[3주차] 변승현/[feat] 게시글 도메인 API 구현

build.gradle

@@ -33,6 +33,7 @@ dependencies {
     runtimeOnly 'com.mysql:mysql-connector-j'
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
     implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.5.0'
+    implementation 'org.springframework.boot:spring-boot-starter-validation'
 }
 
 tasks.named('test') {

src/main/java/com/example/demo/DemoApplication.java

@@ -2,7 +2,9 @@
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
 
+@EnableJpaAuditing
 @SpringBootApplication
 public class DemoApplication {
 

src/main/java/com/example/demo/controller/PostController.java

@@ -0,0 +1,72 @@
+package com.example.demo.controller;
+
+import com.example.demo.domain.post.dto.*;
+import com.example.demo.domain.post.service.PostService;
+import com.example.demo.global.response.ApiResponse;
+import jakarta.validation.Valid;
+import jakarta.validation.constraints.Min;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+@RequestMapping("/api/posts")
+@RequiredArgsConstructor
+@Validated
+public class PostController {
+
+    private final PostService postService;
+
+    @GetMapping
+    public ResponseEntity<ApiResponse<PostListResponse>> getPosts(
+            @RequestParam(defaultValue = "0") @Min(value = 0, message = "페이지 번호는 0 이상이어야 합니다.") int page,
+            @RequestParam(defaultValue = "10") @Min(value = 1, message = "페이지 크기는 1 이상이어야 합니다.") int size
+    ) {
+        return ResponseEntity.ok(
+                ApiResponse.success("POST_LIST_SUCCESS", "게시글 목록 조회 성공", postService.getPosts(page, size))
+        );
+    }
+
+    @GetMapping("/{postId}")
+    public ResponseEntity<ApiResponse<PostDetailResponse>> getPost(@PathVariable Long postId) {
+        return ResponseEntity.ok(
+                ApiResponse.success("POST_DETAIL_SUCCESS", "게시글 상세 조회 성공", postService.getPost(postId))
+        );
+    }
+
+    @PostMapping
+    public ResponseEntity<ApiResponse<PostCreateResponse>> createPost(
+            @Valid @RequestBody PostCreateRequest request
+    ) {
+        return ResponseEntity.status(HttpStatus.CREATED)
+                .body(ApiResponse.success(
+                        "POST_CREATE_SUCCESS",
+                        "게시글 생성 성공",
+                        postService.createPost(request)
+                ));
+    }
+
+    @PatchMapping("/{postId}")
+    public ResponseEntity<ApiResponse<Void>> updatePost(
+            @PathVariable Long postId,
+            @Valid @RequestBody PostUpdateRequest request
+    ) {
+        postService.updatePost(postId, request);
+        return ResponseEntity.ok(
+                ApiResponse.success("POST_UPDATE_SUCCESS", "게시글이 수정되었습니다.", null)
+        );
+    }
+
+    @DeleteMapping("/{postId}")
+    public ResponseEntity<ApiResponse<Void>> deletePost(
+            @PathVariable Long postId,
+            @Valid @RequestBody PostDeleteRequest request
+    ) {
+        postService.deletePost(postId, request);
+        return ResponseEntity.ok(
+                ApiResponse.success("POST_DELETE_SUCCESS", "게시글이 삭제되었습니다.", null)
+        );
+    }
+}

src/main/java/com/example/demo/domain/post/dto/PageInfoResponse.java

@@ -0,0 +1,10 @@
+package com.example.demo.domain.post.dto;
+
+public record PageInfoResponse(
+        int page,
+        int size,
+        long totalElements,
+        int totalPages,
+        boolean hasNext
+) {
+}

src/main/java/com/example/demo/domain/post/dto/PostCreateRequest.java

@@ -0,0 +1,18 @@
+package com.example.demo.domain.post.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+
+public record PostCreateRequest(
+        @NotNull(message = "userId는 필수입니다.")
+        Long userId,
+
+        @NotBlank(message = "title은 필수입니다.")
+        String title,
+
+        @NotBlank(message = "content는 필수입니다.")
+        String content,
+
+        String imageUrl
+) {
+}

src/main/java/com/example/demo/domain/post/dto/PostCreateResponse.java

@@ -0,0 +1,7 @@
+package com.example.demo.domain.post.dto;
+
+public record PostCreateResponse(
+        Long postId,
+        String message
+) {
+}

src/main/java/com/example/demo/domain/post/dto/PostDeleteRequest.java

@@ -0,0 +1,9 @@
+package com.example.demo.domain.post.dto;
+
+import jakarta.validation.constraints.NotNull;
+
+public record PostDeleteRequest(
+        @NotNull(message = "userId는 필수입니다.")
+        Long userId
+) {
+}

src/main/java/com/example/demo/domain/post/dto/PostDetailResponse.java

@@ -0,0 +1,15 @@
+package com.example.demo.domain.post.dto;
+
+import java.time.LocalDateTime;
+
+public record PostDetailResponse(
+        Long postId,
+        String title,
+        String content,
+        String imageUrl,
+        Long authorId,
+        String author,
+        LocalDateTime createdAt,
+        LocalDateTime updatedAt
+) {
+}

src/main/java/com/example/demo/domain/post/dto/PostListItemResponse.java

@@ -0,0 +1,13 @@
+package com.example.demo.domain.post.dto;
+
+import java.time.LocalDateTime;
+
+public record PostListItemResponse(
+        Long postId,
+        String title,
+        String content,
+        String thumbnailImageUrl,
+        String author,
+        LocalDateTime createdAt
+) {
+}

src/main/java/com/example/demo/domain/post/dto/PostListResponse.java

@@ -0,0 +1,9 @@
+package com.example.demo.domain.post.dto;
+
+import java.util.List;
+
+public record PostListResponse(
+        List<PostListItemResponse> posts,
+        PageInfoResponse pageInfo
+) {
+}

src/main/java/com/example/demo/domain/post/dto/PostUpdateRequest.java

@@ -0,0 +1,13 @@
+package com.example.demo.domain.post.dto;
+
+import jakarta.validation.constraints.NotNull;
+
+public record PostUpdateRequest(
+        @NotNull(message = "userId는 필수입니다.")
+        Long userId,
+
+        String title,
+        String content,
+        String imageUrl
+) {
+}

src/main/java/com/example/demo/domain/post/entity/Post.java

@@ -40,4 +40,25 @@ public class Post extends BaseEntity {
 
     @OneToMany(mappedBy = "post", cascade = CascadeType.ALL, orphanRemoval = true)
     private List<Comment> comments = new ArrayList<>();
+
+    private Post(User user, String title, String content, String imageUrl) {
+        this.user = user;
+        this.title = title;
+        this.content = content;
+        this.imageUrl = imageUrl;
+    }
+
+    public static Post of(User user, String title, String content, String imageUrl) {
+        return new Post(user, title, content, imageUrl);
+    }
+
+    public void update(String title, String content, String imageUrl) {
+        if (title != null && !title.isBlank()) {
+            this.title = title;
+        }
+        if (content != null && !content.isBlank()) {
+            this.content = content;
+        }
+        this.imageUrl = imageUrl;
+    }
 }

src/main/java/com/example/demo/domain/post/repository/PostRepository.java

@@ -0,0 +1,7 @@
+package com.example.demo.domain.post.repository;
+
+import com.example.demo.domain.post.entity.Post;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PostRepository extends JpaRepository<Post, Long> {
+}

src/main/java/com/example/demo/domain/post/service/PostService.java

@@ -0,0 +1,113 @@
+package com.example.demo.domain.post.service;
+
+import com.example.demo.domain.post.dto.*;
+import com.example.demo.domain.post.entity.Post;
+import com.example.demo.domain.post.repository.PostRepository;
+import com.example.demo.domain.user.entity.User;
+import com.example.demo.domain.user.repository.UserRepository;
+import com.example.demo.global.exception.CustomException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+@Transactional(readOnly = true)
+public class PostService {
+
+    private final PostRepository postRepository;
+    private final UserRepository userRepository;
+
+    public PostListResponse getPosts(int page, int size) {
+        Page<Post> postPage = postRepository.findAll(PageRequest.of(page, size));
+
+        return new PostListResponse(
+                postPage.getContent().stream()
+                        .map(post -> new PostListItemResponse(
+                                post.getId(),
+                                post.getTitle(),
+                                post.getContent(),
+                                post.getImageUrl(),
+                                post.getUser().getName(),
+                                post.getCreatedAt()
+                        ))
+                        .toList(),
+                new PageInfoResponse(
+                        postPage.getNumber(),
+                        postPage.getSize(),
+                        postPage.getTotalElements(),
+                        postPage.getTotalPages(),
+                        postPage.hasNext()
+                )
+        );
+    }
+
+    public PostDetailResponse getPost(Long postId) {
+        Post post = findPost(postId);
+
+        return new PostDetailResponse(
+                post.getId(),
+                post.getTitle(),
+                post.getContent(),
+                post.getImageUrl(),
+                post.getUser().getId(),
+                post.getUser().getName(),
+                post.getCreatedAt(),
+                post.getUpdatedAt()
+        );
+    }
+
+    @Transactional
+    public PostCreateResponse createPost(PostCreateRequest request) {
+        User user = userRepository.findById(request.userId())
+                .orElseThrow(() -> new CustomException(HttpStatus.NOT_FOUND, "USER_NOT_FOUND", "해당 사용자를 찾을 수 없습니다."));
+
+        Post post = Post.of(
+                user,
+                request.title(),
+                request.content(),
+                request.imageUrl()
+        );
+
+        Post savedPost = postRepository.save(post);
+        return new PostCreateResponse(savedPost.getId(), "게시글이 생성되었습니다.");
+    }
+
+    @Transactional
+    public void updatePost(Long postId, PostUpdateRequest request) {
+        Post post = findPost(postId);
+
+        validateOwner(post, request.userId());
+
+        if ((request.title() == null || request.title().isBlank())
+                && (request.content() == null || request.content().isBlank())
+                && request.imageUrl() == null) {
+            throw new CustomException(HttpStatus.BAD_REQUEST, "INVALID_PARAMETER", "수정할 값이 없습니다.");
+        }
+
+        post.update(request.title(), request.content(), request.imageUrl());
+    }
+
+    @Transactional
+    public void deletePost(Long postId, PostDeleteRequest request) {
+        Post post = findPost(postId);
+
+        validateOwner(post, request.userId());
+
+        postRepository.delete(post);
+    }
+
+    private Post findPost(Long postId) {
+        return postRepository.findById(postId)
+                .orElseThrow(() -> new CustomException(HttpStatus.NOT_FOUND, "POST_NOT_FOUND", "해당 게시글을 찾을 수 없습니다."));
+    }
+
+    private void validateOwner(Post post, Long userId) {
+        if (!post.getUser().getId().equals(userId)) {
+            throw new CustomException(HttpStatus.FORBIDDEN, "FORBIDDEN", "권한이 없습니다.");
+        }
+    }
+}

src/main/java/com/example/demo/domain/user/entity/User.java

@@ -14,6 +14,7 @@
 @Getter
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 @Entity
+@Table(name = "user")
 public class User extends BaseEntity {
 
     // 유저 아이디
@@ -25,15 +26,6 @@ public class User extends BaseEntity {
     @Column(nullable = false, length = 10)
     private String name;
 
-    // 성별
-    @Enumerated(EnumType.STRING)
-    @Column(nullable = false)
-    private Gender gender;
-
-    // 나이
-    @Column
-    private Integer age;
-
     @OneToMany(mappedBy = "user")
     private List<Post> posts = new ArrayList<>();
 

src/main/java/com/example/demo/domain/user/repository/UserRepository.java

@@ -0,0 +1,7 @@
+package com.example.demo.domain.user.repository;
+
+import com.example.demo.domain.user.entity.User;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface UserRepository extends JpaRepository<User, Long> {
+}