[spring blog]2. User Entity 생성, 회원 가입

package shop.mtcoding.blog.user;

import jakarta.persistence.*;
import lombok.Data;

import java.time.LocalDateTime;

// user로 테이블명을 만들면, 키워드여서 안만들어질 수 있다. _tb 컨벤션 지키자.
@Table(name="user_tb")
@Data
@Entity
public class User {
    @Id // PK 설정
    @GeneratedValue(strategy = GenerationType.IDENTITY) // auto_increment 전략
    private int id;
    private String username;
    private String password;
    private String email;

    // 카멜 표기법으로 만들면 DB는 created_at 으로 만들어진다. (언더스코어 기법)
    private LocalDateTime createdAt;
}

{{> layout/header}}

<div class="container p-5">

    <div class="card">
        <div class="card-header"><b>회원가입을 해주세요</b></div>
        <div class="card-body">
            <form action="/join" method="post" enctype="application/x-www-form-urlencoded"> /join 식별자요청, db변경하기때문에 post요청 xform
                <div class="mb-3">
                    <input type="text" class="form-control" placeholder="Enter username" name="username"> // name 뒤 유저네임
                </div>
                <div class="mb-3">
                    <input type="password" class="form-control" placeholder="Enter password" name="password"> // name 뒤 비밀번호
                </div>
                <div class="mb-3">
                    <input type="email" class="form-control" placeholder="Enter email" name="email"> // name 뒤 이메일
                </div>
                <button type="submit" class="btn btn-primary form-control">회원가입</button>
            </form>
        </div>
    </div>
</div>

{{> layout/footer}}

@Controller
public class UserController {

    @PostMapping("/join")
    public String join() {
        return "redirect:/loginForm";
    }

package shop.mtcoding.blog.user;

import lombok.Data;

public class UserRequest {

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

@PostMapping("/join")
    public String join(UserRequest.JoinDTO requestDTO) {
        System.out.println(requestDTO);
        return "redirect:/loginForm";
    }

String username = request.getParameter("username");

join(String username){}

join(DTO){}

package shop.mtcoding.blog.user;

import jakarta.persistence.EntityManager;
import jakarta.persistence.Query;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;


@Repository // IoC에 new하는 방법
public class UserRepository {

    // DB에 접근할 수 있는 매니저 객체
    // 스프링이 만들어서 IoC에 넣어둔다.
    // DI에서 꺼내 쓰기만 하면된다.
    private EntityManager em;

    // 생성자 주입 (DI 코드)
    public UserRepository(EntityManager em) {
        this.em = em;
    }

    @Transactional // db에 write 할때는 필수
    public void save(UserRequest.JoinDTO requestDTO){
        Query query = em.createNativeQuery("insert into user_tb(username, password, email, created_at) values(?,?,?, now())");
        query.setParameter(1, requestDTO.getUsername());
        query.setParameter(2, requestDTO.getPassword());
        query.setParameter(3, requestDTO.getEmail());
        query.executeUpdate();
    }
}

@PostMapping("/join")
    public String join(UserRequest.JoinDTO requestDTO) {
        System.out.println(requestDTO);
        
        userRepository.save(requestDTO);
        return "redirect:/loginForm";
    }