1.login @PostMapping loginRe(id, pw) service.signIn(aop.SignControllerAspect) -> return String if(id & !pw) = id_ok if(id & pw) = all_ok if(!id) = id_fail 2.join @PostMapping save(user, nickname) <- One To One Table service.signUp(aop.SignControllerAspect) -> not return transaction will be add.... maybe