防盗链

使用防盗链要使用request的referer这个头，这个头可以截获用户是从哪个页面点过来的，然后判断是否为本站的地址，如果不是本站的地址，就跳转到本站首页

package cn.test.request; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; //防盗链 http://localhost:8080/day06/servlet/ResponseDemo4 public class RequestDemo4 extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //referer头获取用户访问的URL地址 String referer = request.getHeader("referer"); if(referer==null || !referer.startsWith("http://localhost")){ response.sendRedirect("/day05/index.html"); return; } String data = "日记"; response.getWriter().write(data); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }