記錄3種jsp下載文件的方法

[java]
<% 
  response.setContentType("application/x-download");//設置為下載application/x-download 
  String filedownload = "/要下載的文件名";//即將下載的文件的相對路徑 
  String filedisplay = "最終要顯示給用戶的保存文件名";//下載文件時顯示的文件保存名稱 
  String filenamedisplay = URLEncoder.encode(filedisplay,"UTF-8"); 
  response.addHeader("Content-Disposition","attachment;filename=" + filedisplay); 
    
  try 
  { 
  RequestDispatcher dis = application.getRequestDispatcher(filedownload); 
  if(dis!= null) 
  { 
  dis.forward(request,response); 
  } 
  response.flushBuffer(); 
  } 
  catch(Exception e) 
  { 
  e.printStackTrace(); 
  } 
  finally 
  { 
    
  } 
%> 

 
[javascript]
<%@page language="java" contentType="application/x-msdownload" pageEncoding="gb2312"%> 
<% 
  //關於文件下載時采用文件流輸出的方式處理： 
  //加上response.reset()，並且所有的％>後面不要換行，包括最後一個； 
 
  response.reset();//可以加也可以不加 
  response.setContentType("application/x-download"); 
 
//application.getRealPath("/main/mvplayer/CapSetup.msi");獲取的物理路徑 
 
String filedownload = "想辦法找到要提供下載的文件的物理路徑＋文件名"; 
 String filedisplay = "給用戶提供的下載文件名"; 
  String filedisplay = URLEncoder.encode(filedisplay,"UTF-8"); 
  response.addHeader("Content-Disposition","attachment;filename=" + filedisplay); 
 
  java.io.OutputStream outp = null; 
  java.io.FileInputStream in = null; 
  try 
  { 
  outp = response.getOutputStream(); 
  in = new FileInputStream(filenamedownload); 
 
  byte[] b = new byte[1024]; 
  int i = 0; 
 
  while((i = in.read(b)) > 0) 
  { 
  outp.write(b, 0, i); 
  } 
//   
outp.flush(); 
//要加以下兩句話，否則會報錯 
//java.lang.IllegalStateException: getOutputStream() has already been called for //this response   
out.clear(); 
out = pageContext.pushBody(); 
} 
  catch(Exception e) 
  { 
  System.out.println("Error!"); 
  e.printStackTrace(); 
  } 
  finally 
  { 
  if(in != null) 
  { 
  in.close(); 
  in = null; 
  } 
//這裡不能關閉   
//if(outp != null) 
  //{ 
  //outp.close(); 
  //outp = null; 
  //} 
  } 
%> 
 
 
[java]
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%> 
<a href="do_download.jsp?url=xxxxxx">點擊下載 千千動聽</a> 
 
 
 
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%> 
<%@page import="com.jspsmart.upload.SmartUpload"%> 
 
 
<% 
     
    SmartUpload su=new SmartUpload(); 
    su.initialize(pageContext); 
    su.setContentDisposition(null);//禁止浏覽器打開文件 只能下載 
    su.downloadFile("upload/1.txt"); 
    //out.clear(); 
    //out=pageContext.pushBody(); 
 %> 

作者 cn_bboy