Consistent java.util.Optional resolution, lenient handling of optional multipart files, correct Servlet 3.0 Part list/array selection

Issue: SPR-13418
Issue: SPR-13849
Issue: SPR-13850
Issue: SPR-13893

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -48,12 +48,13 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 		super(null);
 	}
 
+
 	@Override
 	public boolean supportsParameter(MethodParameter parameter) {
 		if (!parameter.hasParameterAnnotation(MatrixVariable.class)) {
 			return false;
 		}
-		if (Map.class.isAssignableFrom(parameter.getParameterType())) {
+		if (Map.class.isAssignableFrom(parameter.nestedIfOptional().getNestedParameterType())) {
 			String variableName = parameter.getParameterAnnotation(MatrixVariable.class).name();
 			return StringUtils.hasText(variableName);
 		}
@@ -67,13 +68,10 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 	}
 
 	@Override
+	@SuppressWarnings("unchecked")
 	protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request) throws Exception {
-
-		@SuppressWarnings("unchecked")
-		Map<String, MultiValueMap<String, String>> pathParameters =
-			(Map<String, MultiValueMap<String, String>>) request.getAttribute(
-					HandlerMapping.MATRIX_VARIABLES_ATTRIBUTE, RequestAttributes.SCOPE_REQUEST);
-
+		Map<String, MultiValueMap<String, String>> pathParameters = (Map<String, MultiValueMap<String, String>>)
+				request.getAttribute(HandlerMapping.MATRIX_VARIABLES_ATTRIBUTE, RequestAttributes.SCOPE_REQUEST);
 		if (CollectionUtils.isEmpty(pathParameters)) {
 			return null;
 		}
@@ -92,10 +90,10 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 			for (MultiValueMap<String, String> params : pathParameters.values()) {
 				if (params.containsKey(name)) {
 					if (found) {
-						String paramType = parameter.getParameterType().getName();
+						String paramType = parameter.getNestedParameterType().getName();
 						throw new ServletRequestBindingException(
 								"Found more than one match for URI path parameter '" + name +
-								"' for parameter type [" + paramType + "]. Use pathVar attribute to disambiguate.");
+								"' for parameter type [" + paramType + "]. Use 'pathVar' attribute to disambiguate.");
 					}
 					paramValues.addAll(params.get(name));
 					found = true;
@@ -117,7 +115,7 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 	@Override
 	protected void handleMissingValue(String name, MethodParameter parameter) throws ServletRequestBindingException {
 		throw new ServletRequestBindingException("Missing matrix variable '" + name +
-				"' for method parameter of type " + parameter.getParameterType().getSimpleName());
+				"' for method parameter of type " + parameter.getNestedParameterType().getSimpleName());
 	}
 
 
@@ -127,4 +125,5 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 			super(annotation.name(), annotation.required(), annotation.defaultValue());
 		}
 	}
-}
+
+}

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

@@ -79,7 +79,7 @@ public class PathVariableMethodArgumentResolver extends AbstractNamedValueMethod
 		if (!parameter.hasParameterAnnotation(PathVariable.class)) {
 			return false;
 		}
-		if (Map.class.isAssignableFrom(parameter.getParameterType())) {
+		if (Map.class.isAssignableFrom(parameter.nestedIfOptional().getNestedParameterType())) {
 			String paramName = parameter.getParameterAnnotation(PathVariable.class).value();
 			return StringUtils.hasText(paramName);
 		}
@@ -95,10 +95,9 @@ public class PathVariableMethodArgumentResolver extends AbstractNamedValueMethod
 	@Override
 	@SuppressWarnings("unchecked")
 	protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request) throws Exception {
-		Map<String, String> uriTemplateVars =
-			(Map<String, String>) request.getAttribute(
-					HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, RequestAttributes.SCOPE_REQUEST);
-		return (uriTemplateVars != null) ? uriTemplateVars.get(name) : null;
+		Map<String, String> uriTemplateVars = (Map<String, String>) request.getAttribute(
+				HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, RequestAttributes.SCOPE_REQUEST);
+		return (uriTemplateVars != null ? uriTemplateVars.get(name) : null);
 	}
 
 	@Override
@@ -127,7 +126,7 @@ public class PathVariableMethodArgumentResolver extends AbstractNamedValueMethod
 	public void contributeMethodArgument(MethodParameter parameter, Object value,
 			UriComponentsBuilder builder, Map<String, Object> uriVariables, ConversionService conversionService) {
 
-		if (Map.class.isAssignableFrom(parameter.getParameterType())) {
+		if (Map.class.isAssignableFrom(parameter.getNestedParameterType())) {
 			return;
 		}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -16,20 +16,15 @@
 
 package org.springframework.web.servlet.mvc.method.annotation;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
-
 import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.Part;
 
-import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.lang.UsesJava8;
-import org.springframework.util.Assert;
 import org.springframework.validation.BindingResult;
 import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.WebDataBinder;
@@ -41,12 +36,10 @@ import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.method.support.ModelAndViewContainer;
 import org.springframework.web.multipart.MultipartException;
 import org.springframework.web.multipart.MultipartFile;
-import org.springframework.web.multipart.MultipartHttpServletRequest;
 import org.springframework.web.multipart.MultipartResolver;
 import org.springframework.web.multipart.support.MissingServletRequestPartException;
+import org.springframework.web.multipart.support.MultipartResolutionDelegate;
 import org.springframework.web.multipart.support.RequestPartServletServerHttpRequest;
-import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;
-import org.springframework.web.util.WebUtils;
 
 /**
  * Resolves the following method arguments:
@@ -65,12 +58,13 @@ import org.springframework.web.util.WebUtils;
  * it is derived from the name of the method argument.
  *
  * <p>Automatic validation may be applied if the argument is annotated with
- * {@code @javax.validation.Valid}. In case of validation failure, a
- * {@link MethodArgumentNotValidException} is raised and a 400 response status
- * code returned if {@link DefaultHandlerExceptionResolver} is configured.
+ * {@code @javax.validation.Valid}. In case of validation failure, a {@link MethodArgumentNotValidException}
+ * is raised and a 400 response status code returned if
+ * {@link org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver} is configured.
  *
  * @author Rossen Stoyanchev
  * @author Brian Clozel
+ * @author Juergen Hoeller
  * @since 3.1
  */
 public class RequestPartMethodArgumentResolver extends AbstractMessageConverterMethodArgumentResolver {
@@ -107,18 +101,10 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 			return true;
 		}
 		else {
-			if (parameter.hasParameterAnnotation(RequestParam.class)){
-				return false;
-			}
-			else if (MultipartFile.class == parameter.getParameterType()) {
-				return true;
-			}
-			else if ("javax.servlet.http.Part".equals(parameter.getParameterType().getName())) {
-				return true;
-			}
-			else {
+			if (parameter.hasParameterAnnotation(RequestParam.class)) {
 				return false;
 			}
+			return MultipartResolutionDelegate.isMultipartArgument(parameter.nestedIfOptional());
 		}
 	}
 
@@ -128,87 +114,58 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 			NativeWebRequest request, WebDataBinderFactory binderFactory) throws Exception {
 
 		HttpServletRequest servletRequest = request.getNativeRequest(HttpServletRequest.class);
-		assertIsMultipartRequest(servletRequest);
+		RequestPart requestPart = parameter.getParameterAnnotation(RequestPart.class);
+		boolean isRequired = ((requestPart == null || requestPart.required()) && !parameter.isOptional());
 
-		MultipartHttpServletRequest multipartRequest =
-				WebUtils.getNativeRequest(servletRequest, MultipartHttpServletRequest.class);
+		String name = getPartName(parameter, requestPart);
+		parameter = parameter.nestedIfOptional();
+		Object arg = null;
 
-		Class<?> paramType = parameter.getParameterType();
-		boolean optional = paramType.getName().equals("java.util.Optional");
-		if (optional) {
-			parameter.increaseNestingLevel();
-			paramType = parameter.getNestedParameterType();
-		}
-
-		String partName = getPartName(parameter);
-		Object arg;
-
-		if (MultipartFile.class == paramType) {
-			Assert.notNull(multipartRequest, "Expected MultipartHttpServletRequest: is a MultipartResolver configured?");
-			arg = multipartRequest.getFile(partName);
-		}
-		else if (isMultipartFileCollection(parameter)) {
-			Assert.notNull(multipartRequest, "Expected MultipartHttpServletRequest: is a MultipartResolver configured?");
-			arg = multipartRequest.getFiles(partName);
-		}
-		else if (isMultipartFileArray(parameter)) {
-			Assert.notNull(multipartRequest, "Expected MultipartHttpServletRequest: is a MultipartResolver configured?");
-			List<MultipartFile> files = multipartRequest.getFiles(partName);
-			arg = files.toArray(new MultipartFile[files.size()]);
-		}
-		else if ("javax.servlet.http.Part".equals(paramType.getName())) {
-			assertIsMultipartRequest(servletRequest);
-			arg = servletRequest.getPart(partName);
-		}
-		else if (isPartCollection(parameter)) {
-			assertIsMultipartRequest(servletRequest);
-			arg = new ArrayList<Object>(servletRequest.getParts());
-		}
-		else if (isPartArray(parameter)) {
-			assertIsMultipartRequest(servletRequest);
-			arg = RequestPartResolver.resolvePart(servletRequest);
+		Object mpArg = MultipartResolutionDelegate.resolveMultipartArgument(name, parameter, servletRequest);
+		if (mpArg != MultipartResolutionDelegate.UNRESOLVABLE) {
+			arg = mpArg;
 		}
 		else {
 			try {
-				HttpInputMessage inputMessage = new RequestPartServletServerHttpRequest(servletRequest, partName);
+				HttpInputMessage inputMessage = new RequestPartServletServerHttpRequest(servletRequest, name);
 				arg = readWithMessageConverters(inputMessage, parameter, parameter.getNestedGenericParameterType());
-				WebDataBinder binder = binderFactory.createBinder(request, arg, partName);
+				WebDataBinder binder = binderFactory.createBinder(request, arg, name);
 				if (arg != null) {
 					validateIfApplicable(binder, parameter);
 					if (binder.getBindingResult().hasErrors() && isBindExceptionRequired(binder, parameter)) {
 						throw new MethodArgumentNotValidException(parameter, binder.getBindingResult());
 					}
 				}
-				mavContainer.addAttribute(BindingResult.MODEL_KEY_PREFIX + partName, binder.getBindingResult());
+				mavContainer.addAttribute(BindingResult.MODEL_KEY_PREFIX + name, binder.getBindingResult());
 			}
 			catch (MissingServletRequestPartException ex) {
-				// handled below
-				arg = null;
+				if (isRequired) {
+					throw ex;
+				}
+			}
+			catch (MultipartException ex) {
+				if (isRequired) {
+					throw ex;
+				}
 			}
 		}
 
-		RequestPart requestPart = parameter.getParameterAnnotation(RequestPart.class);
-		boolean isRequired = ((requestPart == null || requestPart.required()) && !optional);
-
 		if (arg == null && isRequired) {
-			throw new MissingServletRequestPartException(partName);
+			if (!MultipartResolutionDelegate.isMultipartRequest(servletRequest)) {
+				throw new MultipartException("Current request is not a multipart request");
+			}
+			else {
+				throw new MissingServletRequestPartException(name);
+			}
 		}
-		if (optional) {
-			arg = Optional.ofNullable(arg);
+		if (parameter.isOptional()) {
+			arg = OptionalResolver.resolveValue(arg);
 		}
 
 		return arg;
 	}
 
-	private static void assertIsMultipartRequest(HttpServletRequest request) {
-		String contentType = request.getContentType();
-		if (contentType == null || !contentType.toLowerCase().startsWith("multipart/")) {
-			throw new MultipartException("The current request is not a multipart request");
-		}
-	}
-
-	private String getPartName(MethodParameter methodParam) {
-		RequestPart requestPart = methodParam.getParameterAnnotation(RequestPart.class);
+	private String getPartName(MethodParameter methodParam, RequestPart requestPart) {
 		String partName = (requestPart != null ? requestPart.name() : "");
 		if (partName.length() == 0) {
 			partName = methodParam.getParameterName();
@@ -221,46 +178,18 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 		return partName;
 	}
 
-	private boolean isMultipartFileCollection(MethodParameter methodParam) {
-		Class<?> collectionType = getCollectionParameterType(methodParam);
-		return MultipartFile.class == collectionType;
-	}
-
-	private boolean isMultipartFileArray(MethodParameter methodParam) {
-		Class<?> paramType = methodParam.getNestedParameterType().getComponentType();
-		return MultipartFile.class == paramType;
-	}
-
-	private boolean isPartCollection(MethodParameter methodParam) {
-		Class<?> collectionType = getCollectionParameterType(methodParam);
-		return (collectionType != null && "javax.servlet.http.Part".equals(collectionType.getName()));
-	}
-
-	private boolean isPartArray(MethodParameter methodParam) {
-		Class<?> paramType = methodParam.getNestedParameterType().getComponentType();
-		return (paramType != null && "javax.servlet.http.Part".equals(paramType.getName()));
-	}
-
-	private Class<?> getCollectionParameterType(MethodParameter methodParam) {
-		Class<?> paramType = methodParam.getNestedParameterType();
-		if (Collection.class == paramType || List.class.isAssignableFrom(paramType)){
-			Class<?> valueType = GenericCollectionTypeResolver.getCollectionParameterType(methodParam);
-			if (valueType != null) {
-				return valueType;
-			}
-		}
-		return null;
-	}
-
 
 	/**
-	 * Inner class to avoid hard-coded dependency on Servlet 3.0 Part type...
+	 * Inner class to avoid hard-coded dependency on Java 8 Optional type...
 	 */
-	private static class RequestPartResolver {
+	private static class OptionalResolver {
 
-		public static Object resolvePart(HttpServletRequest servletRequest) throws Exception {
-			Collection<Part> parts = servletRequest.getParts();
-			return parts.toArray(new Part[parts.size()]);
+		public static Object resolveValue(Object value) {
+			if (value == null || (value instanceof Collection && ((Collection) value).isEmpty()) ||
+					(value instanceof Object[] && ((Object[]) value).length == 0)) {
+				return Optional.empty();
+			}
+			return Optional.of(value);
 		}
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -52,7 +52,7 @@ public class ServletCookieValueMethodArgumentResolver extends AbstractCookieValu
 	protected Object resolveName(String cookieName, MethodParameter parameter, NativeWebRequest webRequest) throws Exception {
 		HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);
 		Cookie cookieValue = WebUtils.getCookie(servletRequest, cookieName);
-		if (Cookie.class.isAssignableFrom(parameter.getParameterType())) {
+		if (Cookie.class.isAssignableFrom(parameter.getNestedParameterType())) {
 			return cookieValue;
 		}
 		else if (cookieValue != null) {

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

@@ -262,6 +262,12 @@ public class ServletInvocableHandlerMethod extends InvocableHandlerMethod {
 			this.returnType = ResolvableType.forType(super.getGenericParameterType()).getGeneric(0);
 		}
 
+		public ConcurrentResultMethodParameter(ConcurrentResultMethodParameter original) {
+			super(original);
+			this.returnValue = original.returnValue;
+			this.returnType = original.returnType;
+		}
+
 		@Override
 		public Class<?> getParameterType() {
 			if (this.returnValue != null) {
@@ -283,6 +289,11 @@ public class ServletInvocableHandlerMethod extends InvocableHandlerMethod {
 		public Type getGenericParameterType() {
 			return this.returnType.getType();
 		}
+
+		@Override
+		public ConcurrentResultMethodParameter clone() {
+			return new ConcurrentResultMethodParameter(this);
+		}
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -41,6 +41,7 @@ import org.springframework.mock.web.test.MockHttpServletResponse;
 import org.springframework.mock.web.test.MockMultipartFile;
 import org.springframework.mock.web.test.MockMultipartHttpServletRequest;
 import org.springframework.mock.web.test.MockPart;
+import org.springframework.util.ReflectionUtils;
 import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.WebDataBinder;
@@ -53,7 +54,6 @@ import org.springframework.web.method.support.ModelAndViewContainer;
 import org.springframework.web.multipart.MultipartException;
 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.*;
@@ -86,7 +86,9 @@ public class RequestPartMethodArgumentResolverTests {
 	private MethodParameter paramPartArray;
 	private MethodParameter paramRequestParamAnnot;
 	private MethodParameter optionalMultipartFile;
+	private MethodParameter optionalMultipartFileList;
 	private MethodParameter optionalPart;
+	private MethodParameter optionalPartList;
 	private MethodParameter optionalRequestPart;
 
 	private NativeWebRequest webRequest;
@@ -97,10 +99,7 @@ public class RequestPartMethodArgumentResolverTests {
 	@SuppressWarnings("unchecked")
 	@Before
 	public void setUp() throws Exception {
-		Method method = getClass().getMethod("handle", SimpleBean.class, SimpleBean.class,
-				SimpleBean.class, MultipartFile.class, List.class, MultipartFile[].class,
-				Integer.TYPE, MultipartFile.class, Part.class, List.class, Part[].class,
-				MultipartFile.class, Optional.class, Optional.class, Optional.class);
+		Method method = ReflectionUtils.findMethod(getClass(), "handle", (Class<?>[]) null);
 
 		paramRequestPart = new SynthesizingMethodParameter(method, 0);
 		paramRequestPart.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
@@ -119,9 +118,13 @@ public class RequestPartMethodArgumentResolverTests {
 		paramRequestParamAnnot = new SynthesizingMethodParameter(method, 11);
 		optionalMultipartFile = new SynthesizingMethodParameter(method, 12);
 		optionalMultipartFile.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
-		optionalPart = new SynthesizingMethodParameter(method, 13);
+		optionalMultipartFileList = new SynthesizingMethodParameter(method, 13);
+		optionalMultipartFileList.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
+		optionalPart = new SynthesizingMethodParameter(method, 14);
 		optionalPart.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
-		optionalRequestPart = new SynthesizingMethodParameter(method, 14);
+		optionalPartList = new SynthesizingMethodParameter(method, 15);
+		optionalPartList.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
+		optionalRequestPart = new SynthesizingMethodParameter(method, 16);
 
 		messageConverter = mock(HttpMessageConverter.class);
 		given(messageConverter.getSupportedMediaTypes()).willReturn(Collections.singletonList(MediaType.TEXT_PLAIN));
@@ -136,35 +139,41 @@ public class RequestPartMethodArgumentResolverTests {
 		multipartRequest = new MockMultipartHttpServletRequest();
 		multipartRequest.addFile(multipartFile1);
 		multipartRequest.addFile(multipartFile2);
+		multipartRequest.addFile(new MockMultipartFile("otherPart", "", "text/plain", content));
 		webRequest = new ServletWebRequest(multipartRequest, new MockHttpServletResponse());
 	}
 
 
 	@Test
 	public void supportsParameter() {
-		assertTrue("RequestPart parameter not supported", resolver.supportsParameter(paramRequestPart));
-		assertTrue("MultipartFile parameter not supported", resolver.supportsParameter(paramMultipartFileNotAnnot));
-		assertTrue("Part parameter not supported", resolver.supportsParameter(paramPart));
-		assertTrue("List<Part> parameter not supported", resolver.supportsParameter(paramPartList));
-		assertTrue("Part[] parameter not supported", resolver.supportsParameter(paramPartArray));
-		assertTrue("MultipartFile parameter not supported", resolver.supportsParameter(paramMultipartFile));
-		assertTrue("List<MultipartFile> parameter not supported", resolver.supportsParameter(paramMultipartFileList));
-		assertTrue("MultipartFile[] parameter not supported", resolver.supportsParameter(paramMultipartFileArray));
-		assertFalse("non-RequestPart parameter should not be supported", resolver.supportsParameter(paramInt));
-		assertFalse("@RequestParam args should not be supported", resolver.supportsParameter(paramRequestParamAnnot));
+		assertTrue(resolver.supportsParameter(paramRequestPart));
+		assertTrue(resolver.supportsParameter(paramNamedRequestPart));
+		assertTrue(resolver.supportsParameter(paramValidRequestPart));
+		assertTrue(resolver.supportsParameter(paramMultipartFile));
+		assertTrue(resolver.supportsParameter(paramMultipartFileList));
+		assertTrue(resolver.supportsParameter(paramMultipartFileArray));
+		assertFalse(resolver.supportsParameter(paramInt));
+		assertTrue(resolver.supportsParameter(paramMultipartFileNotAnnot));
+		assertTrue(resolver.supportsParameter(paramPart));
+		assertTrue(resolver.supportsParameter(paramPartList));
+		assertTrue(resolver.supportsParameter(paramPartArray));
+		assertFalse(resolver.supportsParameter(paramRequestParamAnnot));
+		assertTrue(resolver.supportsParameter(optionalMultipartFile));
+		assertTrue(resolver.supportsParameter(optionalMultipartFileList));
+		assertTrue(resolver.supportsParameter(optionalPart));
+		assertTrue(resolver.supportsParameter(optionalPartList));
+		assertTrue(resolver.supportsParameter(optionalRequestPart));
 	}
 
 	@Test
 	public void resolveMultipartFile() throws Exception {
 		Object actual = resolver.resolveArgument(paramMultipartFile, null, webRequest, null);
-		assertNotNull(actual);
 		assertSame(multipartFile1, actual);
 	}
 
 	@Test
 	public void resolveMultipartFileList() throws Exception {
 		Object actual = resolver.resolveArgument(paramMultipartFileList, null, webRequest, null);
-		assertNotNull(actual);
 		assertTrue(actual instanceof List);
 		assertEquals(Arrays.asList(multipartFile1, multipartFile2), actual);
 	}
@@ -175,6 +184,7 @@ public class RequestPartMethodArgumentResolverTests {
 		assertNotNull(actual);
 		assertTrue(actual instanceof MultipartFile[]);
 		MultipartFile[] parts = (MultipartFile[]) actual;
+		assertEquals(2, parts.length);
 		assertEquals(parts[0], multipartFile1);
 		assertEquals(parts[1], multipartFile2);
 	}
@@ -184,6 +194,7 @@ public class RequestPartMethodArgumentResolverTests {
 		MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
 		MultipartFile expected = new MockMultipartFile("multipartFileNotAnnot", "Hello World".getBytes());
 		request.addFile(expected);
+		request.addFile(new MockMultipartFile("otherPart", "", "text/plain", "Hello World".getBytes()));
 		webRequest = new ServletWebRequest(request);
 
 		Object result = resolver.resolveArgument(paramMultipartFileNotAnnot, null, webRequest, null);
@@ -194,52 +205,52 @@ public class RequestPartMethodArgumentResolverTests {
 
 	@Test
 	public void resolvePartArgument() throws Exception {
-		MockPart expected = new MockPart("part", "Hello World".getBytes());
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		request.setMethod("POST");
 		request.setContentType("multipart/form-data");
+		MockPart expected = new MockPart("part", "Hello World".getBytes());
 		request.addPart(expected);
+		request.addPart(new MockPart("otherPart", "Hello World".getBytes()));
 		webRequest = new ServletWebRequest(request);
 
 		Object result = resolver.resolveArgument(paramPart, null, webRequest, null);
-
 		assertTrue(result instanceof Part);
 		assertEquals("Invalid result", expected, result);
 	}
 
 	@Test
 	public void resolvePartListArgument() throws Exception {
-		MockPart part1 = new MockPart("requestPart1", "Hello World 1".getBytes());
-		MockPart part2 = new MockPart("requestPart2", "Hello World 2".getBytes());
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		request.setMethod("POST");
 		request.setContentType("multipart/form-data");
+		MockPart part1 = new MockPart("requestPart", "Hello World 1".getBytes());
+		MockPart part2 = new MockPart("requestPart", "Hello World 2".getBytes());
 		request.addPart(part1);
 		request.addPart(part2);
+		request.addPart(new MockPart("otherPart", "Hello World".getBytes()));
 		webRequest = new ServletWebRequest(request);
 
 		Object result = resolver.resolveArgument(paramPartList, null, webRequest, null);
-
 		assertTrue(result instanceof List);
 		assertEquals(Arrays.asList(part1, part2), result);
 	}
 
 	@Test
 	public void resolvePartArrayArgument() throws Exception {
-		MockPart part1 = new MockPart("requestPart1", "Hello World 1".getBytes());
-		MockPart part2 = new MockPart("requestPart2", "Hello World 2".getBytes());
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		request.setMethod("POST");
 		request.setContentType("multipart/form-data");
+		MockPart part1 = new MockPart("requestPart", "Hello World 1".getBytes());
+		MockPart part2 = new MockPart("requestPart", "Hello World 2".getBytes());
 		request.addPart(part1);
 		request.addPart(part2);
+		request.addPart(new MockPart("otherPart", "Hello World".getBytes()));
 		webRequest = new ServletWebRequest(request);
 
 		Object result = resolver.resolveArgument(paramPartArray, null, webRequest, null);
-
 		assertTrue(result instanceof Part[]);
 		Part[] parts = (Part[]) result;
-		assertThat(parts, Matchers.arrayWithSize(2));
+		assertEquals(2, parts.length);
 		assertEquals(parts[0], part1);
 		assertEquals(parts[1], part2);
 	}
@@ -302,8 +313,8 @@ public class RequestPartMethodArgumentResolverTests {
 	@Test  // SPR-9079
 	public void isMultipartRequestPut() throws Exception {
 		this.multipartRequest.setMethod("PUT");
-		Object actual = resolver.resolveArgument(paramMultipartFile, null, webRequest, null);
-		assertSame(multipartFile1, actual);
+		Object actualValue = resolver.resolveArgument(paramMultipartFile, null, webRequest, null);
+		assertSame(multipartFile1, actualValue);
 	}
 
 	@Test
@@ -311,12 +322,16 @@ public class RequestPartMethodArgumentResolverTests {
 		MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
 		MultipartFile expected = new MockMultipartFile("optionalMultipartFile", "Hello World".getBytes());
 		request.addFile(expected);
+		request.addFile(new MockMultipartFile("otherPart", "", "text/plain", "Hello World".getBytes()));
 		webRequest = new ServletWebRequest(request);
 
-		Object result = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		Object actualValue = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", expected, ((Optional) actualValue).get());
 
-		assertTrue(result instanceof Optional);
-		assertEquals("Invalid result", expected, ((Optional) result).get());
+		actualValue = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", expected, ((Optional) actualValue).get());
 	}
 
 	@Test
@@ -324,10 +339,62 @@ public class RequestPartMethodArgumentResolverTests {
 		MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
 		webRequest = new ServletWebRequest(request);
 
-		Object result = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		Object actualValue = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
 
-		assertTrue(result instanceof Optional);
-		assertFalse("Invalid result", ((Optional) result).isPresent());
+		actualValue = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+	}
+
+	@Test
+	public void resolveOptionalMultipartFileArgumentWithoutMultipartRequest() throws Exception {
+		webRequest = new ServletWebRequest(new MockHttpServletRequest());
+
+		Object actualValue = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalMultipartFile, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+	}
+
+	@Test
+	public void resolveOptionalMultipartFileList() throws Exception {
+		MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
+		MultipartFile expected = new MockMultipartFile("requestPart", "Hello World".getBytes());
+		request.addFile(expected);
+		request.addFile(new MockMultipartFile("otherPart", "", "text/plain", "Hello World".getBytes()));
+		webRequest = new ServletWebRequest(request);
+
+		Object actualValue = resolver.resolveArgument(optionalMultipartFileList, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", Collections.singletonList(expected), ((Optional) actualValue).get());
+
+		actualValue = resolver.resolveArgument(optionalMultipartFileList, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", Collections.singletonList(expected), ((Optional) actualValue).get());
+	}
+
+	@Test
+	public void resolveOptionalMultipartFileListNotPresent() throws Exception {
+		MockMultipartHttpServletRequest request = new MockMultipartHttpServletRequest();
+		webRequest = new ServletWebRequest(request);
+
+		Object actualValue = resolver.resolveArgument(optionalMultipartFileList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalMultipartFileList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+	}
+
+	@Test
+	public void resolveOptionalMultipartFileListWithoutMultipartRequest() throws Exception {
+		webRequest = new ServletWebRequest(new MockHttpServletRequest());
+
+		Object actualValue = resolver.resolveArgument(optionalMultipartFileList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalMultipartFileList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
 	}
 
 	@Test
@@ -337,12 +404,16 @@ public class RequestPartMethodArgumentResolverTests {
 		request.setMethod("POST");
 		request.setContentType("multipart/form-data");
 		request.addPart(expected);
+		request.addPart(new MockPart("otherPart", "Hello World".getBytes()));
 		webRequest = new ServletWebRequest(request);
 
-		Object result = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		Object actualValue = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", expected, ((Optional) actualValue).get());
 
-		assertTrue(result instanceof Optional);
-		assertEquals("Invalid result", expected, ((Optional) result).get());
+		actualValue = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", expected, ((Optional) actualValue).get());
 	}
 
 	@Test
@@ -352,36 +423,108 @@ public class RequestPartMethodArgumentResolverTests {
 		request.setContentType("multipart/form-data");
 		webRequest = new ServletWebRequest(request);
 
-		Object result = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		Object actualValue = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
 
-		assertTrue(result instanceof Optional);
-		assertFalse("Invalid result", ((Optional) result).isPresent());
+		actualValue = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+	}
+
+	@Test
+	public void resolveOptionalPartArgumentWithoutMultipartRequest() throws Exception {
+		webRequest = new ServletWebRequest(new MockHttpServletRequest());
+
+		Object actualValue = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalPart, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+	}
+
+	@Test
+	public void resolveOptionalPartList() throws Exception {
+		MockPart expected = new MockPart("requestPart", "Hello World".getBytes());
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("POST");
+		request.setContentType("multipart/form-data");
+		request.addPart(expected);
+		request.addPart(new MockPart("otherPart", "Hello World".getBytes()));
+		webRequest = new ServletWebRequest(request);
+
+		Object actualValue = resolver.resolveArgument(optionalPartList, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", Collections.singletonList(expected), ((Optional) actualValue).get());
+
+		actualValue = resolver.resolveArgument(optionalPartList, null, webRequest, null);
+		assertTrue(actualValue instanceof Optional);
+		assertEquals("Invalid result", Collections.singletonList(expected), ((Optional) actualValue).get());
+	}
+
+	@Test
+	public void resolveOptionalPartListNotPresent() throws Exception {
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("POST");
+		request.setContentType("multipart/form-data");
+		webRequest = new ServletWebRequest(request);
+
+		Object actualValue = resolver.resolveArgument(optionalPartList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalPartList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+	}
+
+	@Test
+	public void resolveOptionalPartListWithoutMultipartRequest() throws Exception {
+		webRequest = new ServletWebRequest(new MockHttpServletRequest());
+
+		Object actualValue = resolver.resolveArgument(optionalPartList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalPartList, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
 	}
 
 	@Test
 	public void resolveOptionalRequestPart() throws Exception {
 		SimpleBean simpleBean = new SimpleBean("foo");
-
 		given(messageConverter.canRead(SimpleBean.class, MediaType.TEXT_PLAIN)).willReturn(true);
 		given(messageConverter.read(eq(SimpleBean.class), isA(HttpInputMessage.class))).willReturn(simpleBean);
 
 		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
-		Object actualValue = resolver.resolveArgument(optionalRequestPart, mavContainer, webRequest, new ValidatingBinderFactory());
 
+		Object actualValue = resolver.resolveArgument(optionalRequestPart, mavContainer, webRequest, new ValidatingBinderFactory());
+		assertEquals("Invalid argument value", Optional.of(simpleBean), actualValue);
+		assertFalse("The requestHandled flag shouldn't change", mavContainer.isRequestHandled());
+
+		actualValue = resolver.resolveArgument(optionalRequestPart, mavContainer, webRequest, new ValidatingBinderFactory());
 		assertEquals("Invalid argument value", Optional.of(simpleBean), actualValue);
 		assertFalse("The requestHandled flag shouldn't change", mavContainer.isRequestHandled());
 	}
 
 	@Test
 	public void resolveOptionalRequestPartNotPresent() throws Exception {
-		given(messageConverter.canRead(SimpleBean.class, MediaType.TEXT_PLAIN)).willReturn(true);
-		given(messageConverter.read(eq(SimpleBean.class), isA(RequestPartServletServerHttpRequest.class))).willReturn(null);
-
-		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
-		Object actualValue = resolver.resolveArgument(optionalRequestPart, mavContainer, webRequest, new ValidatingBinderFactory());
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setMethod("POST");
+		request.setContentType("multipart/form-data");
+		webRequest = new ServletWebRequest(request);
 
+		Object actualValue = resolver.resolveArgument(optionalRequestPart, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalRequestPart, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+	}
+
+	@Test
+	public void resolveOptionalRequestPartWithoutMultipartRequest() throws Exception {
+		webRequest = new ServletWebRequest(new MockHttpServletRequest());
+
+		Object actualValue = resolver.resolveArgument(optionalRequestPart, null, webRequest, null);
+		assertEquals("Invalid argument value", Optional.empty(), actualValue);
+
+		actualValue = resolver.resolveArgument(optionalRequestPart, null, webRequest, null);
 		assertEquals("Invalid argument value", Optional.empty(), actualValue);
-		assertFalse("The requestHandled flag shouldn't change", mavContainer.isRequestHandled());
 	}
 
 
@@ -390,8 +533,8 @@ public class RequestPartMethodArgumentResolverTests {
 		given(messageConverter.read(eq(SimpleBean.class), isA(HttpInputMessage.class))).willReturn(argValue);
 
 		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
-		Object actualValue = resolver.resolveArgument(parameter, mavContainer, webRequest, new ValidatingBinderFactory());
 
+		Object actualValue = resolver.resolveArgument(parameter, mavContainer, webRequest, new ValidatingBinderFactory());
 		assertEquals("Invalid argument value", argValue, actualValue);
 		assertFalse("The requestHandled flag shouldn't change", mavContainer.isRequestHandled());
 	}
@@ -425,22 +568,26 @@ public class RequestPartMethodArgumentResolverTests {
 		}
 	}
 
+
 	@SuppressWarnings("unused")
-	public void handle(@RequestPart SimpleBean requestPart,
-					   @RequestPart(value="requestPart", required=false) SimpleBean namedRequestPart,
-					   @Valid @RequestPart("requestPart") SimpleBean validRequestPart,
-					   @RequestPart("requestPart") MultipartFile multipartFile,
-					   @RequestPart("requestPart") List<MultipartFile> multipartFileList,
-					   @RequestPart("requestPart") MultipartFile[] multipartFileArray,
-					   int i,
-					   MultipartFile multipartFileNotAnnot,
-					   Part part,
-					   @RequestPart("part") List<Part> partList,
-					   @RequestPart("part") Part[] partArray,
-					   @RequestParam MultipartFile requestParamAnnot,
-					   Optional<MultipartFile> optionalMultipartFile,
-					   Optional<Part> optionalPart,
-					   @RequestPart("requestPart") Optional<SimpleBean> optionalRequestPart) {
+	public void handle(
+			@RequestPart SimpleBean requestPart,
+			@RequestPart(value="requestPart", required=false) SimpleBean namedRequestPart,
+			@Valid @RequestPart("requestPart") SimpleBean validRequestPart,
+			@RequestPart("requestPart") MultipartFile multipartFile,
+			@RequestPart("requestPart") List<MultipartFile> multipartFileList,
+			@RequestPart("requestPart") MultipartFile[] multipartFileArray,
+			int i,
+			MultipartFile multipartFileNotAnnot,
+			Part part,
+			@RequestPart("requestPart") List<Part> partList,
+			@RequestPart("requestPart") Part[] partArray,
+			@RequestParam MultipartFile requestParamAnnot,
+			Optional<MultipartFile> optionalMultipartFile,
+			@RequestPart("requestPart") Optional<List<MultipartFile>> optionalMultipartFileList,
+			Optional<Part> optionalPart,
+			@RequestPart("requestPart") Optional<List<Part>> optionalPartList,
+			@RequestPart("requestPart") Optional<SimpleBean> optionalRequestPart) {
 	}
 
 }

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/support/DefaultHandlerExceptionResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -47,7 +47,9 @@ import org.springframework.web.servlet.mvc.multiaction.NoSuchRequestHandlingMeth
 
 import static org.junit.Assert.*;
 
-/** @author Arjen Poutsma */
+/**
+ * @author Arjen Poutsma
+ */
 public class DefaultHandlerExceptionResolverTests {
 
 	private DefaultHandlerExceptionResolver exceptionResolver;
@@ -174,7 +176,9 @@ public class DefaultHandlerExceptionResolverTests {
 		assertNotNull("No ModelAndView returned", mav);
 		assertTrue("No Empty ModelAndView returned", mav.isEmpty());
 		assertEquals("Invalid status code", 400, response.getStatus());
-		assertEquals("Required request part 'name' is not present.", response.getErrorMessage());
+		assertTrue(response.getErrorMessage().contains("request part"));
+		assertTrue(response.getErrorMessage().contains("name"));
+		assertTrue(response.getErrorMessage().contains("not present"));
 	}
 
 	@Test
@@ -211,6 +215,7 @@ public class DefaultHandlerExceptionResolverTests {
 		assertSame(ex, request.getAttribute("javax.servlet.error.exception"));
 	}
 
+
 	@SuppressWarnings("unused")
 	public void handle(String arg) {
 	}