The reference code [spring-boot] spring-boot project, implement the login function by thymleaf, here is a login interceptor

When we realize login pages, you need web pages protection (access control), there will be no request interceptors are not logged out of the system, this can be achieved through a function of the interceptor

The following are LoginHanderInterceptor.java reference code:

package com.springboot.conponent;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/ ** 
 * @author zhuhonggen
 * @Version Created: 2019/08/06 21:57
 * @ClassName class name
 * @Description class description
 */

public class LoginHanderInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        Object user = request.getSession().getAttribute("loginUser");
        if (user == null ){
            request.setAttribute ( "msg", "You do not have permission!" );
            request.getRequestDispatcher("/login.html").forward(request,response);
            return false;
        }else{
            return false;
        }

    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}