SPR-2784: Support MultipartFile-array property

org.springframework.core/src/main/java/org/springframework/util/LinkedMultiValueMap.java

@@ -64,7 +64,6 @@ public class LinkedMultiValueMap<K, V> implements MultiValueMap<K, V> {
 		this.targetMap = new LinkedHashMap<K, List<V>>(otherMap);
 	}
 
-
 	// MultiValueMap implementation
 
 	public void add(K key, V value) {
@@ -87,6 +86,19 @@ public class LinkedMultiValueMap<K, V> implements MultiValueMap<K, V> {
 		this.targetMap.put(key, values);
 	}
 
+	public void setAll(Map<K, V> values) {
+		for (Entry<K, V> entry : values.entrySet()) {
+			set(entry.getKey(), entry.getValue());
+		}
+	}
+
+	public Map<K, V> toSingleValueMap() {
+		LinkedHashMap<K, V> singleValueMap = new LinkedHashMap<K,V>(this.targetMap.size());
+		for (Entry<K, List<V>> entry : targetMap.entrySet()) {
+			singleValueMap.put(entry.getKey(), entry.getValue().get(0));
+		}
+		return singleValueMap;
+	}
 
 	// Map implementation
 

org.springframework.core/src/main/java/org/springframework/util/MultiValueMap.java

@@ -48,4 +48,16 @@ public interface MultiValueMap<K, V> extends Map<K, List<V>> {
 	 */
 	void set(K key, V value);
 
+	/**
+	 * Set the given values under.
+	 * @param values the values.
+	 */
+	void setAll(Map<K, V> values);
+
+	/**
+	 * Returns the first values contained in this {@code MultiValueMap}.
+	 * @return a single value representation of this map
+	 */
+	Map<K, V> toSingleValueMap();
+
 }

org.springframework.test/src/main/java/org/springframework/mock/web/MockMultipartHttpServletRequest.java

@@ -20,8 +20,11 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.List;
 
 import org.springframework.util.Assert;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.multipart.MultipartHttpServletRequest;
 
@@ -35,12 +38,13 @@ import org.springframework.web.multipart.MultipartHttpServletRequest;
  *
  * @author Juergen Hoeller
  * @author Eric Crampton
+ * @author Arjen Poutsma
  * @since 2.0
  * @see MockMultipartFile
  */
 public class MockMultipartHttpServletRequest extends MockHttpServletRequest implements MultipartHttpServletRequest {
 
-	private final Map<String, MultipartFile> multipartFiles = new LinkedHashMap<String, MultipartFile>();
+	private final MultiValueMap<String, MultipartFile> multipartFiles = new LinkedMultiValueMap<String, MultipartFile>();
 
 
 	/**
@@ -50,7 +54,7 @@ public class MockMultipartHttpServletRequest extends MockHttpServletRequest impl
 	 */
 	public void addFile(MultipartFile file) {
 		Assert.notNull(file, "MultipartFile must not be null");
-		this.multipartFiles.put(file.getName(), file);
+		this.multipartFiles.add(file.getName(), file);
 	}
 
 	public Iterator<String> getFileNames() {
@@ -58,11 +62,25 @@ public class MockMultipartHttpServletRequest extends MockHttpServletRequest impl
 	}
 
 	public MultipartFile getFile(String name) {
-		return this.multipartFiles.get(name);
+		return this.multipartFiles.getFirst(name);
 	}
 
+	public List<MultipartFile> getFiles(String name) {
+		List<MultipartFile> multipartFiles = this.multipartFiles.get(name);
+		if (multipartFiles != null) {
+			return multipartFiles;
+		}
+		else {
+			return Collections.emptyList();
+		}
+	}
+	
 	public Map<String, MultipartFile> getFileMap() {
-		return Collections.unmodifiableMap(this.multipartFiles);
+		return Collections.unmodifiableMap(this.multipartFiles.toSingleValueMap());
+	}
+
+	public MultiValueMap<String, MultipartFile> getMultiFileMap() {
+		return new LinkedMultiValueMap<String, MultipartFile>(Collections.unmodifiableMap(this.multipartFiles));
 	}
 
 }

org.springframework.test/src/main/java/org/springframework/mock/web/portlet/MockMultipartActionRequest.java

@@ -20,8 +20,11 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.List;
 
 import org.springframework.util.Assert;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.portlet.multipart.MultipartActionRequest;
 
@@ -34,12 +37,13 @@ import org.springframework.web.portlet.multipart.MultipartActionRequest;
  * populate these mock requests with files.
  *
  * @author Juergen Hoeller
+ * @author Arjen Poutsma
  * @since 2.0
  * @see org.springframework.mock.web.MockMultipartFile
  */
 public class MockMultipartActionRequest extends MockActionRequest implements MultipartActionRequest {
 
-	private final Map<String, MultipartFile> multipartFiles = new LinkedHashMap<String, MultipartFile>();
+	private final MultiValueMap<String, MultipartFile> multipartFiles = new LinkedMultiValueMap<String, MultipartFile>();
 
 
 	/**
@@ -49,7 +53,7 @@ public class MockMultipartActionRequest extends MockActionRequest implements Mul
 	 */
 	public void addFile(MultipartFile file) {
 		Assert.notNull(file, "MultipartFile must not be null");
-		this.multipartFiles.put(file.getName(), file);
+		this.multipartFiles.add(file.getName(), file);
 	}
 
 	public Iterator<String> getFileNames() {
@@ -57,11 +61,25 @@ public class MockMultipartActionRequest extends MockActionRequest implements Mul
 	}
 
 	public MultipartFile getFile(String name) {
-		return this.multipartFiles.get(name);
+		return this.multipartFiles.getFirst(name);
 	}
 
+	public List<MultipartFile> getFiles(String name) {
+		List<MultipartFile> multipartFiles = this.multipartFiles.get(name);
+		if (multipartFiles != null) {
+			return multipartFiles;
+		}
+		else {
+			return Collections.emptyList();
+		}
+	}	
+
 	public Map<String, MultipartFile> getFileMap() {
-		return Collections.unmodifiableMap(this.multipartFiles);
+		return Collections.unmodifiableMap(this.multipartFiles.toSingleValueMap());
+	}
+
+	public MultiValueMap<String, MultipartFile> getMultiFileMap() {
+		return new LinkedMultiValueMap<String, MultipartFile>(Collections.unmodifiableMap(this.multipartFiles));
 	}
 
 }

org.springframework.web.portlet/src/main/java/org/springframework/web/portlet/multipart/DefaultMultipartActionRequest.java

@@ -23,22 +23,26 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
+import java.util.List;
 import javax.portlet.ActionRequest;
 import javax.portlet.filter.ActionRequestWrapper;
 
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 
 /**
  * Default implementation of the {@link MultipartActionRequest} interface.
  * Provides management of pre-generated parameter values.
  *
  * @author Juergen Hoeller
+ * @author Arjen Poutsma
  * @since 2.0
  * @see PortletMultipartResolver
  */
 public class DefaultMultipartActionRequest extends ActionRequestWrapper implements MultipartActionRequest {
 
-	private Map<String, MultipartFile> multipartFiles;
+	private MultiValueMap<String, MultipartFile> multipartFiles;
 
 	private Map<String, String[]> multipartParameters;
 
@@ -51,7 +55,7 @@ public class DefaultMultipartActionRequest extends ActionRequestWrapper implemen
 	 * with Strings as keys and String arrays as values
 	 */
 	public DefaultMultipartActionRequest(
-			ActionRequest request, Map<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) {
+			ActionRequest request, MultiValueMap<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) {
 
 		super(request);
 		setMultipartFiles(mpFiles);
@@ -72,13 +76,27 @@ public class DefaultMultipartActionRequest extends ActionRequestWrapper implemen
 	}
 
 	public MultipartFile getFile(String name) {
-		return getMultipartFiles().get(name);
+		return getMultipartFiles().getFirst(name);
 	}
 
+	public List<MultipartFile> getFiles(String name) {
+		List<MultipartFile> multipartFiles = getMultipartFiles().get(name);
+		if (multipartFiles != null) {
+			return multipartFiles;
+		}
+		else {
+			return Collections.emptyList();
+		}
+	}
+	
+
 	public Map<String, MultipartFile> getFileMap() {
-		return getMultipartFiles();
+		return getMultipartFiles().toSingleValueMap();
 	}
 
+	public MultiValueMap<String, MultipartFile> getMultiFileMap() {
+		return getMultipartFiles();
+	}
 
 	@Override
 	public Enumeration<String> getParameterNames() {
@@ -120,11 +138,12 @@ public class DefaultMultipartActionRequest extends ActionRequestWrapper implemen
 
 
 	/**
-	 * Set a Map with parameter names as keys and MultipartFile objects as values.
+	 * Set a Map with parameter names as keys and list of MultipartFile objects as values.
 	 * To be invoked by subclasses on initialization.
 	 */
-	protected final void setMultipartFiles(Map<String, MultipartFile> multipartFiles) {
-		this.multipartFiles = Collections.unmodifiableMap(multipartFiles);
+	protected final void setMultipartFiles(MultiValueMap<String, MultipartFile> multipartFiles) {
+		this.multipartFiles =
+				new LinkedMultiValueMap<String, MultipartFile>(Collections.unmodifiableMap(multipartFiles));
 	}
 
 	/**
@@ -132,7 +151,7 @@ public class DefaultMultipartActionRequest extends ActionRequestWrapper implemen
 	 * lazily initializing it if necessary.
 	 * @see #initializeMultipart()
 	 */
-	protected Map<String, MultipartFile> getMultipartFiles() {
+	protected MultiValueMap<String, MultipartFile> getMultipartFiles() {
 		if (this.multipartFiles == null) {
 			initializeMultipart();
 		}

org.springframework.web.portlet/src/test/java/org/springframework/mock/web/portlet/MockMultipartActionRequest.java

@@ -20,8 +20,11 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.List;
 
 import org.springframework.util.Assert;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.portlet.multipart.MultipartActionRequest;
 
@@ -34,12 +37,13 @@ import org.springframework.web.portlet.multipart.MultipartActionRequest;
  * populate these mock requests with files.
  *
  * @author Juergen Hoeller
+ * @author Arjen Poutsma
  * @since 2.0
  * @see org.springframework.mock.web.MockMultipartFile
  */
 public class MockMultipartActionRequest extends MockActionRequest implements MultipartActionRequest {
 
-	private final Map<String, MultipartFile> multipartFiles = new LinkedHashMap<String, MultipartFile>();
+	private final MultiValueMap<String, MultipartFile> multipartFiles = new LinkedMultiValueMap<String, MultipartFile>();
 
 
 	/**
@@ -49,7 +53,7 @@ public class MockMultipartActionRequest extends MockActionRequest implements Mul
 	 */
 	public void addFile(MultipartFile file) {
 		Assert.notNull(file, "MultipartFile must not be null");
-		this.multipartFiles.put(file.getName(), file);
+		this.multipartFiles.add(file.getName(), file);
 	}
 
 	public Iterator<String> getFileNames() {
@@ -57,11 +61,24 @@ public class MockMultipartActionRequest extends MockActionRequest implements Mul
 	}
 
 	public MultipartFile getFile(String name) {
-		return this.multipartFiles.get(name);
+		return this.multipartFiles.getFirst(name);
+	}
+
+	public List<MultipartFile> getFiles(String name) {
+		List<MultipartFile> multipartFiles = this.multipartFiles.get(name);
+		if (multipartFiles != null) {
+			return multipartFiles;
+		}
+		else {
+			return Collections.emptyList();
+		}
 	}
 
 	public Map<String, MultipartFile> getFileMap() {
-		return Collections.unmodifiableMap(this.multipartFiles);
+		return Collections.unmodifiableMap(this.multipartFiles.toSingleValueMap());
 	}
 
+	public MultiValueMap<String, MultipartFile> getMultiFileMap() {
+		return new LinkedMultiValueMap<String, MultipartFile>(Collections.unmodifiableMap(this.multipartFiles));		 
+	}
 }

org.springframework.web.portlet/src/test/java/org/springframework/web/portlet/ComplexPortletApplicationContext.java

@@ -67,10 +67,13 @@ import org.springframework.web.portlet.multipart.MultipartActionRequest;
 import org.springframework.web.portlet.multipart.PortletMultipartResolver;
 import org.springframework.web.portlet.mvc.Controller;
 import org.springframework.web.portlet.mvc.SimpleControllerHandlerAdapter;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 
 /**
  * @author Juergen Hoeller
  * @author Mark Fisher
+ * @author Arjen Poutsma
  */
 public class ComplexPortletApplicationContext extends StaticPortletApplicationContext {
 
@@ -472,8 +475,8 @@ public class ComplexPortletApplicationContext extends StaticPortletApplicationCo
 				throw new IllegalStateException("Already resolved");
 			}
 			request.setAttribute("resolved", Boolean.TRUE);
-			Map files = new HashMap();
-			files.put("someFile", "someFile");
+			MultiValueMap files = new LinkedMultiValueMap();
+			files.set("someFile", "someFile");
 			Map params = new HashMap();
 			params.put("someParam", "someParam");
 			return new DefaultMultipartActionRequest(request, files, params);

org.springframework.web.servlet/src/test/java/org/springframework/mock/web/MockMultipartHttpServletRequest.java

@@ -20,8 +20,11 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.List;
 
 import org.springframework.util.Assert;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.multipart.MultipartHttpServletRequest;
 
@@ -35,12 +38,13 @@ import org.springframework.web.multipart.MultipartHttpServletRequest;
  *
  * @author Juergen Hoeller
  * @author Eric Crampton
+ * @author Arjen Poutsma
  * @since 2.0
  * @see MockMultipartFile
  */
 public class MockMultipartHttpServletRequest extends MockHttpServletRequest implements MultipartHttpServletRequest {
 
-	private final Map<String, MultipartFile> multipartFiles = new LinkedHashMap<String, MultipartFile>();
+	private final MultiValueMap<String, MultipartFile> multipartFiles = new LinkedMultiValueMap<String, MultipartFile>();
 
 
 	/**
@@ -50,7 +54,7 @@ public class MockMultipartHttpServletRequest extends MockHttpServletRequest impl
 	 */
 	public void addFile(MultipartFile file) {
 		Assert.notNull(file, "MultipartFile must not be null");
-		this.multipartFiles.put(file.getName(), file);
+		this.multipartFiles.add(file.getName(), file);
 	}
 
 	public Iterator<String> getFileNames() {
@@ -58,11 +62,24 @@ public class MockMultipartHttpServletRequest extends MockHttpServletRequest impl
 	}
 
 	public MultipartFile getFile(String name) {
-		return this.multipartFiles.get(name);
+		return this.multipartFiles.getFirst(name);
 	}
 
+	public List<MultipartFile> getFiles(String name) {
+		List<MultipartFile> multipartFiles = this.multipartFiles.get(name);
+		if (multipartFiles != null) {
+			return multipartFiles;
+		}
+		else {
+			return Collections.emptyList();
+		}
+	}	
+
 	public Map<String, MultipartFile> getFileMap() {
-		return Collections.unmodifiableMap(this.multipartFiles);
+		return Collections.unmodifiableMap(this.multipartFiles.toSingleValueMap());
 	}
 
+	public MultiValueMap<String, MultipartFile> getMultiFileMap() {
+		return new LinkedMultiValueMap<String, MultipartFile>(Collections.unmodifiableMap(this.multipartFiles));
+	}
 }

org.springframework.web/src/main/java/org/springframework/http/HttpHeaders.java

@@ -32,6 +32,7 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.TimeZone;
+import java.util.LinkedHashMap;
 
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedCaseInsensitiveMap;
@@ -494,6 +495,19 @@ public class HttpHeaders implements MultiValueMap<String, String> {
 		headers.put(headerName, headerValues);
 	}
 
+	public void setAll(Map<String, String> values) {
+		for (Entry<String, String> entry : values.entrySet()) {
+			set(entry.getKey(), entry.getValue());
+		}
+	}
+
+	public Map<String, String> toSingleValueMap() {
+		LinkedHashMap<String, String> singleValueMap = new LinkedHashMap<String,String>(this.headers.size());
+		for (Entry<String, List<String>> entry : headers.entrySet()) {
+			singleValueMap.put(entry.getKey(), entry.getValue().get(0));
+		}
+		return singleValueMap;
+	}
 
 	// Map implementation
 

org.springframework.web/src/main/java/org/springframework/web/multipart/MultipartRequest.java

@@ -18,6 +18,9 @@ package org.springframework.web.multipart;
 
 import java.util.Iterator;
 import java.util.Map;
+import java.util.List;
+
+import org.springframework.util.MultiValueMap;
 
 /**
  * This interface defines the multipart request access operations
@@ -26,6 +29,7 @@ import java.util.Map;
  * {@link org.springframework.web.portlet.multipart.MultipartActionRequest}.
  *
  * @author Juergen Hoeller
+ * @author Arjen Poutsma
  * @since 2.5.2
  */
 public interface MultipartRequest {
@@ -43,16 +47,33 @@ public interface MultipartRequest {
 	 * Return the contents plus description of an uploaded file in this request,
 	 * or <code>null</code> if it does not exist.
 	 * @param name a String specifying the parameter name of the multipart file
-	 * @return the uploaded content in the form of a {@link org.springframework.web.multipart.MultipartFile} object
+	 * @return the uploaded content in the form of a {@link MultipartFile} object
 	 */
 	MultipartFile getFile(String name);
 
+	/**
+	 * Return the contents plus description of uploaded files in this request,
+	 * or an empty list if it does not exist.
+	 * @param name a String specifying the parameter name of the multipart file
+	 * @return the uploaded content in the form of a {@link MultipartFile} list
+	 */
+	List<MultipartFile> getFiles(String name);
+
 	/**
 	 * Return a {@link java.util.Map} of the multipart files contained in this request.
 	 * @return a map containing the parameter names as keys, and the
-	 * {@link org.springframework.web.multipart.MultipartFile} objects as values
+	 * {@link MultipartFile} objects as values
 	 * @see MultipartFile
 	 */
 	Map<String, MultipartFile> getFileMap();
 
+	/**
+	 * Return a {@link MultiValueMap} of the multipart files contained in this request.
+	 * @return a map containing the parameter names as keys, and a list of
+	 * {@link MultipartFile} objects as values
+	 * @see MultipartFile
+	 */
+	MultiValueMap<String, MultipartFile> getMultiFileMap();
+
+
 }

org.springframework.web/src/main/java/org/springframework/web/multipart/commons/CommonsFileUploadSupport.java

@@ -31,8 +31,9 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.core.io.Resource;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
-import org.springframework.web.multipart.MultipartException;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.util.WebUtils;
 
@@ -213,7 +214,7 @@ public abstract class CommonsFileUploadSupport {
 	 * @see CommonsMultipartFile#CommonsMultipartFile(org.apache.commons.fileupload.FileItem)
 	 */
 	protected MultipartParsingResult parseFileItems(List<FileItem> fileItems, String encoding) {
-		Map<String, MultipartFile> multipartFiles = new HashMap<String, MultipartFile>();
+		MultiValueMap<String, MultipartFile> multipartFiles = new LinkedMultiValueMap<String, MultipartFile>();
 		Map<String, String[]> multipartParameters = new HashMap<String, String[]>();
 
 		// Extract multipart files and multipart parameters.
@@ -249,10 +250,7 @@ public abstract class CommonsFileUploadSupport {
 			else {
 				// multipart file field
 				CommonsMultipartFile file = new CommonsMultipartFile(fileItem);
-				if (multipartFiles.put(file.getName(), file) != null) {
-					throw new MultipartException("Multiple files for field name [" + file.getName() +
-							"] found - not supported by MultipartResolver");
-				}
+				multipartFiles.add(file.getName(), file);
 				if (logger.isDebugEnabled()) {
 					logger.debug("Found multipart file [" + file.getName() + "] of size " + file.getSize() +
 							" bytes with original filename [" + file.getOriginalFilename() + "], stored " +
@@ -290,7 +288,7 @@ public abstract class CommonsFileUploadSupport {
 	 */
 	protected static class MultipartParsingResult {
 
-		private final Map<String, MultipartFile> multipartFiles;
+		private final MultiValueMap<String, MultipartFile> multipartFiles;
 
 		private final Map<String, String[]> multipartParameters;
 
@@ -299,7 +297,7 @@ public abstract class CommonsFileUploadSupport {
 		 * @param mpFiles Map of field name to MultipartFile instance
 		 * @param mpParams Map of field name to form field String value
 		 */
-		public MultipartParsingResult(Map<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) {
+		public MultipartParsingResult(MultiValueMap<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) {
 			this.multipartFiles = mpFiles;
 			this.multipartParameters = mpParams;
 		}
@@ -307,7 +305,7 @@ public abstract class CommonsFileUploadSupport {
 		/**
 		 * Return the multipart files as Map of field name to MultipartFile instance.
 		 */
-		public Map<String, MultipartFile> getMultipartFiles() {
+		public MultiValueMap<String, MultipartFile> getMultipartFiles() {
 			return this.multipartFiles;
 		}
 

org.springframework.web/src/main/java/org/springframework/web/multipart/support/AbstractMultipartHttpServletRequest.java

@@ -19,24 +19,28 @@ package org.springframework.web.multipart.support;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.Map;
+import java.util.List;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletRequestWrapper;
 
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.multipart.MultipartHttpServletRequest;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.LinkedMultiValueMap;
 
 /**
  * Abstract base implementation of the MultipartHttpServletRequest interface.
  * Provides management of pre-generated MultipartFile instances.
  *
  * @author Juergen Hoeller
+ * @author Arjen Poutsma
  * @since 06.10.2003
  */
 public abstract class AbstractMultipartHttpServletRequest extends HttpServletRequestWrapper
 	implements MultipartHttpServletRequest {
 
-	private Map<String, MultipartFile> multipartFiles;
+	private MultiValueMap<String, MultipartFile> multipartFiles;
 
 
 	/**
@@ -53,20 +57,34 @@ public abstract class AbstractMultipartHttpServletRequest extends HttpServletReq
 	}
 
 	public MultipartFile getFile(String name) {
-		return getMultipartFiles().get(name);
+		return getMultipartFiles().getFirst(name);
+	}
+
+	public List<MultipartFile> getFiles(String name) {
+		List<MultipartFile> multipartFiles = getMultipartFiles().get(name);
+		if (multipartFiles != null) {
+			return multipartFiles;
+		}
+		else {
+			return Collections.emptyList();
+		}
 	}
 
 	public Map<String, MultipartFile> getFileMap() {
+		return getMultipartFiles().toSingleValueMap();
+	}
+
+	public MultiValueMap<String, MultipartFile> getMultiFileMap() {
 		return getMultipartFiles();
 	}
 
-
 	/**
-	 * Set a Map with parameter names as keys and MultipartFile objects as values.
+	 * Set a Map with parameter names as keys and list of MultipartFile objects as values.
 	 * To be invoked by subclasses on initialization.
 	 */
-	protected final void setMultipartFiles(Map<String, MultipartFile> multipartFiles) {
-		this.multipartFiles = Collections.unmodifiableMap(multipartFiles);
+	protected final void setMultipartFiles(MultiValueMap<String, MultipartFile> multipartFiles) {
+		this.multipartFiles =
+				new LinkedMultiValueMap<String, MultipartFile>(Collections.unmodifiableMap(multipartFiles));
 	}
 
 	/**
@@ -74,7 +92,7 @@ public abstract class AbstractMultipartHttpServletRequest extends HttpServletReq
 	 * lazily initializing it if necessary.
 	 * @see #initializeMultipart()
 	 */
-	protected Map<String, MultipartFile> getMultipartFiles() {
+	protected MultiValueMap<String, MultipartFile> getMultipartFiles() {
 		if (this.multipartFiles == null) {
 			initializeMultipart();
 		}

org.springframework.web/src/main/java/org/springframework/web/multipart/support/DefaultMultipartHttpServletRequest.java

@@ -25,6 +25,7 @@ import java.util.Set;
 import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.web.multipart.MultipartFile;
+import org.springframework.util.MultiValueMap;
 
 /**
  * Default implementation of the
@@ -33,6 +34,7 @@ import org.springframework.web.multipart.MultipartFile;
  *
  * @author Trevor D. Cook
  * @author Juergen Hoeller
+ * @author Arjen Poutsma
  * @since 29.09.2003
  * @see org.springframework.web.multipart.MultipartResolver
  */
@@ -49,7 +51,7 @@ public class DefaultMultipartHttpServletRequest extends AbstractMultipartHttpSer
 	 * with Strings as keys and String arrays as values
 	 */
 	public DefaultMultipartHttpServletRequest(
-			HttpServletRequest request, Map<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) {
+			HttpServletRequest request, MultiValueMap<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) {
 
 		super(request);
 		setMultipartFiles(mpFiles);

org.springframework.web/src/test/java/org/springframework/web/multipart/commons/CommonsMultipartResolverTests.java

@@ -30,7 +30,6 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
@@ -38,12 +37,13 @@ import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import junit.framework.TestCase;
-
 import org.apache.commons.fileupload.FileItem;
 import org.apache.commons.fileupload.FileItemFactory;
 import org.apache.commons.fileupload.FileUpload;
 import org.apache.commons.fileupload.servlet.ServletFileUpload;
+import static org.junit.Assert.*;
+import org.junit.Test;
+
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.mock.web.MockFilterConfig;
 import org.springframework.mock.web.MockHttpServletRequest;
@@ -59,18 +59,22 @@ import org.springframework.web.multipart.support.ByteArrayMultipartFileEditor;
 import org.springframework.web.multipart.support.MultipartFilter;
 import org.springframework.web.multipart.support.StringMultipartFileEditor;
 import org.springframework.web.util.WebUtils;
+import org.springframework.util.MultiValueMap;
 
 /**
  * @author Juergen Hoeller
+ * @author Arjen Poutsma
  * @since 08.10.2003
  */
-public class CommonsMultipartResolverTests extends TestCase {
+public class CommonsMultipartResolverTests {
 
-	public void testWithApplicationContext() throws Exception {
+	@Test
+	public void withApplicationContext() throws Exception {
 		doTestWithApplicationContext(false);
 	}
 
-	public void testWithApplicationContextAndLazyResolution() throws Exception {
+	@Test
+	public void withApplicationContextAndLazyResolution() throws Exception {
 		doTestWithApplicationContext(true);
 	}
 
@@ -100,10 +104,18 @@ public class CommonsMultipartResolverTests extends TestCase {
 		assertTrue(resolver.isMultipart(originalRequest));
 		MultipartHttpServletRequest request = resolver.resolveMultipart(originalRequest);
 
-		Set parameterNames = new HashSet();
+		doTestParameters(request);
+
+		doTestFiles(request);
+
+		doTestBinding(resolver, originalRequest, request);
+	}
+
+	private void doTestParameters(MultipartHttpServletRequest request) {
+		Set<String> parameterNames = new HashSet<String>();
 		Enumeration parameterEnum = request.getParameterNames();
 		while (parameterEnum.hasMoreElements()) {
-			parameterNames.add(parameterEnum.nextElement());
+			parameterNames.add((String) parameterEnum.nextElement());
 		}
 		assertEquals(3, parameterNames.size());
 		assertTrue(parameterNames.contains("field3"));
@@ -121,10 +133,10 @@ public class CommonsMultipartResolverTests extends TestCase {
 		assertEquals("value4", request.getParameter("field4"));
 		assertEquals("getValue", request.getParameter("getField"));
 
-		List parameterMapKeys = new ArrayList();
-		List parameterMapValues = new ArrayList();
-		for (Iterator parameterMapIter = request.getParameterMap().keySet().iterator(); parameterMapIter.hasNext();) {
-			String key = (String) parameterMapIter.next();
+		List<String> parameterMapKeys = new ArrayList<String>();
+		List<Object> parameterMapValues = new ArrayList<Object>();
+		for (Object o : request.getParameterMap().keySet()) {
+			String key = (String) o;
 			parameterMapKeys.add(key);
 			parameterMapValues.add(request.getParameterMap().get(key));
 		}
@@ -146,11 +158,13 @@ public class CommonsMultipartResolverTests extends TestCase {
 		parameterValues = Arrays.asList((String[]) parameterMapValues.get(getFieldIndex));
 		assertEquals(1, parameterValues.size());
 		assertTrue(parameterValues.contains("getValue"));
+	}
 
-		Set fileNames = new HashSet();
+	private void doTestFiles(MultipartHttpServletRequest request) throws IOException {
+		Set<String> fileNames = new HashSet<String>();
 		Iterator fileIter = request.getFileNames();
 		while (fileIter.hasNext()) {
-			fileNames.add(fileIter.next());
+			fileNames.add((String) fileIter.next());
 		}
 		assertEquals(3, fileNames.size());
 		assertTrue(fileNames.contains("field1"));
@@ -159,7 +173,8 @@ public class CommonsMultipartResolverTests extends TestCase {
 		CommonsMultipartFile file1 = (CommonsMultipartFile) request.getFile("field1");
 		CommonsMultipartFile file2 = (CommonsMultipartFile) request.getFile("field2");
 		CommonsMultipartFile file2x = (CommonsMultipartFile) request.getFile("field2x");
-		Map fileMap = request.getFileMap();
+
+		Map<String, MultipartFile> fileMap = request.getFileMap();
 		assertEquals(3, fileMap.size());
 		assertTrue(fileMap.containsKey("field1"));
 		assertTrue(fileMap.containsKey("field2"));
@@ -168,6 +183,18 @@ public class CommonsMultipartResolverTests extends TestCase {
 		assertEquals(file2, fileMap.get("field2"));
 		assertEquals(file2x, fileMap.get("field2x"));
 
+		MultiValueMap<String, MultipartFile> multiFileMap = request.getMultiFileMap();
+		assertEquals(3, multiFileMap.size());
+		assertTrue(multiFileMap.containsKey("field1"));
+		assertTrue(multiFileMap.containsKey("field2"));
+		assertTrue(multiFileMap.containsKey("field2x"));
+		List<MultipartFile> field1Files = multiFileMap.get("field1");
+		assertEquals(2, field1Files.size());
+		assertTrue(field1Files.contains(file1));
+		assertEquals(file1, multiFileMap.getFirst("field1"));
+		assertEquals(file2, multiFileMap.getFirst("field2"));
+		assertEquals(file2x, multiFileMap.getFirst("field2x"));
+
 		assertEquals("type1", file1.getContentType());
 		assertEquals("type2", file2.getContentType());
 		assertEquals("type2", file2x.getContentType());
@@ -181,18 +208,24 @@ public class CommonsMultipartResolverTests extends TestCase {
 		assertTrue(file1.getInputStream() instanceof ByteArrayInputStream);
 		assertTrue(file2.getInputStream() instanceof ByteArrayInputStream);
 		File transfer1 = new File("C:/transfer1");
-		File transfer2 = new File("C:/transfer2");
 		file1.transferTo(transfer1);
+		File transfer2 = new File("C:/transfer2");
 		file2.transferTo(transfer2);
 		assertEquals(transfer1, ((MockFileItem) file1.getFileItem()).writtenFile);
 		assertEquals(transfer2, ((MockFileItem) file2.getFileItem()).writtenFile);
 
+	}
+
+	private void doTestBinding(MockCommonsMultipartResolver resolver, MockHttpServletRequest originalRequest,
+			MultipartHttpServletRequest request) throws UnsupportedEncodingException {
 		MultipartTestBean1 mtb1 = new MultipartTestBean1();
 		assertEquals(null, mtb1.getField1());
 		assertEquals(null, mtb1.getField2());
 		ServletRequestDataBinder binder = new ServletRequestDataBinder(mtb1, "mybean");
 		binder.registerCustomEditor(byte[].class, new ByteArrayMultipartFileEditor());
 		binder.bind(request);
+		CommonsMultipartFile file1 = (CommonsMultipartFile) request.getFile("field1");
+		CommonsMultipartFile file2 = (CommonsMultipartFile) request.getFile("field2");
 		assertEquals(file1, mtb1.getField1());
 		assertEquals(new String(file2.getBytes()), new String(mtb1.getField2()));
 
@@ -224,7 +257,8 @@ public class CommonsMultipartResolverTests extends TestCase {
 		assertTrue(mtb2.getField1().length() == 0);
 	}
 
-	public void testWithServletContextAndFilter() throws Exception {
+	@Test
+	public void withServletContextAndFilter() throws Exception {
 		StaticWebApplicationContext wac = new StaticWebApplicationContext();
 		wac.setServletContext(new MockServletContext());
 		wac.registerSingleton("filterMultipartResolver", MockCommonsMultipartResolver.class, new MutablePropertyValues());
@@ -240,7 +274,7 @@ public class CommonsMultipartResolverTests extends TestCase {
 		final MultipartFilter filter = new MultipartFilter();
 		filter.init(filterConfig);
 
-		final List files = new ArrayList();
+		final List<MultipartFile> files = new ArrayList<MultipartFile>();
 		final FilterChain filterChain = new FilterChain() {
 			public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse) {
 				MultipartHttpServletRequest request = (MultipartHttpServletRequest) servletRequest;
@@ -263,7 +297,8 @@ public class CommonsMultipartResolverTests extends TestCase {
 		assertTrue(((MockFileItem) file2.getFileItem()).deleted);
 	}
 
-	public void testWithServletContextAndFilterWithCustomBeanName() throws Exception {
+	@Test
+	public void withServletContextAndFilterWithCustomBeanName() throws Exception {
 		StaticWebApplicationContext wac = new StaticWebApplicationContext();
 		wac.setServletContext(new MockServletContext());
 		wac.refresh();
@@ -276,7 +311,7 @@ public class CommonsMultipartResolverTests extends TestCase {
 		MockFilterConfig filterConfig = new MockFilterConfig(wac.getServletContext(), "filter");
 		filterConfig.addInitParameter("multipartResolverBeanName", "myMultipartResolver");
 
-		final List files = new ArrayList();
+		final List<MultipartFile> files = new ArrayList<MultipartFile>();
 		FilterChain filterChain = new FilterChain() {
 			public void doFilter(ServletRequest originalRequest, ServletResponse response) {
 				if (originalRequest instanceof MultipartHttpServletRequest) {
@@ -288,6 +323,7 @@ public class CommonsMultipartResolverTests extends TestCase {
 
 		MultipartFilter filter = new MultipartFilter() {
 			private boolean invoked = false;
+			@Override
 			protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
 					FilterChain filterChain) throws ServletException, IOException {
 				super.doFilterInternal(request, response, filterChain);
@@ -321,15 +357,19 @@ public class CommonsMultipartResolverTests extends TestCase {
 			this.empty = empty;
 		}
 
+		@Override
 		protected FileUpload newFileUpload(FileItemFactory fileItemFactory) {
 			return new ServletFileUpload() {
+				@Override
 				public List parseRequest(HttpServletRequest request) {
 					if (request instanceof MultipartHttpServletRequest) {
 						throw new IllegalStateException("Already a multipart request");
 					}
-					List fileItems = new ArrayList();
+					List<FileItem> fileItems = new ArrayList<FileItem>();
 					MockFileItem fileItem1 = new MockFileItem(
 					    "field1", "type1", empty ? "" : "field1.txt", empty ? "" : "text1");
+					MockFileItem fileItem1x = new MockFileItem(
+					    "field1", "type1", empty ? "" : "field1.txt", empty ? "" : "text1");
 					MockFileItem fileItem2 = new MockFileItem(
 					    "field2", "type2", empty ? "" : "C:/field2.txt", empty ? "" : "text2");
 					MockFileItem fileItem2x = new MockFileItem(
@@ -338,6 +378,7 @@ public class CommonsMultipartResolverTests extends TestCase {
 					MockFileItem fileItem4 = new MockFileItem("field4", null, null, "value4");
 					MockFileItem fileItem5 = new MockFileItem("field4", null, null, "value5");
 					fileItems.add(fileItem1);
+					fileItems.add(fileItem1x);
 					fileItems.add(fileItem2);
 					fileItems.add(fileItem2x);
 					fileItems.add(fileItem3);