Add javax.servlet.http.Part support for data binding

Prior to this commit, Multipart databinding would only support
MultiPartFile databinding using commons-multipart.

Now the WebRequestDataBinder supports Part and List<Part>
databinding for Servlet 3.0 compliant containers.

Issue: SPR-10591

spring-web/src/main/java/org/springframework/web/bind/support/WebRequestDataBinder.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.
@@ -16,11 +16,20 @@
 
 package org.springframework.web.bind.support;
 
+import java.io.IOException;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.Part;
+
 import org.springframework.beans.MutablePropertyValues;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.StringUtils;
 import org.springframework.validation.BindException;
 import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.multipart.MultipartException;
 import org.springframework.web.multipart.MultipartRequest;
 
 /**
@@ -50,6 +59,7 @@ import org.springframework.web.multipart.MultipartRequest;
  * ...</pre>
  *
  * @author Juergen Hoeller
+ * @author Brian Clozel
  * @since 2.5.2
  * @see #bind(org.springframework.web.context.request.WebRequest)
  * @see #registerCustomEditor
@@ -59,6 +69,7 @@ import org.springframework.web.multipart.MultipartRequest;
  */
 public class WebRequestDataBinder extends WebDataBinder {
 
+
 	/**
 	 * Create a new WebRequestDataBinder instance, with default object name.
 	 * @param target the target object to bind onto (or {@code null}
@@ -89,22 +100,27 @@ public class WebRequestDataBinder extends WebDataBinder {
 	 * <p>Multipart files are bound via their parameter name, just like normal
 	 * HTTP parameters: i.e. "uploadedFile" to an "uploadedFile" bean property,
 	 * invoking a "setUploadedFile" setter method.
-	 * <p>The type of the target property for a multipart file can be MultipartFile,
+	 * <p>The type of the target property for a multipart file can be Part, MultipartFile,
 	 * byte[], or String. The latter two receive the contents of the uploaded file;
 	 * all metadata like original file name, content type, etc are lost in those cases.
 	 * @param request request with parameters to bind (can be multipart)
 	 * @see org.springframework.web.multipart.MultipartRequest
 	 * @see org.springframework.web.multipart.MultipartFile
-	 * @see #bindMultipartFiles
+	 * @see javax.servlet.http.Part
 	 * @see #bind(org.springframework.beans.PropertyValues)
 	 */
 	public void bind(WebRequest request) {
 		MutablePropertyValues mpvs = new MutablePropertyValues(request.getParameterMap());
-		if (request instanceof NativeWebRequest) {
+
+		if(isMultipartRequest(request) && (request instanceof NativeWebRequest)) {
 			MultipartRequest multipartRequest = ((NativeWebRequest) request).getNativeRequest(MultipartRequest.class);
 			if (multipartRequest != null) {
 				bindMultipart(multipartRequest.getMultiFileMap(), mpvs);
 			}
+			else if (ClassUtils.hasMethod(HttpServletRequest.class, "getParts")) {
+				HttpServletRequest serlvetRequest = ((NativeWebRequest) request).getNativeRequest(HttpServletRequest.class);
+				new Servlet3MultipartHelper().bindParts(serlvetRequest, mpvs);
+			}
 		}
 		doBind(mpvs);
 	}
@@ -121,4 +137,37 @@ public class WebRequestDataBinder extends WebDataBinder {
 		}
 	}
 
+	/**
+	 * Check if the request is a multipart request (by checking its Content-Type header).
+	 *
+	 * @param request request with parameters to bind
+	 */
+	private boolean isMultipartRequest(WebRequest request) {
+		String contentType = request.getHeader("Content-Type");
+		return ((contentType != null) && StringUtils.startsWithIgnoreCase(contentType, "multipart"));
+	}
+
+
+	/**
+	 * Encapsulate Part binding code for Servlet 3.0+ only containers.
+	 * @see javax.servlet.http.Part
+	 */
+	private static class Servlet3MultipartHelper {
+
+		public void bindParts(HttpServletRequest request, MutablePropertyValues mpvs) {
+			try {
+				for(Part part : request.getParts()) {
+					mpvs.add(part.getName(), part);
+				}
+			}
+			catch (IOException ex) {
+				throw new MultipartException("Failed to get request parts", ex);
+			}
+			catch(ServletException ex) {
+				throw new MultipartException("Failed to get request parts", ex);
+			}
+		}
+
+	}
+
 }

spring-web/src/test/java/org/springframework/web/bind/support/WebRequestDataBinderIntegrationTests.java

@@ -0,0 +1,203 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.bind.support;
+
+import java.io.IOException;
+import java.util.List;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.Part;
+
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.Resource;
+import org.springframework.http.MediaType;
+import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
+import org.springframework.mock.web.test.MockMultipartFile;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.SocketUtils;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.context.request.ServletWebRequest;
+
+import static org.junit.Assert.*;
+
+
+/**
+ * @author Brian Clozel
+ */
+public class WebRequestDataBinderIntegrationTests {
+
+	protected static String baseUrl;
+
+	protected static MediaType contentType;
+
+	private static Server jettyServer;
+
+	private RestTemplate template;
+
+	private static PartsServlet partsServlet;
+
+	private static PartListServlet partListServlet;
+
+
+	@Before
+	public void createTemplate() {
+		template = new RestTemplate(new HttpComponentsClientHttpRequestFactory());
+	}
+
+	@BeforeClass
+	public static void startJettyServer() throws Exception {
+		int port = SocketUtils.findAvailableTcpPort();
+		jettyServer = new Server(port);
+		baseUrl = "http://localhost:" + port;
+		ServletContextHandler handler = new ServletContextHandler();
+
+		partsServlet = new PartsServlet();
+		partListServlet = new PartListServlet();
+
+		handler.addServlet(new ServletHolder(partsServlet), "/parts");
+		handler.addServlet(new ServletHolder(partListServlet), "/partlist");
+		jettyServer.setHandler(handler);
+		jettyServer.start();
+	}
+
+	@AfterClass
+	public static void stopJettyServer() throws Exception {
+		if (jettyServer != null) {
+			jettyServer.stop();
+		}
+	}
+
+
+	@Test
+	public void testPartsBinding() {
+
+		PartsBean bean = new PartsBean();
+		partsServlet.setBean(bean);
+
+		MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
+		MockMultipartFile firstPart = new MockMultipartFile("fileName", "aValue".getBytes());
+		parts.add("firstPart", firstPart);
+		parts.add("secondPart", "secondValue");
+
+		template.postForLocation(baseUrl + "/parts", parts);
+
+		assertNotNull(bean.getFirstPart());
+		assertNotNull(bean.getSecondPart());
+	}
+
+	@Test
+	public void testPartListBinding() {
+
+		PartListBean bean = new PartListBean();
+		partListServlet.setBean(bean);
+
+		MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
+		parts.add("partList", "first value");
+		parts.add("partList", "second value");
+		Resource logo = new ClassPathResource("/org/springframework/http/converter/logo.jpg");
+		parts.add("partList", logo);
+
+		template.postForLocation(baseUrl + "/partlist", parts);
+
+		assertNotNull(bean.getPartList());
+		assertEquals(parts.size(), bean.getPartList().size());
+	}
+
+
+	@SuppressWarnings("serial")
+	private abstract static class AbstractStandardMultipartServlet<T> extends HttpServlet {
+
+		private T bean;
+
+		@Override
+		public void service(HttpServletRequest request, HttpServletResponse response) throws
+				ServletException, IOException {
+
+			WebRequestDataBinder binder = new WebRequestDataBinder(bean);
+			ServletWebRequest webRequest = new ServletWebRequest(request, response);
+
+			binder.bind(webRequest);
+
+			response.setStatus(HttpServletResponse.SC_OK);
+		}
+
+		public void setBean(T bean) {
+			this.bean = bean;
+		}
+	}
+
+	private static class PartsBean {
+
+		public Part firstPart;
+
+		public Part secondPart;
+
+		public Part getFirstPart() {
+			return firstPart;
+		}
+
+		@SuppressWarnings("unused")
+		public void setFirstPart(Part firstPart) {
+			this.firstPart = firstPart;
+		}
+
+		public Part getSecondPart() {
+			return secondPart;
+		}
+
+		@SuppressWarnings("unused")
+		public void setSecondPart(Part secondPart) {
+			this.secondPart = secondPart;
+		}
+	}
+
+	@SuppressWarnings("serial")
+	private static class PartsServlet extends AbstractStandardMultipartServlet<PartsBean> {
+
+	}
+
+	private static class PartListBean {
+
+		public List<Part> partList;
+
+		public List<Part> getPartList() {
+			return partList;
+		}
+
+		@SuppressWarnings("unused")
+		public void setPartList(List<Part> partList) {
+			this.partList = partList;
+		}
+	}
+
+	@SuppressWarnings("serial")
+	private static class PartListServlet extends AbstractStandardMultipartServlet<PartListBean> {
+
+	}
+
+}