文件下载

　　

package com.zhengyizhan.Controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

/**
 * Created by Administrator on 2019-09-20.
 */
@Controller
public class DownloadController {
    /**
     * 文件下载
     * @throws IOException
     */
    @RequestMapping(value="/download",method= RequestMethod.GET)
    public void download(@RequestParam(value="filename")String filename,
                         HttpServletRequest request,
                         HttpServletResponse response) throws IOException {
        //模拟文件，myfile.txt为需要下载的文件
        String path = request.getSession().getServletContext().getRealPath("WEB-INF\jsp\upload")+"\"+filename;
        //获取输入流
        InputStream bis = new BufferedInputStream(new FileInputStream(new File(path)));
        //转码，免得文件名中文乱码
        filename = URLEncoder.encode(filename,"UTF-8");
        //设置文件下载头
        response.addHeader("Content-Disposition", "attachment;filename=" + filename);
        //1.设置文件ContentType类型，这样设置，会自动判断下载文件类型
        response.setContentType("multipart/form-data");
        BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
        int len = 0;
        while((len = bis.read()) != -1){
            out.write(len);
            out.flush();
        }
        out.close();
    }
}