有关servlet实现文件下载

废话不多说，上代码

package com.mlq.servlet;

import com.sun.net.httpserver.HttpsServer;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLEncoder;

public class ServletReponseDFile extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//            § 获取现在文件的路径
//            § 下载的文件名
//            § 设置让浏览器支持我们需要的下载的东西，让URLEncoder.encode编码，否则可能乱码
//            § 获取下载文件的输入流
//            § 创建缓冲区
//            § 获取OutputStream对象
//            § =将FileOutputStream流写入到buffer缓冲区
//          使用OutputStream，将缓冲区中的数据输出到客户端中
        String realPath="D:/Javacode/servletWebappDemo2/servletWebappDemo2/src/main/resources/1.jpg";
        String filename=realPath.substring(realPath.lastIndexOf("/")+1);
        resp.setHeader("Content-Disposition", "attachment; filename="+ URLEncoder.encode(filename,"utf-8"));
        FileInputStream in=new FileInputStream(realPath);
        byte[] bytes=new byte[1024];
        int len=0;
        ServletOutputStream out = resp.getOutputStream();
        while ((len=in.read(bytes))>0){
            out.write(bytes,0,len);
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }
}