DTO, API 작성. User 엔티티 필드 순서 수정

src/main/java/com/sc/secondHandMarket/TestUserDataInit.java

@@ -0,0 +1,38 @@
+package com.sc.secondHandMarket;
+
+import com.sc.secondHandMarket.domain.user.entity.User;
+import com.sc.secondHandMarket.domain.user.repository.UserRepository;
+import jakarta.annotation.PostConstruct;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+/**
+ *  User 데이터 넣는 코드
+ *
+ *  주석화 해놓은 @Component와 @PostConstruct를 주석화 헤제한 뒤
+ *  메인 코드를 실행시키면 자동으로 들어감.
+ *
+ *  이후에는 다시 두 어노테이션을 주석화할 것.
+ *
+ *  * 마음대로 더 추가 가능
+ */
+
+//@Component
+@RequiredArgsConstructor
+public class TestUserDataInit {
+
+    private final UserRepository userRepository;
+
+//    @PostConstruct
+    public void testUserData() throws InterruptedException {
+        User user1 = new User("user1", "123123", "random1@naver.com", "010-1254-2314");
+        Thread.sleep(1000);
+        User user2 = new User("user2", "456456", "random2@naver.com", "010-1459-0897");
+        Thread.sleep(1000);
+        User user3 = new User("user3", "789789", "random3@naver.com", "010-9854-0283");
+
+        userRepository.save(user1);
+        userRepository.save(user2);
+        userRepository.save(user3);
+    }
+}

src/main/java/com/sc/secondHandMarket/domain/sale/entity/Sale.java

@@ -19,6 +19,7 @@ public class Sale {
     @ManyToOne(fetch= LAZY)
     @JoinColumn(name = "user_id")
     private User user;
+
     @ManyToOne(fetch = LAZY)
     @JoinColumn(name = "product_id")
     private Product product;

src/main/java/com/sc/secondHandMarket/domain/user/controller/UserController.java

@@ -1,7 +1,45 @@
 package com.sc.secondHandMarket.domain.user.controller;
 
-import org.springframework.stereotype.Controller;
+import com.sc.secondHandMarket.domain.user.dto.request.UserRequestDto;
+import com.sc.secondHandMarket.domain.user.dto.response.UserResponseDto;
+import com.sc.secondHandMarket.domain.user.service.UserService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
 
-@Controller
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/users")
+@RequiredArgsConstructor
 public class UserController {
+
+    private final UserService userService;
+
+    // 전체 User 조회
+    @GetMapping
+    public ResponseEntity<List<UserResponseDto>> findAll() {
+        return ResponseEntity.ok(userService.findAll());
+    }
+
+    // ID로 User 조회
+    @GetMapping("/{userId}")
+    public ResponseEntity<UserResponseDto> findById(@PathVariable Long userId) {
+        return ResponseEntity.ok(userService.findById(userId));
+    }
+
+    // User 저장
+    @PostMapping
+    public ResponseEntity<String> saveUser(@RequestBody UserRequestDto userDto) {
+        userService.save(userDto.toUser());
+        return ResponseEntity.ok("User saved");
+    }
+
+    //ID로 User 삭제
+    @DeleteMapping("/{userId}")
+    public ResponseEntity<String> deleteUser(@PathVariable Long userId) {
+        userService.deleteById(userId);
+        return ResponseEntity.ok("User deleted");
+    }
+
 }

src/main/java/com/sc/secondHandMarket/domain/user/dto/request/UserRequestDto.java

@@ -0,0 +1,23 @@
+package com.sc.secondHandMarket.domain.user.dto.request;
+
+import com.sc.secondHandMarket.domain.user.entity.User;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class UserRequestDto {
+    private String nickname;
+    private String password;
+    private String email;
+    private String phone;
+
+    public User toUser() {
+        return new User(
+                nickname,
+                password,
+                email,
+                phone);
+    }
+
+}

src/main/java/com/sc/secondHandMarket/domain/user/dto/response/UserResponseDto.java

@@ -0,0 +1,24 @@
+package com.sc.secondHandMarket.domain.user.dto.response;
+
+import com.sc.secondHandMarket.domain.user.entity.User;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Getter
+@NoArgsConstructor
+public class UserResponseDto {
+
+    private String nickname;
+    private String email;
+    private String phone;
+    private LocalDateTime created_at;
+
+    public UserResponseDto(User user) {
+        this.nickname = user.getNickname();
+        this.email = user.getEmail();
+        this.phone = user.getPhone();
+        this.created_at = user.getCreated_at();
+    }
+}

src/main/java/com/sc/secondHandMarket/domain/user/entity/User.java

@@ -19,16 +19,16 @@ public class User {
     @GeneratedValue
     private Long id;
 
-    private String email;
-    private String password;
     private String nickname;
+    private String password;
+    private String email;
     private String phone;
     private LocalDateTime created_at;
 
-    public User(String email, String password, String nickname, String phone) {
-        this.email = email;
-        this.password = password;
+    public User(String nickname, String password, String email, String phone) {
         this.nickname = nickname;
+        this.password = password;
+        this.email = email;
         this.phone = phone;
         this.created_at = LocalDateTime.now();
     }

src/main/java/com/sc/secondHandMarket/domain/user/service/UserService.java

@@ -1,7 +1,16 @@
 package com.sc.secondHandMarket.domain.user.service;
 
-import org.springframework.stereotype.Service;
+import com.sc.secondHandMarket.domain.user.dto.response.UserResponseDto;
+import com.sc.secondHandMarket.domain.user.entity.User;
 
-@Service
-public class UserService {
+import java.util.List;
+
+public interface UserService {
+    List<UserResponseDto> findAll();
+
+    UserResponseDto findById(Long userId);
+
+    User save(User user);
+
+    User deleteById(Long userId);
 }

src/main/java/com/sc/secondHandMarket/domain/user/service/UserServiceImpl.java

@@ -0,0 +1,48 @@
+package com.sc.secondHandMarket.domain.user.service;
+
+import com.sc.secondHandMarket.domain.user.dto.response.UserResponseDto;
+import com.sc.secondHandMarket.domain.user.entity.User;
+import com.sc.secondHandMarket.domain.user.repository.UserRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class UserServiceImpl implements UserService{
+
+    private final UserRepository userRepository;
+
+    @Override
+    public List<UserResponseDto> findAll() {
+        List<UserResponseDto> dtoList = new ArrayList<>();
+        for (User user : userRepository.findAll()) {
+            dtoList.add(toDto(user));
+        }
+        return dtoList;
+    }
+
+    @Override
+    public UserResponseDto findById(Long userId) {
+        return toDto(userRepository.findById(userId).orElseThrow());
+    }
+
+    @Override
+    public User save(User user) {
+        return userRepository.save(user);
+    }
+
+    // DTO로 변환
+    private UserResponseDto toDto(User user) {
+        return new UserResponseDto(user);
+    }
+
+    @Override
+    public User deleteById(Long userId) {
+        User user = userRepository.findById(userId).orElseThrow();
+        userRepository.deleteById(userId);
+        return user;
+    }
+}