Login interceptor

Myconfig.java

@Component
public class MyConfig implements WebMvcConfigurer {
    
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
    
        registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/**").excludePathPatterns("/","/user","/login","/echarts/**","/img/**","/layui/**","/login.html","/code");
    }
}

LoginInterceptor

public class LoginInterceptor 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"," No authority , Please log in first !");
            request.getRequestDispatcher("/login").forward(request,response);
            return false;
        }else{
    
            return true;
        }
    }
}

LoginController

//  Check the legitimacy of login user identity 
    @RequestMapping("/user")
    public String user(@RequestParam("username") String username,
                       @RequestParam("password") String password,
                       @RequestParam("captcha") String captcha,Model model, HttpSession session,HttpServletRequest request){
    
        session = request.getSession();
        String code = (String) session.getAttribute("code");
        System.out.println(code);
        System.out.println(captcha);
        if(!captcha.equalsIgnoreCase(code.trim())){
    
            model.addAttribute("msg"," Verification code error ");
            return "login";
        }
        Map<String,Object> mp = new HashMap<>();
        mp.put("username",username); mp.put("password",password);
        List<User> list = loginService.checkuser(mp);
        if(list.size()>0){
    
            session.setAttribute("loginUser",username);
            return "index";
        }else{
    
            model.addAttribute("msg"," Wrong account or password ");
            return "login";
        }
    }