文件下载

最新推荐文章于 2025-07-17 17:37:38 发布

转载最新推荐文章于 2025-07-17 17:37:38 发布 · 245 阅读

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package com.file;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class dowLoad extends HttpServlet {

/**
* Constructor of the object.
*/
public dowLoad() {
super();
}

/**
* Destruction of the servlet. 
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

/**
* The doGet method of the servlet. 
*
* This method is called when a form has its tag value method equals to get.
*
* @param request
* the request send by the client to the server
* @param response
* the response send by the server to the client
* @throws ServletException
* if an error occurred
* @throws IOException
* if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html");
// 获得请求文件名
String filename = request.getParameter("filename");
filename = new String(filename.getBytes("iso8859-1"),"UTF-8");
System.out.println(filename);

// 设置文件MIME类型
response.setContentType(getServletContext().getMimeType(filename));
// 设置Content-Disposition
response.setHeader("Content-Disposition", "attachment;filename="+ filename);
// 读取目标文件，通过response将目标文件写到客户端
// 获取目标文件的绝对路径
String fullFileName = getServletContext().getRealPath("/WEB-INF/upload/" + filename);
System.out.println(fullFileName);
// 读取文件
InputStream in = new FileInputStream(fullFileName);
OutputStream out = response.getOutputStream();

// 写文件
int b;
while ((b = in.read()) != -1) {
out.write(b);
}

in.close();
out.close();
}

/**
* The doPost method of the servlet. 
*
* This method is called when a form has its tag value method equals to
* post.
*
* @param request
* the request send by the client to the server
* @param response
* the response send by the server to the client
* @throws ServletException
* if an error occurred
* @throws IOException
* if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html");
this.doHead(request,response);

}

/**
* Initialization of the servlet. 
*
* @throws ServletException
* if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}

}

<%@ page language="java" import="java.util.*" contentType="text/html; charset=UTF-8" pageEncoding="utf-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<%
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>My JSP 'listfile.jsp' starting page</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">


</head>
<body>
 
<c:forEach var="me" items="${fileNameMap}">
<c:url value="servlet/dowLoad" var="downurl">
<c:param name="filename" value="${me.key}"></c:param>
</c:url>
${me.value}<a href="${downurl}" target="_blank">文件下载</a>
 
</c:forEach>
</body>
</html>