案例_文件下载_中文文件问题和会话技术_概述

问题：

　　中文文件问题

　　　　解题思路

　　　　　　获取客户端使用的浏览器版本信息　　

　　　　　　根据不同的版本信息，设置filname的编码方式不同

@WebServlet("/downloadloadServlet")
public class ServletContextDemo5 extends HttpServlet {

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

        String filename = req.getParameter("filename");

        ServletContext servletContext = this.getServletContext();
        String realPath = servletContext.getRealPath("/ass/" + filename);
        FileInputStream fileInputStream = new FileInputStream(realPath);


        String mimeType = servletContext.getMimeType(filename);
        resp.setHeader("content-type",mimeType);

        String header = req.getHeader("user-agent");
        filename = DownLoadUtils.getFileName(header,filename);


        resp.setHeader("content-disposition","attachment;filename="+filename);

        ServletOutputStream outputStream = resp.getOutputStream();
        byte[] bytes = new byte[1024];

        int len = 0;
        while ((len = fileInputStream.read(bytes))!= -1){
            outputStream.write(bytes,0,len);
        }

        fileInputStream.close();
        outputStream.close();

    }

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

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <a href="/ass/狼.jpg">图片</a>
    <a href="/ass/bna.mp4">视频</a>

    <a href="/downloadloadServlet?filename=狼.jpg">图片1</a>

    <a href="/downloadloadServlet?filename=bna.mp4">视频1</a>
</body>
</html>