javaweb之request获取referer请求头实现防盗链

package 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;

//利用referer请求头实现防盗链
public class RequestDemo8 extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 获取请求是从哪里来的
String referer = request.getHeader("referer");
// 如果是直接输入的地址，或者不是从本网站访问的重定向到本网站的首页
if (referer == null || !referer.startsWith("http://localhost")) {
response.sendRedirect("/day06/index.jsp");
// 然后return，不要输出后面的内容了
return;
}
String date = "日记";
response.getWriter().write(date);
}

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

}