jsp_实现文件下载功能

package MyWeb.java;

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

import javax.imageio.stream.FileImageInputStream;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.ws.Response;

public class Download extends HttpServlet {

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

//String path = this.getServletContext().getRealPath("/download/8.jpg"); //置入文件
String path = this.getServletContext().getRealPath("/download/Dj舞曲 - 摇啊摇.mp3");

//1	 response.getWriter().print(path); 1打印出照片的详细地址 //

//实行取得文件名称的工能
int index = path.lastIndexOf(File.separator);
String name= path.substring(index+1);
//	response.getWriter().print(name);

//实行下载功能
//response.setHeader("content-disposition", "attachment;filename = name");
response.setHeader("content-disposition", "attachment;filename="+URLEncoder.encode(name, "utf-8"));//取得文件名的名字

//实行图片下载

InputStream in = new FileInputStream(path);
OutputStream out = response.getOutputStream();
byte[] b = new byte[1024];
int len = 0;
while((len=in.read(b))!=-1){
out.write(b,0,len);
}
in.close();

}

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

doGet(request, response);
}

}

新建一个文件夹：用以存放要本程序要运用的文件。