GWT 批量上传

<context-param>
    <!-- max size of the upload request -->
    <param-name>maxSize</param-name>
    <param-value>3145728</param-value>
  </context-param>
  <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  -->
    <param-name>slowUploads</param-name>
    <param-value>200</param-value>
  </context-param>

  <servlet>
    <servlet-name>uploadServlet</servlet-name>
    <!-- This is the default servlet, it puts files in session -->
    <servlet-class>gwtupload.server.UploadServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>uploadServlet</servlet-name>
    <url-pattern>*.gupld</url-pattern>
  </servlet-mapping>

/**
 * An example of a MultiUploader panel using a very simple upload progress widget
 * The example also uses PreloadedImage to display uploaded images.
 * 
 * @author Manolo Carrasco Moñino
 */
public class MultipleUploadSample implements EntryPoint {

  // A panel where the thumbnails of uploaded images will be shown
  private FlowPanel panelImages = new FlowPanel();

  public void onModuleLoad() {
    // Attach the image viewer to the document
    RootPanel.get("thumbnails").add(panelImages);
    
    // Create a new uploader panel and attach it to the document
    MultiUploader defaultUploader = new MultiUploader();
    RootPanel.get("default").add(defaultUploader);

    // Add a finish handler which will load the image once the upload finishes
    defaultUploader.addOnFinishUploadHandler(onFinishUploaderHandler);
  }

  // Load the image in the document and in the case of success attach it to the viewer
  private IUploader.OnFinishUploaderHandler onFinishUploaderHandler = new IUploader.OnFinishUploaderHandler() {
    public void onFinish(IUploader uploader) {
      if (uploader.getStatus() == Status.SUCCESS) {

        new PreloadedImage(uploader.fileUrl(), showImage);
        
        // The server sends useful information to the client by default
        UploadedInfo info = uploader.getServerInfo();
        System.out.println("File name " + info.name);
        System.out.println("File content-type " + info.ctype);
        System.out.println("File size " + info.size);

        // You can send any customized message and parse it 
        System.out.println("Server message " + info.message);
      }
    }
  };

  // Attach an image to the pictures viewer
  private OnLoadPreloadedImageHandler showImage = new OnLoadPreloadedImageHandler() {
    public void onLoad(PreloadedImage image) {
      image.setWidth("75px");
      panelImages.add(image);
    }
  };
}

final MultiUploader upload = new MultiUploader();
        
         upload.setServletPath(GWT.getModuleBaseURL()
                               + "uploadServlet");
     
         Label b = new Label();
         b.setWidth("116px");
         b.setStyleName("uploadFormButton");
         upload.addButton(b);


         add(upload,
             624,
             0);