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. >