ExtForm提交Servlet

Ext.getCmp('<%=TabID%>_form').getForm().submit({

                         url: 'UploadServlet',     //后台处理页面（可以是php，asp，aspx，jsp等等）

                         waitMsg: '正在上传...',

                      failure:function(form1,action){           
                      Ext.MessageBox.hide();   
                      Ext.MessageBox.alert('Error',action.result.msg);                   success: function(form1,action){     
                      Ext.MessageBox.hide();     
                      Ext.MessageBox.alert('Success',action.result.msg);     
                  }     

                     });

Servlet

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {    response.setContentType("text/html; charset=utf-8");  
       // arg1.setContentType("text/html; charset=ISO-8859-4");            ModelAndView aaa=null;  
        String data="{success:flase,msg:'上传失败'}";  

  
     try{            DiskFileItemFactory factory=new DiskFileItemFactory();            factory.setSizeThreshold(1024*1024*20);            factory.setRepository(new File(request.getRealPath("/")+""));
           System.out.println(factory.getRepository());
                 //根据上传工厂获取servletfileupload对象
           ServletFileUpload upload=new ServletFileUpload(factory);            //设置上传文件的大小
                 upload.setSizeMax(1024*1024*20);
                 List items=null;
              try {
       items=upload.parseRequest(request);
       System.out.println(items.size());
      } catch (FileUploadException e) {
       // TODO Auto-generated catch block
       e.printStackTrace();               for(Iterator it=items.iterator();it.hasNext();){
              FileItem item=(FileItem)it.next();
              if(item.isFormField()){
                 String name=item.getFieldName();
                 System.out.println(name);
                 String value=item.getString("gbk");               }else{                  String fieldName=item.getFieldName();                  String fileName=item.getName();                    System.out.println(fileName);                  String contentType=item.getContentType();
                 System.out.println(contentType);                  FileOutputStream fos=new FileOutputStream(request.getRealPath("/")+"()));                  if(item.isInMemory()){
                  fos.write(item.get());
                 }else{                   InputStream is=item.getInputStream();
                  byte[] buffer=new byte[1024];
                  int len;
                  while((len=is.read(buffer))>0){
                   fos.write(buffer, 0, len);                   is.close();
                  fos.close();                  }                             data="{success:true,msg:'上传成功'}";  
          } catch (Exception e) {  
              data="{success:flase,msg:'上传失败'}";                // aaa=new ModelAndView(this.getFormView());  
          } finally{  
          response.getWriter().write(data);  
          response.getWriter().flush();                  //return aaa;       

}