SpringBoot login user permission interceptor

1. Create a custom interceptor class and implement HandlerInterceptorthe interface

package com.xgf.online_mall.interceptor;

import com.xgf.online_mall.system.domain.User;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.SimpleFormatter;

@Slf4j
@Component
public class UserLoginAuthInterceptor implements HandlerInterceptor {
    
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    
    
        log.info(" ======== UserAuthInterceptor preHandle 登录权限拦截器拦截");
        User user = (User) request.getSession().getAttribute("loginUser");
        //未登录才判断，登录了直接放行
        if(user == null){
    
    
            //获取访问路径
            String address = request.getRequestURI();
            log.info("======== 拦截，访问路径 address : {}", address);
            response.sendRedirect(request.getContextPath() + "/login.html");
            return false;

            /*String address = request.getRequestURI();
            log.info("======== 拦截，访问路径 address : {}", address);
            //不是登录或者注册页面，就直接跳转登录界面
            if(!address.contains("login") && !address.contains("register")){
                //强制到登录页面
                response.sendRedirect(request.getContextPath() + "/login.html");
                //设置为false，不访问controller
                return false;
            }*/
        }
        //其它模块或者已经登录，就直接放行
//        log.info("======== 已登录 user = {}", user);
        return true;
    }


    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    
    
        log.info(" ===== UserAuthInterceptor postHandle");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    
    
        log.info("==== UserAuthInterceptor afterCompletion");

        //记录日志  向文件里面写日志
        //获取服务器记录日志log文件所存放的目录位置 -- tomcat下的真实路径+log目录
        String logdir = request.getServletContext().getRealPath("log");
        //路径不存在就创建
        Path logdirPath = Paths.get(logdir);
        if(Files.notExists(logdirPath)){
    
    
            Files.createDirectories(logdirPath);
        }
        //目录存在就将数据[字符]写入 //存放日志的路径+文件名
        Path logfile = Paths.get(logdir,"userlog.log");
        //logfile.toFile() paths转换为File类型 true以追加的方式写入
        BufferedWriter writer = new BufferedWriter(new FileWriter(logfile.toFile(),true));

        //获取登录用户信息
        User user = (User)request.getSession().getAttribute("loginUser");
        //记录user信息，存入日志
        writer.write(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + " >> " + user +"\r\n");
        writer.flush();
        writer.close();
    }

}

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2. Create a WebMvcConfigurer interface implementation class, register and take effect of the custom interceptor

import com.xgf.online_mall.constant.PathConstantParam;
import com.xgf.online_mall.interceptor.UserLoginAuthInterceptor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.util.ArrayList;
import java.util.List;

@Configuration
@Slf4j
public class LoginConfig implements WebMvcConfigurer {
    
    
    @Autowired
    private UserLoginAuthInterceptor userLoginAuthInterceptor;

    /**
     * addInterceptors方法设置拦截路径
     *      addPathPatterns：需要拦截的访问路径
     *      excludePathPatterns：不需要拦截的路径，
     *      String数组类型可以写多个用","分割
     * @param registry
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry){
    
    
        log.info(" ======== LoginConfig.addInterceptors");
        //添加对用户未登录的拦截器，并添加排除项
        //error路径，excludePathPatterns排除访问的路径在项目中不存在的时候，
        //springboot会将路径变成 /error, 导致无法进行排除。
        registry.addInterceptor(userLoginAuthInterceptor)
                .addPathPatterns("/**")
                .excludePathPatterns("/js/**", "/css/**", "/img/**", "/plugins/**")
                .excludePathPatterns("/login.html", "/register.html", "/system/user/login", "/system/user/login", "/index")
                .excludePathPatterns("/error");
    }
}