javaWeb实现文件下载
2018-07-20 本文已影响0人
相信灬你一直在
今天学习了JavaWeb实现文件下载，为了以后方便查找并让需要的人学习，今儿把代码献上！！！！
大笑
大笑
首先写一个jsp页面
字体加粗的为主要内容：
download.jsp：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>文件下载</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<a href="/download/DownloadServlet?filename=1.jpg">文件下载</a>
</body>
</html>
然后在定义一个Servlet，如下：
DownloadServlet：
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
//设置ContentType字段值
response.setContentType("text/html;charset=utf-8");
//获取所要下载的文件名称
String filename = request.getParameter("filename");
//下载文件所在目录
String folder = "/filename/";
//通知浏览器以下载的方式打开
response.addHeader("Content-type", "appllication/octet-stream");
response.addHeader("Content-Disposition", "attachment;filename="+filename);
//通知文件流读取文件
InputStream in = getServletContext().getResourceAsStream(folder+filename);
//获取response对象的输出流
OutputStream out = response.getOutputStream();
byte[] buffer = new byte[1024];
int len;
//循环取出流中的数据
while((len = in.read(buffer)) != -1){
out.write(buffer,0,len);
}
}
用到的架包：commons-fileupload-1.3.1.jar、commons-io-2.4.jar
本例子中用到的架包下载地址：http://commons.apache.org/
