Use ajax to jump to the login page after session timeout

This time I will bring you how to use ajax to jump to the login page when the session times out, and use ajax to jump to the login page when the session times out. What are the precautions? The following is a practical case, let's take a look one time.

Problem: When using window.location.href to jump to the page, the backend only needs to implement a

filter to redirect to the login page when the session times out. But what about using ajax? Using ajax to execute will result in a 302 error and it is impossible to jump to the page. Below I will post my front-end and back-end code to address this issue.

1. Session filter

import java.io.IOException;
<p style="text-align: center"><img alt=""import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
<p style="text-align: center"><img alt=""public class SessionFilter implements Filter {
<p style="text-align: center"><img alt="" public void doFilter(ServletRequest req, ServletResponse res, FilterChain filterChain)
   throws IOException, ServletException {
  HttpServletRequest request = (HttpServletRequest) req;
  HttpServletResponse response = (HttpServletResponse) res;
<p style="text-align: center"><img alt=""  String requestUri = request.getRequestURI();
<p style="text-align: center"><img alt=""  if (requestUri.indexOf("/login.html") > 0 || requestUri.indexOf("/system/login") > 0) {
   return ;
  }
<p style="text-align: center"><img alt=""  HttpSession session = request.getSession(false);
<p style="text-align: center"><img alt=""  if (session == null) {
   // 如果是session超时，在此处做处理。
   response.sendRedirect(request.getContextPath() + "/login.html");
   return ;
  }
  try {
   filterChain.doFilter(request, response);
  } catch (Exception e) {
   e.printStackTrace();
  }
  return ;
 }
}

2. Add configuration to web.xml:

<filter>
  <filter-name>sessionFilter</filter-name>
  <filter-class>com.manager.filter.SessionFilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>sessionFilter</filter-name>
  <url-pattern>/manager/*</url-pattern>
</filter-mapping>

*3 , Rewrite ajax

Note: This code is placed on the index page

jQuery(function($){
   var _ajax=$.ajax;
   $.ajax=function(opt){
    var _success = opt && opt.success || function(a, b){};
    var _opt = $.extend(opt, {
     success:function(data, textStatus){
      _success(data, textStatus); 
     },
     error:function(XMLHttpRequest, textStatus, errorThrown){
      //alert(XMLHttpRequest.responseText);
      //如果请求发生错误，会返回登陆页面源代码，如果源代码里面存在lovnx这个字符串，前端就重定向到登陆页面
      var reData = XMLHttpRequest.responseText + "";
      if(reData.indexOf('lovnx') != -1) {
       window.location.href="/manager/login.html" rel="external nofollow" ;
       return;
      }
     }
    });
    return _ajax(_opt);
   };
  });

4. Add code to the login page

<input type="hidden" value="lovnx">

Believe it or not After reading the case in this article, you have mastered the method. For more exciting information, please pay attention to other related articles on the PHP Chinese website!

Recommended reading:

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Ajax-based formData image and data upload rue implementation

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