[3주차] 이예서/[feat] 게시글 API 구현

leeyeseo/HELP.md

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+# Getting Started
+
+### Reference Documentation
+For further reference, please consider the following sections:
+
+* [Official Gradle documentation](https://docs.gradle.org)
+* [Spring Boot Gradle Plugin Reference Guide](https://docs.spring.io/spring-boot/3.5.12/gradle-plugin)
+* [Create an OCI image](https://docs.spring.io/spring-boot/3.5.12/gradle-plugin/packaging-oci-image.html)
+* [Spring Web](https://docs.spring.io/spring-boot/3.5.12/reference/web/servlet.html)
+* [Spring Data JPA](https://docs.spring.io/spring-boot/3.5.12/reference/data/sql.html#data.sql.jpa-and-spring-data)
+
+### Guides
+The following guides illustrate how to use some features concretely:
+
+* [Building a RESTful Web Service](https://spring.io/guides/gs/rest-service/)
+* [Serving Web Content with Spring MVC](https://spring.io/guides/gs/serving-web-content/)
+* [Building REST services with Spring](https://spring.io/guides/tutorials/rest/)
+* [Accessing Data with JPA](https://spring.io/guides/gs/accessing-data-jpa/)
+* [Accessing data with MySQL](https://spring.io/guides/gs/accessing-data-mysql/)
+
+### Additional Links
+These additional references should also help you:
+
+* [Gradle Build Scans – insights for your project's build](https://scans.gradle.com#gradle)
+

leeyeseo/build.gradle

@@ -26,6 +26,7 @@ repositories {
 dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
 	implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'org.springframework.boot:spring-boot-starter-validation'
 	compileOnly 'org.projectlombok:lombok'
 	runtimeOnly 'com.mysql:mysql-connector-j'
 	annotationProcessor 'org.projectlombok:lombok'

leeyeseo/src/main/java/com/example/blog/domain/post/controller/PostController.java

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+package com.example.blog.domain.post.controller;
+
+import com.example.blog.domain.post.service.PostService;
+import com.example.blog.dto.post.PostCreateRequest;
+import com.example.blog.dto.post.PostDetailResponse;
+import com.example.blog.dto.post.PostSummaryResponse;
+import com.example.blog.dto.post.PostUpdateRequest;
+import com.example.blog.global.response.ApiResponse;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/posts")
+@RequiredArgsConstructor
+public class PostController {
+
+    private final PostService postService;
+
+    // GET /posts - 게시글 목록 조회
+    @GetMapping
+    public ApiResponse<List<PostSummaryResponse>> getPosts() {
+        return ApiResponse.onSuccess(postService.getPosts());
+    }
+
+    // GET /posts/{postId} - 게시글 상세 조회
+    @GetMapping("/{postId}")
+    public ApiResponse<PostDetailResponse> getPost(@PathVariable Long postId) {
+        return ApiResponse.onSuccess(postService.getPost(postId));
+    }
+
+    // POST /posts - 게시글 작성
+    @PostMapping
+    public ApiResponse<PostDetailResponse> createPost(
+            @Valid @RequestBody PostCreateRequest request) {
+        return ApiResponse.onSuccess(postService.createPost(request));
+    }
+
+    // PATCH /posts/{postId} - 게시글 수정
+    @PatchMapping("/{postId}")
+    public ApiResponse<PostDetailResponse> updatePost(
+            @PathVariable Long postId,
+            @Valid @RequestBody PostUpdateRequest request) {
+        return ApiResponse.onSuccess(postService.updatePost(postId, request));
+    }
+
+    // DELETE /posts/{postId} - 게시글 삭제
+    @DeleteMapping("/{postId}")
+    public ApiResponse<Void> deletePost(
+            @PathVariable Long postId,
+            @RequestParam Long userId) {
+        postService.deletePost(postId, userId);
+        return ApiResponse.onSuccess();
+    }
+}

leeyeseo/src/main/java/com/example/blog/domain/post/converter/PostConverter.java

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+package com.example.blog.domain.post.converter;
+
+import com.example.blog.domain.post.entity.Post;
+import com.example.blog.domain.user.entity.User;
+import com.example.blog.dto.post.PostCreateRequest;
+import com.example.blog.dto.post.PostDetailResponse;
+import com.example.blog.dto.post.PostSummaryResponse;
+
+public class PostConverter {
+
+    // PostCreateRequest + User → Post Entity
+    public static Post toEntity(PostCreateRequest request, User user) {
+        return Post.builder()
+                .user(user)
+                .title(request.getTitle())
+                .content(request.getContent())
+                .imageUrl(request.getImageUrl())
+                .build();
+    }
+
+    // Post Entity → PostDetailResponse
+    public static PostDetailResponse toDetailResponse(Post post) {
+        return PostDetailResponse.builder()
+                .id(post.getId())
+                .title(post.getTitle())
+                .content(post.getContent())
+                .imageUrl(post.getImageUrl())
+                .authorNickname(post.getUser().getNickname())
+                .createdAt(post.getCreatedAt())
+                .updatedAt(post.getUpdatedAt())
+                .build();
+    }
+
+    // Post Entity → PostSummaryResponse (목록용)
+    public static PostSummaryResponse toSummaryResponse(Post post) {
+        return PostSummaryResponse.builder()
+                .id(post.getId())
+                .title(post.getTitle())
+                .authorNickname(post.getUser().getNickname())
+                .createdAt(post.getCreatedAt())
+                .build();
+    }
+}

leeyeseo/src/main/java/com/example/blog/domain/post/repository/PostRepository.java

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+package com.example.blog.domain.post.repository;
+
+import com.example.blog.domain.post.entity.Post;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface PostRepository extends JpaRepository<Post, Long> {
+
+    // soft delete: deletedAt이 null인 것만 조회
+    List<Post> findAllByDeletedAtIsNull();
+
+    Optional<Post> findByIdAndDeletedAtIsNull(Long id);
+}

leeyeseo/src/main/java/com/example/blog/domain/post/service/PostService.java

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+package com.example.blog.domain.post.service;
+
+import com.example.blog.domain.post.converter.PostConverter;
+import com.example.blog.domain.post.entity.Post;
+import com.example.blog.domain.post.repository.PostRepository;
+import com.example.blog.domain.user.entity.User;
+import com.example.blog.domain.user.repository.UserRepository;
+import com.example.blog.dto.post.PostCreateRequest;
+import com.example.blog.dto.post.PostDetailResponse;
+import com.example.blog.dto.post.PostSummaryResponse;
+import com.example.blog.dto.post.PostUpdateRequest;
+import com.example.blog.exception.PostForbiddenException;
+import com.example.blog.exception.PostNotFoundException;
+import com.example.blog.exception.UserNotFoundException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Service
+@RequiredArgsConstructor
+public class PostService {
+
+    private final PostRepository postRepository;
+    private final UserRepository userRepository;
+
+    // 게시글 목록 조회
+    @Transactional(readOnly = true)
+    public List<PostSummaryResponse> getPosts() {
+        return postRepository.findAllByDeletedAtIsNull()
+                .stream()
+                .map(PostConverter::toSummaryResponse)
+                .collect(Collectors.toList());
+    }
+
+    // 게시글 상세 조회
+    @Transactional(readOnly = true)
+    public PostDetailResponse getPost(Long postId) {
+        Post post = postRepository.findByIdAndDeletedAtIsNull(postId)
+                .orElseThrow(() -> new PostNotFoundException(postId));
+        return PostConverter.toDetailResponse(post);
+    }
+
+    // 게시글 작성
+    @Transactional
+    public PostDetailResponse createPost(PostCreateRequest request) {
+        User user = userRepository.findById(request.getUserId())
+                .orElseThrow(() -> new UserNotFoundException(request.getUserId()));
+        Post post = PostConverter.toEntity(request, user);
+        postRepository.save(post);
+        return PostConverter.toDetailResponse(post);
+    }
+
+    // 게시글 수정
+    @Transactional
+    public PostDetailResponse updatePost(Long postId, PostUpdateRequest request) {
+        Post post = postRepository.findByIdAndDeletedAtIsNull(postId)
+                .orElseThrow(() -> new PostNotFoundException(postId));
+
+        // 작성자 권한 확인
+        if (!post.getUser().getId().equals(request.getUserId())) {
+            throw new PostForbiddenException();
+        }
+
+        post.update(request.getTitle(), request.getContent(), request.getImageUrl());
+        return PostConverter.toDetailResponse(post);
+    }
+
+    // 게시글 삭제 (soft delete)
+    @Transactional
+    public void deletePost(Long postId, Long userId) {
+        Post post = postRepository.findByIdAndDeletedAtIsNull(postId)
+                .orElseThrow(() -> new PostNotFoundException(postId));
+
+        // 작성자 권한 확인
+        if (!post.getUser().getId().equals(userId)) {
+            throw new PostForbiddenException();
+        }
+
+        post.delete(); // BaseEntity의 soft delete
+    }
+}

leeyeseo/src/main/java/com/example/blog/domain/user/repository/UserRepository.java

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+package com.example.blog.domain.user.repository;
+
+import com.example.blog.domain.user.entity.User;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface UserRepository extends JpaRepository<User, Long> {
+}

leeyeseo/src/main/java/com/example/blog/dto/post/PostCreateRequest.java

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+package com.example.blog.dto.post;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class PostCreateRequest {
+
+    @NotNull(message = "사용자 ID는 필수입니다.")
+    private Long userId;
+
+    @NotBlank(message = "제목은 필수입니다.")
+    @Size(max = 255, message = "제목은 최대 255자까지 입력 가능합니다.")
+    private String title;
+
+    @NotBlank(message = "본문은 필수입니다.")
+    private String content;
+
+    private String imageUrl;
+}

leeyeseo/src/main/java/com/example/blog/dto/post/PostDetailResponse.java

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+package com.example.blog.dto.post;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Getter
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class PostDetailResponse {
+
+    private Long id;
+    private String title;
+    private String content;
+    private String imageUrl;
+    private String authorNickname;
+    private LocalDateTime createdAt;
+    private LocalDateTime updatedAt;
+}

leeyeseo/src/main/java/com/example/blog/dto/post/PostSummaryResponse.java

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+package com.example.blog.dto.post;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDateTime;
+
+@Getter
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class PostSummaryResponse {
+
+    private Long id;
+    private String title;
+    private String authorNickname;
+    private LocalDateTime createdAt;
+}

leeyeseo/src/main/java/com/example/blog/dto/post/PostUpdateRequest.java

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+package com.example.blog.dto.post;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class PostUpdateRequest {
+
+    @NotNull(message = "사용자 ID는 필수입니다.")
+    private Long userId;
+
+    @NotBlank(message = "제목은 필수입니다.")
+    @Size(max = 255, message = "제목은 최대 255자까지 입력 가능합니다.")
+    private String title;
+
+    @NotBlank(message = "본문은 필수입니다.")
+    private String content;
+
+    private String imageUrl;
+}

leeyeseo/src/main/java/com/example/blog/exception/ErrorCode.java

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+package com.example.blog.exception;
+
+import org.springframework.http.HttpStatus;
+
+public enum ErrorCode {
+
+    // 400
+    BAD_REQUEST(HttpStatus.BAD_REQUEST, "400_000", "잘못된 요청입니다."),
+    MISSING_REQUIRED_VALUE(HttpStatus.BAD_REQUEST, "400_001", "필수 입력값이 누락되었습니다."),
+    TITLE_TOO_LONG(HttpStatus.BAD_REQUEST, "400_002", "제목은 최대 255자까지 입력 가능합니다."),
+    INVALID_TYPE_VALUE(HttpStatus.BAD_REQUEST, "400_004", "데이터 타입이 올바르지 않습니다."),
+
+    // 403
+    FORBIDDEN(HttpStatus.FORBIDDEN, "403_000", "접근 권한이 없습니다."),
+    NOT_POST_OWNER(HttpStatus.FORBIDDEN, "403_001", "해당 게시글의 작성자가 아닙니다."),
+
+    // 404
+    NOT_FOUND_END_POINT(HttpStatus.NOT_FOUND, "404_000", "존재하지 않는 API 경로입니다."),
+    POST_NOT_FOUND(HttpStatus.NOT_FOUND, "404_001", "요청하신 게시글을 찾을 수 없습니다."),
+    USER_NOT_FOUND(HttpStatus.NOT_FOUND, "404_002", "사용자를 찾을 수 없습니다."),
+
+    // 500
+    INTERNAL_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "500_000", "서버 내부 오류가 발생했습니다.");
+
+    private final HttpStatus status;
+    private final String code;
+    private final String message;
+
+    ErrorCode(HttpStatus status, String code, String message) {
+        this.status = status;
+        this.code = code;
+        this.message = message;
+    }
+
+    public HttpStatus getStatus() {
+        return status;
+    }
+
+    public String getCode() {
+        return code;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+}