GWT/GXT – File Upload

<module>
 <inherits name="com.google.gwt.user.User"/>
 <inherits name="com.google.gwt.user.theme.standard.Standard"/>
 <entry-point class="com.mycompany.project.client.EP"/>
 <inherits name="com.extjs.gxt.ui.GXT"/>
 
 <!-- Include GWTUpload library -->
 <inherits name="gwtupload.GWTUpload"/>
 <!-- Load dinamically predefined styles in the library when the app starts -->
 <stylesheet src="Upload.css"/>
 <inherits name="com.mycompany.project.EP"/>
</module>

package com.mycompany.project.client;
 
import com.extjs.gxt.ui.client.Style.LayoutRegion;
import com.extjs.gxt.ui.client.widget.Viewport;
import com.extjs.gxt.ui.client.widget.layout.BorderLayout;
import com.extjs.gxt.ui.client.widget.layout.BorderLayoutData;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;
 
/**
 * Entry point
 */
public class EP implements EntryPoint {
 
	private static Viewport viewport;
 
	private static MyUploader uploader;
 
	public void onModuleLoad() {
 
		viewport = new Viewport();
 
		viewport.setLayout(new BorderLayout());
 
		showUploader();
 
		RootPanel.get().add(viewport);
	}
 
	public static void showUploader() {
		if (uploader == null) {
			uploader = new MyUploader();
			viewport.add(uploader, new BorderLayoutData(LayoutRegion.NORTH,
					MyUploader.SIZE));
			viewport.layout();
		}
	}
 
	public static void closeUploader() {
		if (uploader != null) {
			viewport.remove(uploader);
			viewport.layout();
			uploader = null;
		}
	}
}

package com.mycompany.project.client;
 
import gwtupload.client.IFileInput.FileInputType;
import gwtupload.client.IUploadStatus.Status;
import gwtupload.client.IUploader;
import gwtupload.client.IUploader.OnFinishUploaderHandler;
import gwtupload.client.IUploader.Utils;
import gwtupload.client.MultiUploader;
 
import com.extjs.gxt.ui.client.Style.HorizontalAlignment;
import com.extjs.gxt.ui.client.Style.Scroll;
import com.extjs.gxt.ui.client.event.ButtonEvent;
import com.extjs.gxt.ui.client.event.SelectionListener;
import com.extjs.gxt.ui.client.widget.LayoutContainer;
import com.extjs.gxt.ui.client.widget.VerticalPanel;
import com.extjs.gxt.ui.client.widget.button.Button;
import com.extjs.gxt.ui.client.widget.layout.FitLayout;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.Window;
import com.google.gwt.xml.client.Document;
import com.google.gwt.xml.client.XMLParser;
 
public class MyUploader extends LayoutContainer {
 
	public static final float SIZE = 130;
 
	@Override
	protected void onRender(Element parent, int index) {
		super.onRender(parent, index);
 
		setLayout(new FitLayout());
 
		final VerticalPanel uploaderPanel = new VerticalPanel();
 
		uploaderPanel.setScrollMode(Scroll.AUTO);
 
		uploaderPanel.setSpacing(10);
 
		uploaderPanel.setHorizontalAlign(HorizontalAlignment.RIGHT);
 
		MultiUploader uploader = new MultiUploader(FileInputType.LABEL);
		// we can change the internationalization by creating custom Constants
		// file
 
		uploader.setAvoidRepeatFiles(false);
 
		uploader.setServletPath("uploader.fileUpload");
		uploader.addOnFinishUploadHandler(new OnFinishUploaderHandler() {
			public void onFinish(IUploader uploader) {
 
				if (uploader.getStatus() == Status.SUCCESS) {
 
					String response = uploader.getServerResponse();
 
					if (response != null) {
						Document doc = XMLParser.parse(response);
						String message = Utils.getXmlNodeValue(doc, "message");
						String finished = Utils
						.getXmlNodeValue(doc, "finished");
 
						Window.alert("Server response: \n" + message + "\n"
								+ "finished: " + finished);
					} else {
						Window.alert("Unaccessible server response");
					}
 
					// uploader.reset();
				} else {
					Window.alert("Uploader Status: \n" + uploader.getStatus());
				}
 
			}
		});
 
		uploaderPanel.add(uploader);
 
		Button closeButton = new Button("Close",
				new SelectionListener<ButtonEvent>() {
 
			public void componentSelected(ButtonEvent ce) {
				EP.closeUploader();
			}
 
		});
 
		uploaderPanel.add(closeButton);
 
		add(uploaderPanel);
	}
 
}

package com.mycompany.project.server;
 
import gwtupload.server.UploadAction;
import gwtupload.server.exceptions.UploadActionException;
 
import java.util.List;
 
import javax.servlet.http.HttpServletRequest;
 
import org.apache.commons.fileupload.FileItem;
 
public class FileUploadServlet extends UploadAction {
 
	private static final long serialVersionUID = 1L;
 
	public String executeAction(HttpServletRequest request,
			List<FileItem> sessionFiles) throws UploadActionException {
		String response = "Received file:";
 
		for (FileItem item : sessionFiles) {
			if (!item.isFormField()) {
				try {
 
					// we can save the received file
					// File file = File.createTempFile("receivedFile", ".tmp",
					// new File("C:\\"));
					// item.write(file);
 
					// response += " " + file.getPath();
 
					response += " " + item.getName() + ", size=  "
					+ item.getSize() + ", ContentType= "
					+ item.getContentType();
 
				} catch (Exception e) {
					throw new UploadActionException(e.getMessage());
				}
			}
		}
 
		try {
			// Remove files from session
			removeSessionFileItems(request);
		} catch (Exception e) {
			throw new UploadActionException(e.getMessage());
		}
 
		// Send information of the received files to the client.
		return response;
	}
 
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app
 PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd">
 
<web-app>
 
 <!-- Default page to serve -->
 <welcome-file-list>
 <welcome-file>EP.html</welcome-file>
 </welcome-file-list>
 
 <!-- customized file upload servlet -->
 <servlet>
 <servlet-name>fileUploadServlet</servlet-name>
 <servlet-class>com.mycompany.project.server.FileUploadServlet</servlet-class>
 </servlet>
 
 <servlet-mapping>
 <servlet-name>fileUploadServlet</servlet-name>
 <url-pattern>*.fileUpload</url-pattern>
 </servlet-mapping>
 
 <!-- max size of the upload request -->
 <context-param>
 <param-name>maxSize</param-name>
 <param-value>262144000</param-value>
 </context-param>
 
 <!-- Useful in development mode to slow down the uploads in fast networks.
 Put the number of milliseconds to sleep in each block received in the server.
 false or 0, means don't use slow uploads  -->
 <context-param>
 <param-name>slowUploads</param-name>
 <param-value>0</param-value>
 </context-param>
 
</web-app>