JAVA防止盗链的小demo

 package cn.edu.Request;


 import java.io.IOException;
 import java.io.PrintWriter;


 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 //防盗链
 public class RequestDemo9 extends HttpServlet {


     public void doGet(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {
         response.setCharacterEncoding("UTF-8");
         response.setContentType("text/html;charset=UTF-8");

         //得到来访地址
         String referer=request.getHeader("referer");

         if(referer==null||!referer.startsWith("http://localhost")){
             //此处为盗链的情况，这个时候要让用户去主页(或其他页面，让用户看广告或其它。。。。)
             response.sendRedirect("/day06/index.jsp");
             return;
         }

         String data="机密文档";
         response.getWriter().write(data);

     }


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


 }