Spring MVC实现文件下载

文件下载的含义十分简单，它指的就是将服务器中的文件下载到本机上。

一、在之前Spring MVC文件上传中和跨服务器保存文件 项目中操作

在WEB-INF/templates下创建一个download.html 的代码，在图片旁边添加一个文件下载的超链接代码如下：

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Title</title>
    <style>
        #playerTable{
            width: 50%;
            border: 3px solid cadetblue;
            margin: 0px auto;
            text-align: center;
        }
        #playerTable th,td{
            border: 1px solid gray;
        }
        #playerTable img{
            width: 100px;
            height: 100px;
        }
    </style>
    <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js" type="text/javascript"></script>
    <script>
        $(function(){
            $.ajax({
                type:"get",
                url:"getAllPlayer",//请求后端的地址，获取查出来的结果
                success:function(players){
                    $.each(players,function(i,e){
                        $("#playerTable").append('<tr>\n' +
                            '        <td>'+e.id+'</td>\n' +
                            '        <td>'+e.username+'</td>\n' +
                            '        <td>'+e.password+'</td>\n' +
                            '        <td>'+e.nickname+'</td>\n' +
                            '        <td>\n' +
                            '            <img src="http://192.168.141.134:8080/upload/'+e.photo+'" alt="" src>\n' +
                            '        </td>\n' +
                            '        <td>\n' +
                            '            <a href="fileDownload.do?photo='+e.photo+'&filetype='+e.filetype+'">下载</a>\n' +
                            '        </td>\n' +
                            '    </tr>')
                    })
                }
            })
        })
    </script>
</head>
<body>
<table id="playerTable" cellspacing="0xp" cellpadding="0px">
    <tr>
        <th>编号</th>
        <th>用户名</th>
        <th>密码</th>
        <th>昵称</th>
        <th>头像</th>
        <th>操作</th>
    </tr>
</table>
</body>
</html>

二、在mapper层进行操作

在PlayerMapper中添加如下内容：

package com.augus.mapper;

import com.augus.pojo.Player;

import java.util.List;

public interface PlayerMapper {
    int addUser(Player player);

　　 //查询出表中所有的信息
    List<Player> getAllPlayer();
}

在PlayerMapper.xml中添加如下内容：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.augus.mapper.PlayerMapper">
    <insert id="addUser">
        insert into player values(DEFAULT ,#{username},#{password},#{nickname},#{photo},#{filetype})
    </insert>
    <!--查询表中所有的数据-->
    <select id="getAllPlayer" resultType="Player">
        select * from player
    </select>
</mapper>

三、在service层进行操作

在PlayerService添加获取所有信息的接口

package com.augus.service;

import com.augus.pojo.Player;

import java.util.List;

public interface PlayerService {
    int addUser(Player player);

    List<Player> getAllPlayer();
}

在PlayerService添加获取所有信息的接口

package com.augus.service.impl;

import com.augus.mapper.PlayerMapper;
import com.augus.pojo.Player;
import com.augus.service.PlayerService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

@Service
public class PlayerServiceImpl implements PlayerService {
    //这个本来@Autowired保存，所以改用@Resource
    @Resource
    private PlayerMapper playerMapper;

    @Override
    public int addUser(Player player) {
        return playerMapper.addUser(player);
    }
    
    //列出所有的数据
    @Override
    public List<Player> getAllPlayer() {
        return playerMapper.getAllPlayer();
    }
}

四、在controller层进行操作

在FileUploadController 添加一下代码实现文件下载

package com.augus.controller;


import com.augus.pojo.Player;
import com.augus.service.PlayerService;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.WebResource;
import org.apache.commons.io.IOUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;

@Controller
public class FileUploadController {
    //文件存储位置,定为私有不可修改的静态属性
    private final static String FILESERVER = "http://192.168.141.134:8080/upload/";

    @Autowired
    private PlayerService playerService;

　　 //打开文件下载页面
    @RequestMapping("/playerAllList")
    public String playerAllList(){
        return "download";
    }
    
    //异步请求会调用这个地址，将从数据库查出的数据返回给前端页面
    @RequestMapping("/getAllPlayer")
    @ResponseBody
    public List<Player> getAllPlayer(){
        return playerService.getAllPlayer();
    }
    
    //实现下载文件
    @RequestMapping("/fileDownload.do")
    public void fileDownLoad(String photo, String fileType, HttpServletResponse response) throws IOException {
        //设置响应头
        // 指定浏览器下载下的数据保存到磁盘上面，不要在浏览器之间解析
        response.setHeader("Content-Disposition","attachment;filename="+photo);
        //告诉浏览器下载的文件类型
        response.setContentType(fileType);

        //获取一个文件的输入流
        InputStream inputStream = new URL(FILESERVER + photo).openStream();

        //获取一个指向浏览器的输出流
        ServletOutputStream outputStream = response.getOutputStream();
        //向浏览器响应文件即可
        IOUtils.copy(inputStream,outputStream);
    }
}

五、重新部署Tomcat

访问地址http://localhost:8080/upfile_war_exploded/playerAllList，如下：

posted @ 2019-10-28 10:14  酒剑仙*  阅读(3001)  评论(0)    收藏  举报