javaweb之打开一个页面，以附件的形式进行下载一个文件（原码）

package cn.itcast.servlet;

import java.io.FileInputStream;
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;

/**
 * Servlet implementation class Download
 */
@WebServlet("/Download")
public class Download extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Download() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//获取图片的路径
		String path=getServletContext().getRealPath("/image/1.jpg");
		//获取输入流
		InputStream in=new FileInputStream(path);
		//设置头以附件的形式，如果不设置的话他就直接显示了
		response.setHeader("Content-Disposition", "attachment;filename=1.jpg");
		//获取输出流
		ServletOutputStream out=response.getOutputStream();
		byte[] b=new byte[1024];
		int len=0;
		//读写操作
		while((len=in.read(b))!=-1){
			out.write(b,0,len);
		}
		in.close();
		out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}