735~736文件下载代码实现中文文件名问题

问题：
　　中文文件问题
　　　　解决思路：
　　　　　1. 获取客户端使用的浏览器版本信息
　　　　　2. 根据不同的版本信息，设置filename的编码方式不

package com.example.download;

import com.example.utils.DownLoadUtils;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;

@WebServlet("/downloadServlet")
public class DownloadServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.获取请求参数，文件名称
        String filename = request.getParameter("filename");
        //2.使用字节输入流加载文件进内存
        //2.1找到文件服务器路径
        ServletContext servletContext = this.getServletContext();
        String realPath = servletContext.getRealPath("/img/" + filename);
        //2.2用字节流关联
        FileInputStream fis = new FileInputStream(realPath);
        //3.设置response的响应头
        //3.1设置响应头类型：content-type
        String mimeType = servletContext.getMimeType(filename);//获取文件的mime类型
        response.setHeader("content-type",mimeType);
        //3.2设置响应头打开方式:content-disposition
        //解决中文文件名问题
        //1.获取user-agent请求头、
        String agent = request.getHeader("user-agent");
        //2.使用工具类方法编码文件名即可
        filename = DownLoadUtils.getFileName(agent, filename);
        response.setHeader("content-disposition","attachment;filename="+filename);
        //4.将输入流的数据写出到输出流中
        ServletOutputStream sos = response.getOutputStream();
        byte[] buff = new byte[1024 * 8];
        int len = 0;
        while((len = fis.read(buff)) != -1){
            sos.write(buff,0,len);
        }
        fis.close();
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

package com.example.utils;

import sun.misc.BASE64Encoder;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

public class DownLoadUtils {
    public static String getFileName(String agent, String filename) throws UnsupportedEncodingException {
        if (agent.contains("MSIE")) {
            // IE浏览器
            filename = URLEncoder.encode(filename, "utf-8");
            filename = filename.replace("+", " ");
        } else if (agent.contains("Firefox")) {
            // 火狐浏览器
            BASE64Encoder base64Encoder = new BASE64Encoder();
            filename = "=?utf-8?B?" + base64Encoder.encode(filename.getBytes("utf-8")) + "?=";
        } else {
            // 其它浏览器
            filename = URLEncoder.encode(filename, "utf-8");
        }
        return filename;
    }
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <a href="/img/1.jpg">图片1</a>
    <a href="/img/1.avi">视频</a>
    <hr>
    <a href="/downloadServlet?filename=九尾.jpg">图片1</a>
    <a href="/downloadServlet?filename=1.avi">视频</a>
</body>
</html>