Java动态显示文件上传进度实现代码

/*
* 处理附件上传的通知。

* 各位可以继承这个类，来实现自己的特殊处理。 
* 
* @author 赵学庆 www.java2000.net 
*/ 
 public  class UploadListener ... { 
  // 调试模式将在控制台打印出一些数据 
  private  boolean debug;

  // 总数据字节数 
  private  int total;

  // 当前已经处理的数据字节数 
  private  int totalCurrent =  0 ;

  // 延迟，用来调试用，免得速度太快，根本卡看不到进度 
  private  int delay =  0 ;

   /** */ /** 
  * 处理数据通知的方法。

  * 保存已经处理的数据。并且在一定的比例进行延迟。默认每1%

  * 如果不需用延迟，可以删掉内部的代码，加快速度。 
  * 
  * @param size 增加的字节数 
   */ 
   public  void increaseTotalCurrent( long size) ... { 
   this .totalCurrent += size; 
    try  ... { 
    currentRate = totalCurrent *  100  / total; 
     if (currentRate > lastRate) ... { 
      if (delay >  0 ) ... { 
      Thread.sleep(delay); 
     } 
      if (debug) ... { 
      System.out.println( " rate= "  + totalCurrent +  " / "  + total +  " / "  + (totalCurrent *  100  / total)); 
     } 
     lastRate = currentRate; 
    } 
   }  catch (Exception e) ... { 
    e.printStackTrace(); 
   } 
  } 

   /** */ /** 
  * 读取全部自己数 
  * 
  * @return 
   */ 
   public  int getTotal() ... { 
   return total; 
  } 

   /** */ /** 
  * 读取已经处理的字节数 
  * 
  * @return 
   */ 
   public  int getTotalCurrent() ... { 
   return totalCurrent; 
  } 

  private  long lastRate =  0 ;

  private  long currentRate =  0 ;

   public  int getDelay() ... { 
   return delay; 
  } 

   public  void setDelay( int delay) ... { 
   this .delay = delay; 
  } 

   public  void setTotal( int total) ... { 
   this .total = total; 
  } 

   public  boolean isDebug() ... { 
   return debug; 
  } 

   public  void setDebug( boolean debug) ... { 
   this .debug = debug; 
  } 
}

  Upload upload =  new Upload(request); 
  // 增加了侦听进度的代码 
  UploadListener uploadListener =  new UploadListener(); 
  // 这句话我们后面再讨论，这个可是关键 
  session.setAttribute( " uploadListener " ,uploadListener); 
  uploadListener.setDelay( 0 ); 
  uploadListener.setDebug( true ); 
  upload.setUploadListener(uploadListener); 
  upload.parse(); 
  // 这句话同样重要，我们后面再讨论 
  session.setAttribute( " uploadListener " , null );

< script. type = " text/javascript. " > 
 function checkForm() ... { 
  $( " SHOW_FRAME. " ).src = " link.jsp " ; 
  $( ' SUBMIT ' ).disabled = true ; 
  Ext.MessageBox.show( ... { 
   title: ' Please wait... ' , 
   msg: ' Initializing... ' , 
   width: 240 , 
   progress: true , 
   closable: false 
  } ); 
  $( " MAIN_FORM. " ).submit(); 
  return  false ; 
} 
 function setUploadProcess(total,current) ... { 
  var rate = Number(current) / Number(total); 
  Ext.MessageBox.updateProgress(rate, ' Uploading... ' + current + " / " + total); 
   if (Number(current) >= Number(total)) ... { 
   closeUploadProcess(); 
  } 
} 
 function closeUploadProcess() ... { 
  Ext.MessageBox.hide(); 
} 
</ script. > 
< iframe. name = " ACTION_FRAME. " id = " ACTION_FRAME. " width = " 0 " height = " 0 " ></ iframe. > 
< iframe. name = " SHOW_FRAME. " id = " SHOW_FRAME. " width = " 0 " height = " 0 " ></ iframe. > 
< form. method = " OST " id = " MAIN_FORM. " nsubmit = " return checkForm() " enctype = " multipart/form-data "  
  action = " uploadFileSave.jsp " target = " ACTION_FRAME. " > 
  < input type = " file " size = " 50 " name = " file " >  
  < input type = " submit " ID = " SUBMIT " value = " Upload It " > 
</ form. >

<% @ page language = " java " contentType = " text/html; charset=utf-8 " pageEncoding = " utf-8 " %> 
<% @include file = " ../package.inc.jsp " %> 
<% 
  response.setHeader( " ragma " , " no-cache " ); 
  response.setHeader( " Cache-Control " , " no-cache " ); 
  response.setDateHeader( " Expires " , 0 ); 
  response.setBufferSize( 0 ); 
  UploadListener uploadListener =  null ; 
   while (uploadListener ==  null  || uploadListener.getTotalCurrent() <=  0 ) ... { 
   uploadListener = (UploadListener) session.getAttribute( " uploadListener " ); 
   out.print( " . " ); 
   out.flush(); 
   Thread.sleep( 10 ); 
  } 
  long total = uploadListener.getTotal(); 
  out.println(total); 
  long current; 
  out.flush(); 
   while ( true ) ... { 
   current = uploadListener.getTotalCurrent(); 
    if (current >= total) ... { 
    break ; 
   } 
   out.println( " <script. type='text/javascript'>parent.setUploadProcess(' "  + total +  " ',' "  + current +  " ');</script> " ); 
   out.flush(); 
   Thread.sleep( 10 ); 
  } 
%>< script. type = " text/javascript. " > parent.closeUploadProcess(); </ script. >