[Spring Boot] 22. 스프링부트 뱅크 v1 (4) 기능 설계

1. @RequestParam == req.getParameter()

2. DTO 클래스로 받아오기

1. 회원가입

1. UserRequest

package com.metacoding.bankv1.user;

import lombok.Data;

public class UserRequest {

    @Data
    public static class JoinDTO {
        private String username;
        private String password;
        private String fullname;
    }

    @Data
    public static class LoginDTO {
        private String username;
        private String password;
    }

}

2. UserController

package com.metacoding.bankv1.user;

import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;

@RequiredArgsConstructor
@Controller
public class UserController {

    private final UserService userService;

    @GetMapping("/login-form")
    public String loginForm() {
        return "user/login-form";
    }

    @GetMapping("/join-form")
    public String joinForm() {
        return "user/join-form";
    }

    @PostMapping("/join")
    public String join(UserRequest.JoinDTO joinDTO) {
        // System.out.println(joinDTO); // toString()이 실행됨
        userService.회원가입(joinDTO); // joinDTO 안에 username, password, fullname
        return "redirect:/login-form";
    }
}

3. UserRepository

package com.metacoding.bankv1.user;

import jakarta.persistence.EntityManager;
import jakarta.persistence.Query;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Repository;

@RequiredArgsConstructor
@Repository
public class UserRepository {

    private final EntityManager em;

    public User findByUsername(String username) {
        Query query = em.createNativeQuery("select * from user_tb where username = ?", User.class);
        query.setParameter(1, username);
        try {
            return (User) query.getSingleResult();
        } catch (Exception e) {
            return null;
        }
    }

    public void save(String username, String password, String fullname) { // client로부터 받은 것들 (주소 or body)
        Query query = em.createNativeQuery("insert into user_tb(username, password, fullname, created_at) values (?, ?, ?, now())");
        query.setParameter(1, username);
        query.setParameter(2, password);
        query.setParameter(3, fullname);
        query.executeUpdate();
    }

}

4. UserService

package com.metacoding.bankv1.user;

import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@RequiredArgsConstructor
@Service
// 기능을 정리하면 여기에 전부 다 있다.
public class UserService {
    private final UserRepository userRepository;
    
    @Transactional
    public void 회원가입(UserRequest.JoinDTO joinDTO) {
        // 1. 동일 유저 네임 있는지 검사
        User user = userRepository.findByUsername(joinDTO.getUsername());
        // 2. 있으면, exception 터트리기 (오류는 그 자리에서 터트려야 한다. 리턴X -> 따로 잡아채서 처리)
        if (user != null) throw new RuntimeException("동일한 username이 존재합니다.");
        // 3. 없으면 회원가입하기
        userRepository.save(joinDTO.getUsername(), joinDTO.getPassword(), joinDTO.getFullname());
    }
}

문제점