使用Servlet实现下载文件的功能

在前台有一个下载链接，比如

<a href="DownLoadServlet">下载</a> <br/>  

使用Servlet实现下载：

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLEncoder;  

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;  

public class DownLoadServlet extends HttpServlet {  

    public DownLoadServlet() {
        super();
    }  

    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }  

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request,response);
    }  

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //处理请求
        //读取要下载的文件
        File f = new File("E:/好久不见.mp3");
        if(f.exists()){
            FileInputStream  fis = new FileInputStream(f);
            String filename=URLEncoder.encode(f.getName(),"utf-8"); //解决中文文件名下载后乱码的问题
            byte[] b = new byte[fis.available()];
            fis.read(b);
            response.setCharacterEncoding("utf-8");
            response.setHeader("Content-Disposition","attachment; filename="+filename+"");
            //获取响应报文输出流对象
            ServletOutputStream  out =response.getOutputStream();
            //输出
            out.write(b);
            out.flush();
            out.close();
        }     

    }  

    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException {
        // Put your code here
    }  

}  

配置文件注意路径。。。