WebDataBinder and @MVC request param binding detect and introspect MultipartFile arrays as well (SPR-2784)

org.springframework.web/src/main/java/org/springframework/web/bind/ServletRequestDataBinder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -105,7 +105,7 @@ public class ServletRequestDataBinder extends WebDataBinder {
 		MutablePropertyValues mpvs = new ServletRequestParameterPropertyValues(request);
 		if (request instanceof MultipartRequest) {
 			MultipartRequest multipartRequest = (MultipartRequest) request;
-			bindMultipartFiles(multipartRequest.getFileMap(), mpvs);
+			bindMultipart(multipartRequest.getMultiFileMap(), mpvs);
 		}
 		doBind(mpvs);
 	}

org.springframework.web/src/main/java/org/springframework/web/bind/WebDataBinder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2010 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.bind;
 
 import java.lang.reflect.Array;
+import java.util.List;
 import java.util.Map;
 
 import org.springframework.beans.MutablePropertyValues;
@@ -276,7 +277,10 @@ public class WebDataBinder extends DataBinder {
 	 * @param mpvs the property values to be bound (can be modified)
 	 * @see org.springframework.web.multipart.MultipartFile
 	 * @see #setBindEmptyMultipartFiles
+	 * @deprecated as of Spring 3.0, in favor of {@link #bindMultipart} which binds
+	 * all multipart files, even if more than one sent for the same name
 	 */
+	@Deprecated
 	protected void bindMultipartFiles(Map<String, MultipartFile> multipartFiles, MutablePropertyValues mpvs) {
 		for (Map.Entry<String, MultipartFile> entry : multipartFiles.entrySet()) {
 			String key = entry.getKey();
@@ -287,4 +291,30 @@ public class WebDataBinder extends DataBinder {
 		}
 	}
 
+	/**
+	 * Bind all multipart files contained in the given request, if any
+	 * (in case of a multipart request).
+	 * <p>Multipart files will only be added to the property values if they
+	 * are not empty or if we're configured to bind empty multipart files too.
+	 * @param multipartFiles Map of field name String to MultipartFile object
+	 * @param mpvs the property values to be bound (can be modified)
+	 * @see org.springframework.web.multipart.MultipartFile
+	 * @see #setBindEmptyMultipartFiles
+	 */
+	protected void bindMultipart(Map<String, List<MultipartFile>> multipartFiles, MutablePropertyValues mpvs) {
+		for (Map.Entry<String, List<MultipartFile>> entry : multipartFiles.entrySet()) {
+			String key = entry.getKey();
+			List<MultipartFile> values = entry.getValue();
+			if (values.size() == 1) {
+				MultipartFile value = values.get(0);
+				if (isBindEmptyMultipartFiles() || !value.isEmpty()) {
+					mpvs.add(key, value);
+				}
+			}
+			else {
+				mpvs.add(key, values);
+			}
+		}
+	}
+
 }

org.springframework.web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodInvoker.java

@@ -78,6 +78,7 @@ import org.springframework.web.bind.support.WebBindingInitializer;
 import org.springframework.web.bind.support.WebRequestDataBinder;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.multipart.MultipartRequest;
 
 /**
@@ -153,7 +154,7 @@ public class HandlerMethodInvoker {
 				if (debug) {
 					logger.debug("Invoking model attribute method: " + attributeMethodToInvoke);
 				}
-				String attrName = AnnotationUtils.findAnnotation(attributeMethodToInvoke, ModelAttribute.class).value();
+				String attrName = AnnotationUtils.findAnnotation(attributeMethod, ModelAttribute.class).value();
 				if (!"".equals(attrName) && implicitModel.containsAttribute(attrName)) {
 					continue;
 				}
@@ -381,7 +382,7 @@ public class HandlerMethodInvoker {
 				boolean debug = logger.isDebugEnabled();
 				for (Method initBinderMethod : initBinderMethods) {
 					Method methodToInvoke = BridgeMethodResolver.findBridgedMethod(initBinderMethod);
-					String[] targetNames = AnnotationUtils.findAnnotation(methodToInvoke, InitBinder.class).value();
+					String[] targetNames = AnnotationUtils.findAnnotation(initBinderMethod, InitBinder.class).value();
 					if (targetNames.length == 0 || Arrays.asList(targetNames).contains(attrName)) {
 						Object[] initBinderArgs =
 								resolveInitBinderArguments(handler, methodToInvoke, binder, webRequest);
@@ -481,15 +482,25 @@ public class HandlerMethodInvoker {
 		Object paramValue = null;
 		MultipartRequest multipartRequest = webRequest.getNativeRequest(MultipartRequest.class);
 		if (multipartRequest != null) {
-			paramValue = multipartRequest.getFile(paramName);
+			List<MultipartFile> files = multipartRequest.getFiles(paramName);
+			if (!files.isEmpty()) {
+				if (files.size() == 1 && !paramType.isArray() && !Collection.class.isAssignableFrom(paramType)) {
+					paramValue = files.get(0);
+				}
+				else {
+					paramValue = files;
+				}
+			}
 		}
 		if (paramValue == null) {
 			String[] paramValues = webRequest.getParameterValues(paramName);
-			if (paramValues != null && !paramType.isArray()) {
-				paramValue = (paramValues.length == 1 ? paramValues[0] : paramValues);
-			}
-			else {
-				paramValue = paramValues;
+			if (paramValues != null) {
+				if (paramValues.length == 1 && !paramType.isArray() && !Collection.class.isAssignableFrom(paramType)) {
+					paramValue = paramValues[0];
+				}
+				else {
+					paramValue = paramValues;
+				}
 			}
 		}
 		if (paramValue == null) {

org.springframework.web/src/main/java/org/springframework/web/bind/support/WebRequestDataBinder.java

@@ -103,7 +103,7 @@ public class WebRequestDataBinder extends WebDataBinder {
 		if (request instanceof NativeWebRequest) {
 			MultipartRequest multipartRequest = ((NativeWebRequest) request).getNativeRequest(MultipartRequest.class);
 			if (multipartRequest != null) {
-				bindMultipartFiles(multipartRequest.getFileMap(), mpvs);
+				bindMultipart(multipartRequest.getMultiFileMap(), mpvs);
 			}
 		}
 		doBind(mpvs);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -64,7 +64,6 @@ public interface MultipartRequest {
 	 * 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 MultipartFile} objects as values
-	 * @see MultipartFile
 	 */
 	Map<String, MultipartFile> getFileMap();
 
@@ -72,7 +71,6 @@ public interface MultipartRequest {
 	 * 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
 	 * @since 3.0
 	 */
 	MultiValueMap<String, MultipartFile> getMultiFileMap();