Redis实现单设备登录的场景分析

@PostMapping("login")
@ApiOperation(value = "用户登录",notes = "用户登录")
public GraceJSONResult login(@RequestParam String userId,HttpServletRequest request) throws Exception {
    String uToken = UUID.randomUUID().toString();
    //把token存入redis
    redis.set("redis_user_token"+":"+userId,uToken);
    //返回用户信息，包含token
    return GraceJSONResult.ok(usersVO);
}

public class BaseInfoProperties {
    @Autowired
    public RedisOperator redis;
}

public class UserTokenInterceptor extends BaseInfoProperties implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String userId = request.getHeader("headerUserId");
        String userToken = request.getHeader("headerUserToken");
        // 判断用户id和token是否为空
        if(StringUtils.isNotBlank(userId) && StringUtils.isNotBlank(userToken)){
            String redisToken=redis.get(REDIS_USER_TOKEN+":"+userId);
            //判断token是否失效
            if(StringUtils.isBlank(redisToken)){
                GraceException.display(ResponseStatusEnum.UN_LOGIN);
                return false;
            }else {
                //判断token是否一致,如果不一致，表示用户在别的手机端登录，token被覆盖了
                if(!redisToken.equalsIgnoreCase(redisToken)){
                    GraceException.display(ResponseStatusEnum.TICKET_INVALID);
                    return false;
                }
            }
        }else {
            // 用户id和token为空
            GraceException.display(ResponseStatusEnum.UN_LOGIN);
            return false;
        }

        return true;
    }
}

@Configuration
public class InterceptorConfig implements WebMvcConfigurer{
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //要拦截的请求，哪些需要登录
        registry.addInterceptor(userTokenInterceptor())
                .addPathPatterns("/userInfo/modifyUserInfo")
                .addPathPatterns("/userInfo/modifyImage");
    }
    //用户未登录拦截器
    @Bean
    public UserTokenInterceptor userTokenInterceptor() {
       return  new UserTokenInterceptor();
    }
}