request 防盗链

package request;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import sun.awt.RepaintArea;

public class RequestDemo7 extends HttpServlet {
    
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String referer = request.getHeader("referer");
        //防盗链
        //判断请求是从哪里过来的，如果不符合要求就跳转到我网站首页上
        if(referer==null || !referer.startsWith("http://localhost")){
            response.sendRedirect("//index.jsp");
            return;//这里一点要return 不然后面的代码还是会执行，我们希望是不执行
        }
        
        String data = "你要看的资源";
        response.getWriter().write(data);
    }

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

}