springboot拦截器-含模板引擎Thymeleaf-小demo

0、persion实体类

package com.jf3q.study.bean;

import lombok.Data;
import lombok.ToString;
import org.springframework.stereotype.Component;


@Component
@ToString
@Data
public class Persion {
    private  int id ;
    private  String username;
    private  String password;

}

1、登陆页面:

2、control层

package com.jf3q.study.control;

import com.jf3q.study.bean.Persion;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;

import javax.servlet.http.HttpSession;

@Controller
public class LoginControl {


    @PostMapping("/login")
    public  String login(Persion persion, Model model, HttpSession session){
        System.out.println(persion.getPassword());
        if(!persion.getPassword().equals("123456")){
            //提示密码错误
            model.addAttribute("mess","密码错误");
            //页面不跳转

            return "login";
        }else {
            session.setAttribute("loginUser",persion);
            //防止表单重复提交
            return "redirect:/main.html";
        }

    }
    @GetMapping("/main.html")
    public  String main(){
        return "main";
    }
}

3、拦截器

package com.jf3q.study.control.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;

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

public class LoginInterceptor implements HandlerInterceptor {


    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        HttpSession session=request.getSession();
        Object loginUser = session.getAttribute("loginUser");
        if(loginUser ==null){
            //拦截
            request.setAttribute("mess","请先登陆");
            request.getRequestDispatcher("/").forward(request,response);//转发到登陆页面
            return false;
        }
        //放行
        return true;
    }
}

4、注册拦截器

package com.jf3q.study.config;

import com.jf3q.study.control.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceptor())
                .addPathPatterns("/**") //所有请求都被拦截，包括静态资源
                .excludePathPatterns("/","/login","/img/**","/js/**","/css/**");//设置不拦截的路径
    }
}

5、登陆成功的页面

效果：

有什么不懂的可以q我1913284695