JSP与Servlet实现文件下载-优快云博客

本文链接：https://blog.youkuaiyun.com/scbiaosdo/article/details/81541781

一、jsp代码

<html>
<head>
    <title></title>
</head>
<body>
<a href="./download">下载</a>
</body>
</html>

二、servlet代码

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLEncoder;

@WebServlet(name = "downloadServlet")
public class downloadServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //获取系要下载的文件
        File file = new File("D:\\下载\\BaiduNetdisk_6.2.0.exe");

        //获得输出流
        OutputStream os = response.getOutputStream();

        //获得文件扩展名
        String extfilename = FilenameUtils.getExtension("D:\\下载\\BaiduNetdisk_6.2.0.exe");

        //指定文件下载名 并指定编码格式
        response.setHeader("Content-disposition","attachment;filename="+ URLEncoder.encode("百度云盘."+extfilename,"utf-8"));


        //将文件写到输出流
        IOUtils.copy(new FileInputStream(file),os);
        //刷新流
        os.flush();
        //关闭流
        os.close();
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doPost(request,response);

    }
}

三、xml配置

    <servlet>
        <servlet-name>downloadServlet</servlet-name>
        <servlet-class>downloadServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>downloadServlet</servlet-name>
        <url-pattern>/download</url-pattern>
    </servlet-mapping>

jsp中的文件下载