Support List<Part> method arguments

Issue: SPR-10591

spring-web/src/main/java/org/springframework/web/method/annotation/RequestParamMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -17,6 +17,7 @@
 package org.springframework.web.method.annotation;
 
 import java.beans.PropertyEditor;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
@@ -161,6 +162,10 @@ public class RequestParamMethodArgumentResolver extends AbstractNamedValueMethod
 			assertIsMultipartRequest(servletRequest);
 			arg = servletRequest.getPart(name);
 		}
+		else if (isPartCollection(parameter)) {
+			assertIsMultipartRequest(servletRequest);
+			arg = new ArrayList(servletRequest.getParts());
+		}
 		else {
 			arg = null;
 			if (multipartRequest != null) {
@@ -188,14 +193,24 @@ public class RequestParamMethodArgumentResolver extends AbstractNamedValueMethod
 	}
 
 	private boolean isMultipartFileCollection(MethodParameter parameter) {
+		Class<?> collectionType = getCollectionParameterType(parameter);
+		return ((collectionType != null) && collectionType.equals(MultipartFile.class));
+	}
+
+	private boolean isPartCollection(MethodParameter parameter) {
+		Class<?> collectionType = getCollectionParameterType(parameter);
+		return ((collectionType != null) && "javax.servlet.http.Part".equals(collectionType.getName()));
+	}
+
+	private Class<?> getCollectionParameterType(MethodParameter parameter) {
 		Class<?> paramType = parameter.getParameterType();
 		if (Collection.class.equals(paramType) || List.class.isAssignableFrom(paramType)){
 			Class<?> valueType = GenericCollectionTypeResolver.getCollectionParameterType(parameter);
-			if (valueType != null && valueType.equals(MultipartFile.class)) {
-				return true;
+			if (valueType != null) {
+				return valueType;
 			}
 		}
-		return false;
+		return null;
 	}
 
 	@Override

spring-web/src/test/java/org/springframework/web/method/annotation/RequestParamMethodArgumentResolverTests.java

@@ -68,7 +68,7 @@ public class RequestParamMethodArgumentResolverTests {
 	private MethodParameter paramStringNotAnnot;
 	private MethodParameter paramMultipartFileNotAnnot;
 	private MethodParameter paramMultipartFileList;
-	private MethodParameter paramServlet30Part;
+	private MethodParameter paramPart;
 	private MethodParameter paramRequestPartAnnot;
 	private MethodParameter paramRequired;
 	private MethodParameter paramNotRequired;
@@ -99,8 +99,8 @@ public class RequestParamMethodArgumentResolverTests {
 		paramMultipartFileNotAnnot.initParameterNameDiscovery(paramNameDiscoverer);
 		paramMultipartFileList = new MethodParameter(method, 7);
 		paramMultipartFileList.initParameterNameDiscovery(paramNameDiscoverer);
-		paramServlet30Part = new MethodParameter(method, 8);
-		paramServlet30Part.initParameterNameDiscovery(paramNameDiscoverer);
+		paramPart = new MethodParameter(method, 8);
+		paramPart.initParameterNameDiscovery(paramNameDiscoverer);
 		paramRequestPartAnnot = new MethodParameter(method, 9);
 		paramRequired = new MethodParameter(method, 10);
 		paramNotRequired = new MethodParameter(method, 11);
@@ -119,7 +119,7 @@ public class RequestParamMethodArgumentResolverTests {
 		assertFalse("non-@RequestParam parameter supported", resolver.supportsParameter(paramMap));
 		assertTrue("Simple type params supported w/o annotations", resolver.supportsParameter(paramStringNotAnnot));
 		assertTrue("MultipartFile parameter not supported", resolver.supportsParameter(paramMultipartFileNotAnnot));
-		assertTrue("Part parameter not supported", resolver.supportsParameter(paramServlet30Part));
+		assertTrue("Part parameter not supported", resolver.supportsParameter(paramPart));
 
 		resolver = new RequestParamMethodArgumentResolver(null, false);
 		assertFalse(resolver.supportsParameter(paramStringNotAnnot));
@@ -220,15 +220,15 @@ public class RequestParamMethodArgumentResolverTests {
 	}
 
 	@Test
-	public void resolveServlet30Part() throws Exception {
-		MockPart expected = new MockPart("servlet30Part", "Hello World".getBytes());
+	public void resolvePart() throws Exception {
+		MockPart expected = new MockPart("part", "Hello World".getBytes());
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		request.setMethod("POST");
 		request.setContentType("multipart/form-data");
 		request.addPart(expected);
 		webRequest = new ServletWebRequest(request);
 
-		Object result = resolver.resolveArgument(paramServlet30Part, null, webRequest, null);
+		Object result = resolver.resolveArgument(paramPart, null, webRequest, null);
 
 		assertTrue(result instanceof Part);
 		assertEquals("Invalid result", expected, result);
@@ -331,7 +331,7 @@ public class RequestParamMethodArgumentResolverTests {
 			String stringNotAnnot,
 			MultipartFile multipartFileNotAnnot,
 			List<MultipartFile> multipartFileList,
-			Part servlet30Part,
+			Part part,
 			@RequestPart MultipartFile requestPartAnnot,
 			@RequestParam(value = "name") String paramRequired,
 			@RequestParam(value = "name", required=false) String paramNotRequired) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -17,8 +17,10 @@
 package org.springframework.web.servlet.mvc.method.annotation;
 
 import java.lang.annotation.Annotation;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+
 import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.core.GenericCollectionTypeResolver;
@@ -130,8 +132,13 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 			arg = multipartRequest.getFiles(partName);
 		}
 		else if ("javax.servlet.http.Part".equals(parameter.getParameterType().getName())) {
+			assertIsMultipartRequest(servletRequest);
 			arg = servletRequest.getPart(partName);
 		}
+		else if (isPartCollection(parameter)) {
+			assertIsMultipartRequest(servletRequest);
+			arg = new ArrayList(servletRequest.getParts());
+		}
 		else {
 			try {
 				HttpInputMessage inputMessage = new RequestPartServletServerHttpRequest(servletRequest, partName);
@@ -177,14 +184,24 @@ public class RequestPartMethodArgumentResolver extends AbstractMessageConverterM
 	}
 
 	private boolean isMultipartFileCollection(MethodParameter parameter) {
+		Class<?> collectionType = getCollectionParameterType(parameter);
+		return ((collectionType != null) && collectionType.equals(MultipartFile.class));
+	}
+
+	private boolean isPartCollection(MethodParameter parameter) {
+		Class<?> collectionType = getCollectionParameterType(parameter);
+		return ((collectionType != null) && "javax.servlet.http.Part".equals(collectionType.getName()));
+	}
+
+	private Class<?> getCollectionParameterType(MethodParameter parameter) {
 		Class<?> paramType = parameter.getParameterType();
 		if (Collection.class.equals(paramType) || List.class.isAssignableFrom(paramType)){
 			Class<?> valueType = GenericCollectionTypeResolver.getCollectionParameterType(parameter);
-			if (valueType != null && valueType.equals(MultipartFile.class)) {
-				return true;
+			if (valueType != null) {
+				return valueType;
 			}
 		}
-		return false;
+		return null;
 	}
 
 	private void validate(WebDataBinder binder, MethodParameter parameter) throws MethodArgumentNotValidException {

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

@@ -53,6 +53,8 @@ import org.springframework.web.multipart.support.RequestPartServletServerHttpReq
 
 import static org.junit.Assert.*;
 import static org.mockito.BDDMockito.*;
+import static org.mockito.Matchers.*;
+import static org.mockito.Mockito.*;
 
 /**
  * Test fixture with {@link RequestPartMethodArgumentResolver} and mock {@link HttpMessageConverter}.
@@ -75,7 +77,8 @@ public class RequestPartMethodArgumentResolverTests {
 	private MethodParameter paramMultipartFileList;
 	private MethodParameter paramInt;
 	private MethodParameter paramMultipartFileNotAnnot;
-	private MethodParameter paramServlet30Part;
+	private MethodParameter paramPart;
+	private MethodParameter paramPartList;
 	private MethodParameter paramRequestParamAnnot;
 
 	private NativeWebRequest webRequest;
@@ -88,8 +91,9 @@ public class RequestPartMethodArgumentResolverTests {
 	@Before
 	public void setUp() throws Exception {
 
-		Method method = getClass().getMethod("handle", SimpleBean.class, SimpleBean.class, SimpleBean.class,
-				MultipartFile.class, List.class, Integer.TYPE, MultipartFile.class, Part.class, MultipartFile.class);
+		Method method = getClass().getMethod("handle", SimpleBean.class, SimpleBean.class,
+				SimpleBean.class, MultipartFile.class, List.class, Integer.TYPE,
+				MultipartFile.class, Part.class, List.class, MultipartFile.class);
 
 		paramRequestPart = new MethodParameter(method, 0);
 		paramRequestPart.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
@@ -100,9 +104,10 @@ public class RequestPartMethodArgumentResolverTests {
 		paramInt = new MethodParameter(method, 5);
 		paramMultipartFileNotAnnot = new MethodParameter(method, 6);
 		paramMultipartFileNotAnnot.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
-		paramServlet30Part = new MethodParameter(method, 7);
-		paramServlet30Part.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
-		paramRequestParamAnnot = new MethodParameter(method, 8);
+		paramPart = new MethodParameter(method, 7);
+		paramPart.initParameterNameDiscovery(new LocalVariableTableParameterNameDiscoverer());
+		paramPartList = new MethodParameter(method, 8);
+		paramRequestParamAnnot = new MethodParameter(method, 9);
 
 		messageConverter = mock(HttpMessageConverter.class);
 		given(messageConverter.getSupportedMediaTypes()).willReturn(Collections.singletonList(MediaType.TEXT_PLAIN));
@@ -123,7 +128,7 @@ public class RequestPartMethodArgumentResolverTests {
 	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(paramServlet30Part));
+		assertTrue("Part parameter not supported", resolver.supportsParameter(paramPart));
 		assertFalse("non-RequestPart parameter supported", resolver.supportsParameter(paramInt));
 		assertFalse("@RequestParam args not supported", resolver.supportsParameter(paramRequestParamAnnot));
 	}
@@ -157,20 +162,37 @@ public class RequestPartMethodArgumentResolverTests {
 	}
 
 	@Test
-	public void resolveServlet30PartArgument() throws Exception {
-		MockPart expected = new MockPart("servlet30Part", "Hello World".getBytes());
+	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");
 		request.addPart(expected);
 		webRequest = new ServletWebRequest(request);
 
-		Object result = resolver.resolveArgument(paramServlet30Part, null, webRequest, null);
+		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");
+		request.addPart(part1);
+		request.addPart(part2);
+		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 resolveRequestPart() throws Exception {
 		testResolveArgument(new SimpleBean("foo"), paramRequestPart);
@@ -276,7 +298,8 @@ public class RequestPartMethodArgumentResolverTests {
 					   @RequestPart("requestPart") List<MultipartFile> multipartFileList,
 					   int i,
 					   MultipartFile multipartFileNotAnnot,
-					   Part servlet30Part,
+					   Part part,
+					   @RequestPart("requestPart") List<Part> partList,
 					   @RequestParam MultipartFile requestParamAnnot) {
 	}