java中一个简单的下载示例

package com.down;

import java.io.IOException;
import java.io.InputStream;

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;

@WebServlet(
name="download",
urlPatterns={"/test"}
)
public class DownLoad extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doGet(req, resp);
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("application/msword");
response.addHeader("Content-disposition","attachment;filename=test.doc");
InputStream in=getServletContext().getResourceAsStream("/doc/test.doc");
ServletOutputStream os=response.getOutputStream();
byte[] bytes=new byte[1024];
int len=-1;
while((len=in.read(bytes))!=-1){
os.write(bytes,0,len);
}
in.close();
os.close();
}
}