContainer, this.webRequest, this.binderFactory);
+
+		assertNotNull(result);
+		assertNull(result.getBody());
+	}
+
 	@Test
 	public void resolveGenericArgument() throws Exception {
 		String content = "[{\"name\" : \"Jad\"}, {\"name\" : \"Robert\"}]";
@@ -139,21 +154,21 @@ public class HttpEntityMethodProcessorTests {
 	}
 
 
+	@SuppressWarnings("unused")
 	public void handle(HttpEntity<List<SimpleBean>> arg1, HttpEntity<SimpleBean> arg2) {
 	}
 
-
+	@SuppressWarnings("unused")
 	private static abstract class MyParameterizedController<DTO extends Identifiable> {
 
 		public void handleDto(HttpEntity<DTO> dto) {
 		}
 	}
 
-
+	@SuppressWarnings("unused")
 	private static class MySimpleParameterizedController extends MyParameterizedController<SimpleBean> {
 	}
 
-
 	private interface Identifiable extends Serializable {
 
 		public Long getId();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,13 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
+import static org.junit.Assert.*;
+
 import java.net.URI;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
+
 import javax.servlet.MultipartConfigElement;
 
 import org.eclipse.jetty.server.Server;
@@ -34,8 +39,10 @@ import org.springframework.core.io.ClassPathResource;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
+import org.springframework.http.converter.ByteArrayHttpMessageConverter;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.ResourceHttpMessageConverter;
 import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
@@ -57,8 +64,6 @@ import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
-import static org.junit.Assert.*;
-
 /**
  * Test access to parts of a multipart request with {@link RequestPart}.
  *
@@ -102,9 +107,16 @@ public class RequestPartIntegrationTests {
 
 	@Before
 	public void setUp() {
+		ByteArrayHttpMessageConverter emptyBodyConverter = new ByteArrayHttpMessageConverter();
+		emptyBodyConverter.setSupportedMediaTypes(Arrays.asList(MediaType.APPLICATION_JSON));
+
+		List<HttpMessageConverter<?>> converters = new ArrayList<>(3);
+		converters.add(emptyBodyConverter);
+		converters.add(new ResourceHttpMessageConverter());
+		converters.add(new MappingJackson2HttpMessageConverter());
+
 		AllEncompassingFormHttpMessageConverter converter = new AllEncompassingFormHttpMessageConverter();
-		converter.setPartConverters(Arrays.<HttpMessageConverter<?>>asList(
-				new ResourceHttpMessageConverter(), new MappingJackson2HttpMessageConverter()));
+		converter.setPartConverters(converters);
 
 		restTemplate = new RestTemplate(new HttpComponentsClientHttpRequestFactory());
 		restTemplate.setMessageConverters(Arrays.<HttpMessageConverter<?>>asList(converter));
@@ -130,9 +142,9 @@ public class RequestPartIntegrationTests {
 
 	private void testCreate(String url) {
 		MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
-		HttpEntity<TestData> jsonEntity = new HttpEntity<TestData>(new TestData("Jason"));
-		parts.add("json-data", jsonEntity);
+		parts.add("json-data", new HttpEntity<TestData>(new TestData("Jason")));
 		parts.add("file-data", new ClassPathResource("logo.jpg", this.getClass()));
+		parts.add("empty-data", new HttpEntity<byte[]>(new byte[0])); // SPR-12860
 
 		URI location = restTemplate.postForLocation(url, parts);
 		assertEquals("http://localhost:8080/test/Jason/logo.jpg", location.toString());
@@ -167,11 +179,15 @@ public class RequestPartIntegrationTests {
 		}
 	}
 
+	@SuppressWarnings("unused")
 	@Controller
 	private static class RequestPartTestController {
 
 		@RequestMapping(value = "/test", method = RequestMethod.POST, consumes = { "multipart/mixed", "multipart/form-data" })
-		public ResponseEntity<Object> create(@RequestPart("json-data") TestData testData, @RequestPart("file-data") MultipartFile file) {
+		public ResponseEntity<Object> create(@RequestPart("json-data") TestData testData,
+				@RequestPart("file-data") MultipartFile file,
+				@RequestPart(value = "empty-data", required = false) TestData emptyData) {
+
 			String url = "http://localhost:8080/test/" + testData.getName() + "/" + file.getOriginalFilename();
 			HttpHeaders headers = new HttpHeaders();
 			headers.setLocation(URI.create(url));

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

@@ -16,11 +16,16 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
+import static org.junit.Assert.*;
+import static org.mockito.BDDMockito.*;
+
 import java.lang.reflect.Method;
+import java.nio.charset.Charset;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
+
 import javax.servlet.http.Part;
 import javax.validation.Valid;
 import javax.validation.constraints.NotNull;
@@ -31,6 +36,7 @@ import org.junit.Test;
 
 import org.springframework.core.LocalVariableTableParameterNameDiscoverer;
 import org.springframework.core.MethodParameter;
+import org.springframework.http.HttpInputMessage;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.mock.web.test.MockHttpServletRequest;
@@ -52,9 +58,6 @@ import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.multipart.support.MissingServletRequestPartException;
 import org.springframework.web.multipart.support.RequestPartServletServerHttpRequest;
 
-import static org.junit.Assert.*;
-import static org.mockito.BDDMockito.*;
-
 /**
  * Test fixture with {@link RequestPartMethodArgumentResolver} and mock {@link HttpMessageConverter}.
  *
@@ -90,8 +93,6 @@ public class RequestPartMethodArgumentResolverTests {
 
 	private MockMultipartHttpServletRequest multipartRequest;
 
-	private MockHttpServletResponse servletResponse;
-
 
 	@SuppressWarnings("unchecked")
 	@Before
@@ -128,13 +129,14 @@ public class RequestPartMethodArgumentResolverTests {
 		resolver = new RequestPartMethodArgumentResolver(Collections.<HttpMessageConverter<?>>singletonList(messageConverter));
 		reset(messageConverter);
 
-		multipartFile1 = new MockMultipartFile("requestPart", "", "text/plain", (byte[]) null);
-		multipartFile2 = new MockMultipartFile("requestPart", "", "text/plain", (byte[]) null);
+		byte[] content = "doesn't matter as long as not empty".getBytes(Charset.forName("UTF-8"));
+
+		multipartFile1 = new MockMultipartFile("requestPart", "", "text/plain", content);
+		multipartFile2 = new MockMultipartFile("requestPart", "", "text/plain", content);
 		multipartRequest = new MockMultipartHttpServletRequest();
 		multipartRequest.addFile(multipartFile1);
 		multipartRequest.addFile(multipartFile2);
-		servletResponse = new MockHttpServletResponse();
-		webRequest = new ServletWebRequest(multipartRequest, servletResponse);
+		webRequest = new ServletWebRequest(multipartRequest, new MockHttpServletResponse());
 	}
 
 
@@ -361,7 +363,7 @@ public class RequestPartMethodArgumentResolverTests {
 		SimpleBean simpleBean = new SimpleBean("foo");
 
 		given(messageConverter.canRead(SimpleBean.class, MediaType.TEXT_PLAIN)).willReturn(true);
-		given(messageConverter.read(eq(SimpleBean.class), isA(RequestPartServletServerHttpRequest.class))).willReturn(simpleBean);
+		given(messageConverter.read(eq(SimpleBean.class), isA(HttpInputMessage.class))).willReturn(simpleBean);
 
 		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
 		Object actualValue = resolver.resolveArgument(optionalRequestPart, mavContainer, webRequest, new ValidatingBinderFactory());
@@ -385,7 +387,7 @@ public class RequestPartMethodArgumentResolverTests {
 
 	private void testResolveArgument(SimpleBean argValue, MethodParameter parameter) throws Exception {
 		given(messageConverter.canRead(SimpleBean.class, MediaType.TEXT_PLAIN)).willReturn(true);
-		given(messageConverter.read(eq(SimpleBean.class), isA(RequestPartServletServerHttpRequest.class))).willReturn(argValue);
+		given(messageConverter.read(eq(SimpleBean.class), isA(HttpInputMessage.class))).willReturn(argValue);
 
 		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
 		Object actualValue = resolver.resolveArgument(parameter, mavContainer, webRequest, new ValidatingBinderFactory());
@@ -423,7 +425,7 @@ public class RequestPartMethodArgumentResolverTests {
 		}
 	}
 
-
+	@SuppressWarnings("unused")
 	public void handle(@RequestPart SimpleBean requestPart,
 					   @RequestPart(value="requestPart", required=false) SimpleBean namedRequestPart,
 					   @Valid @RequestPart("requestPart") SimpleBean validRequestPart,

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

@@ -16,12 +16,15 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
-import java.io.IOException;
+import static org.junit.Assert.*;
+import static org.mockito.BDDMockito.*;
+
 import java.lang.reflect.Method;
 import java.nio.charset.Charset;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+
 import javax.validation.Valid;
 import javax.validation.constraints.NotNull;
 
@@ -49,9 +52,6 @@ import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.method.support.ModelAndViewContainer;
 import org.springframework.web.servlet.HandlerMapping;
 
-import static org.junit.Assert.*;
-import static org.mockito.BDDMockito.*;
-
 /**
  * Test fixture for {@link RequestResponseBodyMethodProcessor} delegating to a
  * mock HttpMessageConverter.
@@ -81,7 +81,6 @@ public class RequestResponseBodyMethodProcessorMockTests {
 
 	private MockHttpServletRequest servletRequest;
 
-	private MockHttpServletResponse servletResponse;
 
 	@SuppressWarnings("unchecked")
 	@Before
@@ -103,8 +102,7 @@ public class RequestResponseBodyMethodProcessorMockTests {
 		mavContainer = new ModelAndViewContainer();
 
 		servletRequest = new MockHttpServletRequest();
-		servletResponse = new MockHttpServletResponse();
-		webRequest = new ServletWebRequest(servletRequest, servletResponse);
+		webRequest = new ServletWebRequest(servletRequest, new MockHttpServletResponse());
 	}
 
 	@Test
@@ -154,7 +152,7 @@ public class RequestResponseBodyMethodProcessorMockTests {
 		testResolveArgumentWithValidation(new SimpleBean("name"));
 	}
 
-	private void testResolveArgumentWithValidation(SimpleBean simpleBean) throws IOException, Exception {
+	private void testResolveArgumentWithValidation(SimpleBean simpleBean) throws Exception {
 		MediaType contentType = MediaType.TEXT_PLAIN;
 		servletRequest.addHeader("Content-Type", contentType.toString());
 		servletRequest.setContent("payload".getBytes(Charset.forName("UTF-8")));
@@ -189,6 +187,7 @@ public class RequestResponseBodyMethodProcessorMockTests {
 			fail("Expected exception");
 		}
 		catch (HttpMediaTypeNotSupportedException ex) {
+			// expected
 		}
 	}
 
@@ -212,7 +211,9 @@ public class RequestResponseBodyMethodProcessorMockTests {
 
 	@Test
 	public void resolveArgumentNotRequiredNoContent() throws Exception {
+		servletRequest.setContentType("text/plain");
 		servletRequest.setContent(new byte[0]);
+		given(messageConverter.canRead(String.class, MediaType.TEXT_PLAIN)).willReturn(true);
 		assertNull(processor.resolveArgument(paramStringNotRequired, mavContainer, webRequest, new ValidatingBinderFactory()));
 	}
 
@@ -293,23 +294,28 @@ public class RequestResponseBodyMethodProcessorMockTests {
 	}
 
 
+	@SuppressWarnings("unused")
 	@ResponseBody
 	public String handle1(@RequestBody String s, int i) {
 		return s;
 	}
 
+	@SuppressWarnings("unused")
 	public int handle2() {
 		return 42;
 	}
 
+	@SuppressWarnings("unused")
 	@ResponseBody
 	public String handle3() {
 		return null;
 	}
 
+	@SuppressWarnings("unused")
 	public void handle4(@Valid @RequestBody SimpleBean b) {
 	}
 
+	@SuppressWarnings("unused")
 	public void handle5(@RequestBody(required=false) String s) {
 	}
 

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

@@ -18,6 +18,7 @@ package org.springframework.web.servlet.mvc.method.annotation;
 
 import java.io.Serializable;
 import java.lang.reflect.Method;
+import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -29,6 +30,7 @@ import org.junit.Test;
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.aop.target.SingletonTargetSource;
 import org.springframework.core.MethodParameter;
+import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -177,7 +179,9 @@ public class RequestResponseBodyMethodProcessorTests {
 		assertEquals("foobarbaz", result);
 	}
 
-	@Test(expected = HttpMessageNotReadableException.class)  // SPR-9942
+	// SPR-9942
+
+	@Test(expected = HttpMessageNotReadableException.class)
 	public void resolveArgumentRequiredNoContent() throws Exception {
 		this.servletRequest.setContent(new byte[0]);
 		this.servletRequest.setContentType("text/plain");
@@ -187,7 +191,23 @@ public class RequestResponseBodyMethodProcessorTests {
 		processor.resolveArgument(paramString, mavContainer, webRequest, binderFactory);
 	}
 
-	@Test  // SPR-9964
+	// SPR-12778
+
+	@Test
+	public void resolveArgumentRequiredNoContentDefaultValue() throws Exception {
+		this.servletRequest.setContent(new byte[0]);
+		this.servletRequest.setContentType("text/plain");
+		List<HttpMessageConverter<?>> converters = Arrays.asList(new StringHttpMessageConverter());
+		List<Object> advice = Arrays.asList(new EmptyRequestBodyAdvice());
+		RequestResponseBodyMethodProcessor processor = new RequestResponseBodyMethodProcessor(converters, advice);
+		String arg = (String) processor.resolveArgument(paramString, mavContainer, webRequest, binderFactory);
+		assertNotNull(arg);
+		assertEquals("default value for empty body", arg);
+	}
+
+	// SPR-9964
+
+	@Test
 	public void resolveArgumentTypeVariable() throws Exception {
 		Method method = MyParameterizedController.class.getMethod("handleDto", Identifiable.class);
 		HandlerMethod handlerMethod = new HandlerMethod(new MySimpleParameterizedController(), method);
@@ -207,7 +227,9 @@ public class RequestResponseBodyMethodProcessorTests {
 		assertEquals("Jad", result.getName());
 	}
 
-	@Test  // SPR-11225
+	// SPR-11225
+
+	@Test
 	public void resolveArgumentTypeVariableWithNonGenericConverter() throws Exception {
 		Method method = MyParameterizedController.class.getMethod("handleDto", Identifiable.class);
 		HandlerMethod handlerMethod = new HandlerMethod(new MySimpleParameterizedController(), method);
@@ -229,7 +251,9 @@ public class RequestResponseBodyMethodProcessorTests {
 		assertEquals("Jad", result.getName());
 	}
 
-	@Test  // SPR-9160
+	// SPR-9160
+
+	@Test
 	public void handleReturnValueSortByQuality() throws Exception {
 		this.servletRequest.addHeader("Accept", "text/plain; q=0.5, application/json");
 
@@ -383,6 +407,7 @@ public class RequestResponseBodyMethodProcessorTests {
 	}
 
 
+	@SuppressWarnings("unused")
 	public String handle(
 			@RequestBody List<SimpleBean> list,
 			@RequestBody SimpleBean simpleBean,
@@ -393,6 +418,7 @@ public class RequestResponseBodyMethodProcessorTests {
 	}
 
 
+	@SuppressWarnings("unused")
 	private static abstract class MyParameterizedController<DTO extends Identifiable> {
 
 		@SuppressWarnings("unused")
@@ -400,6 +426,7 @@ public class RequestResponseBodyMethodProcessorTests {
 	}
 
 
+	@SuppressWarnings("unused")
 	private static class MySimpleParameterizedController extends MyParameterizedController<SimpleBean> {
 	}
 
@@ -472,9 +499,10 @@ public class RequestResponseBodyMethodProcessorTests {
 		}
 	}
 
-	private interface MyJacksonView1 {};
-	private interface MyJacksonView2 {};
+	private interface MyJacksonView1 {}
+	private interface MyJacksonView2 {}
 
+	@SuppressWarnings("unused")
 	private static class JacksonViewBean {
 
 		@JsonView(MyJacksonView1.class)
@@ -537,4 +565,35 @@ public class RequestResponseBodyMethodProcessorTests {
 
 	}
 
+	private static class EmptyRequestBodyAdvice implements RequestBodyAdvice {
+
+		@Override
+		public boolean supports(MethodParameter methodParameter, Type targetType,
+				Class<? extends HttpMessageConverter<?>> converterType) {
+
+			return StringHttpMessageConverter.class.equals(converterType);
+		}
+
+		@Override
+		public Object handleEmptyBody(Object body, HttpInputMessage inputMessage, MethodParameter parameter,
+				Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
+
+			return "default value for empty body";
+		}
+
+		@Override
+		public HttpInputMessage beforeBodyRead(HttpInputMessage inputMessage, MethodParameter parameter,
+				Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
+
+			return inputMessage;
+		}
+
+		@Override
+		public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter,
+				Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
+
+			return body;
+		}
+	}
+
 }