response读取图片+下载图片

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

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


public class OutServlet extends HttpServlet {


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

                  String url = this.getContext().getRealPath("test.jpg");
                  InputStream in = new FileInputStream(url);
                  OutputStream out = response.getOutputStream();
		  byte [] by = new by[1024];
                  int i = 0;
                  while((i=in.read(by))!=-1)
                 {
                      
                         out.write(by,0,i);

                  }
                   in.close();
	
	}


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

		doGet(request,response);
	}

}
                      
import java.io.FileInputStream;
impor