GWT上传

客户端:

class FileUploadForm extends FormPanel{

   private FileUpload fileUpload;

   public FileUploadForm(){
       setEncoding(FormPanel.ENCODING_MULTIPART);
       setMethod(FormPanel.METHOD_POST);
       VerticalPanel holder = new VerticalPanel();
       fileUpload = new FileUpload();
       fileUpload.setName("file");
       fileUpload.setWidth(300);
       holder.add(fileUpload);
 }

  public String getFileName(){
      return fileUpload.getFilename();
  }
}

  上面的代码是构造一个简单的文件上传的Panel。

 

  使用FileUploadForm：

  (1):设置Action:fileUploadForm.setAction(String url);//

  (2):上传前的事件:fileUploadForm.addSubmitHandler(SubmitHandler handler);//

  (3):上传完成事件:fileUploadForm.addSubmitCompleteHandler(SubmitCompleteHandler handler);//

   如果服务器端用诸如out.print写入数据返回到客户端，在SubmitCompleteHandler里可以用如下方式获得。

//获取输出流里的数据
String result = event.getResults();
HTML html = new HTML(result);
result = html.getText();

  (4):执行上传操作:fileUploadForm.submit();

 

  服务端:

ServletFileUpload upload = new ServletFileUpload();
FileItemIterator iter= upload.getItemIterator(req);
while(iter.hasNext()){
 FileItemStream item = iter.next();
 InputStream in = item.openStream();//打开上传的文件流
}