[FEAT]: 게시글 CRUD 기능 구현

back/src/main/java/com/back/domain/post/controller/PostController.java

@@ -1,9 +1,19 @@
 package com.back.domain.post.controller;
 
+import com.back.domain.post.dto.PostRequest;
+import com.back.domain.post.dto.PostResponse;
 import com.back.domain.post.service.PostService;
+import com.back.global.common.ApiResponse;
+import com.back.global.common.PageResponse;
+import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
 
 /**
  * 게시글 관련 API 요청을 처리하는 컨트롤러.
@@ -15,4 +25,40 @@ public class PostController {
 
     private final PostService postService;
 
+    // 게시글 생성
+    @PostMapping
+    public ApiResponse<PostResponse> createPost(
+            @RequestBody @Valid PostRequest request) {
+        Long userId = 1L; // fixme 임시 사용자 ID
+        PostResponse response = postService.createPost(userId, request);
+        return ApiResponse.success(response, "성공적으로 생성되었습니다.", HttpStatus.OK);
+    }
+
+    // 게시글 목록 조회
+    @GetMapping
+    public ApiResponse<PageResponse<PostResponse>> getPosts(Pageable pageable) {
+        Page<PostResponse> responses = postService.getPosts(pageable);
+        return ApiResponse.success(PageResponse.of(responses), "성공적으로 조회되었습니다.", HttpStatus.OK);
+    }
+
+    // 게시글 단건 조회
+    @GetMapping("/{postId}")
+    public ApiResponse<PostResponse> getPost(@PathVariable Long postId) {
+        return ApiResponse.success(postService.getPost(postId), "성공적으로 조회되었습니다.", HttpStatus.OK);
+    }
+
+    @PutMapping("/{postId}")
+    public ApiResponse<PostResponse> updatePost(
+            @PathVariable Long postId,
+            @RequestBody @Valid PostRequest request) {
+        Long userId = 1L; // fixme 임시 사용자 ID
+        return ApiResponse.success(postService.updatePost(userId, postId, request), "성공적으로 수정되었습니다.", HttpStatus.OK);
+    }
+
+    @DeleteMapping("/{postId}")
+    public ApiResponse<Void> deletePost(@PathVariable Long postId) {
+        Long userId = 1L; // fixme 임시 사용자 ID
+        postService.deletePost(userId, postId);
+        return ApiResponse.success(null, "성공적으로 삭제되었습니다.", HttpStatus.OK);
+    }
 }

back/src/main/java/com/back/domain/post/dto/PostRequest.java

@@ -0,0 +1,18 @@
+package com.back.domain.post.dto;
+
+import com.back.domain.post.enums.PostCategory;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+
+public record PostRequest(
+        @NotBlank(message = "제목은 필수입니다")
+        @Size(max = 200, message = "제목은 200자를 초과할 수 없습니다")
+        String title,
+
+        @NotBlank(message = "내용은 필수입니다")
+        String content,
+
+        @NotNull(message = "카테고리는 필수입니다")
+        PostCategory category
+) { }

back/src/main/java/com/back/domain/post/dto/PostResponse.java

@@ -0,0 +1,25 @@
+package com.back.domain.post.dto;
+
+import com.back.domain.post.enums.PostCategory;
+
+import java.time.LocalDateTime;
+
+/**
+ * @param id
+ * @param title
+ * @param content
+ * @param category
+ * @param hide
+ * @param likeCount
+ * @param createdDate
+ * fixme @param createdBy 추가 예정
+ */
+public record PostResponse(
+        Long id,
+        String title,
+        String content,
+        PostCategory category,
+        boolean hide,
+        int likeCount,
+        LocalDateTime createdDate
+) { }

back/src/main/java/com/back/domain/post/entity/Post.java

@@ -1,14 +1,14 @@
 package com.back.domain.post.entity;
 
+import com.back.domain.post.enums.PostCategory;
 import com.back.domain.user.entity.User;
 import com.back.global.baseentity.BaseEntity;
+import com.back.global.exception.ApiException;
+import com.back.global.exception.ErrorCode;
 import jakarta.persistence.*;
-import lombok.AllArgsConstructor;
-import lombok.Builder;
-import lombok.Getter;
-import lombok.NoArgsConstructor;
-import lombok.Setter;
+import lombok.*;
 import org.hibernate.annotations.ColumnDefault;
+import org.hibernate.service.spi.ServiceException;
 import org.springframework.data.annotation.LastModifiedDate;
 
 import java.time.LocalDateTime;
@@ -19,9 +19,8 @@
  */
 @Entity
 @Getter
-@Setter
-@NoArgsConstructor
-@AllArgsConstructor
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor(access = AccessLevel.PROTECTED)
 @Builder
 public class Post extends BaseEntity {
 
@@ -32,13 +31,16 @@ public class Post extends BaseEntity {
     @Column(length = 200)
     private String title;
 
-    @Column(length = 200)
-    private String category;
+    @Column(length = 20)
+    @Enumerated(EnumType.STRING)
+    private PostCategory category;
 
     @Column(columnDefinition = "TEXT")
     private String content;
 
-    @Column(columnDefinition = "jsonb")
+    /**
+     * JSON 데이터를 단순 문자열로 저장 (예: {"option1": 10, "option2": 5})
+     */
     private String voteContent;
 
     @Column(nullable = false)
@@ -49,4 +51,19 @@ public class Post extends BaseEntity {
 
     @LastModifiedDate
     private LocalDateTime updatedAt;
+
+    public void assignUser(User user) {
+        this.user = user;
+    }
+
+    public void updatePost(String title, String content, PostCategory category) {
+        this.title = title;
+        this.content = content;
+        this.category = category;
+    }
+
+    public void checkUser(User targetUser) {
+        if (!user.equals(targetUser))
+            throw new ApiException(ErrorCode.UNAUTHORIZED_USER);
+    }
 }

back/src/main/java/com/back/domain/post/enums/PostCategory.java

@@ -0,0 +1,7 @@
+package com.back.domain.post.enums;
+
+public enum PostCategory {
+    CHAT,       // 잡담
+    SCENARIO,   // 시나리오 첨부
+    POLL        // 투표
+}

back/src/main/java/com/back/domain/post/mapper/PostMapper.java

@@ -0,0 +1,41 @@
+package com.back.domain.post.mapper;
+
+import com.back.domain.post.dto.PostRequest;
+import com.back.domain.post.dto.PostResponse;
+import com.back.domain.post.entity.Post;
+
+import java.util.List;
+
+/**
+ * PostMapper
+ * 엔티티와 PostRequest, PostResponse 간의 변환을 담당하는 매퍼 클래스
+ */
+public abstract class PostMapper {
+    public static Post toEntity(PostRequest request) {
+        return Post.builder()
+                .title(request.title())
+                .content(request.content())
+                .category(request.category())
+                .hide(false)
+                .likeCount(0)
+                .build();
+    }
+
+    public static PostResponse toResponse(Post post) {
+        return new PostResponse(
+                post.getId(),
+                post.getTitle(),
+                post.getContent(),
+                post.getCategory(),
+                post.isHide(),
+                post.getLikeCount(),
+                post.getCreatedDate()
+        );
+    }
+
+    public static List<PostResponse> toResponseList(List<Post> posts) {
+        return posts.stream()
+                .map(PostMapper::toResponse)
+                .toList();
+    }
+}

back/src/main/java/com/back/domain/post/service/PostService.java

@@ -1,16 +1,82 @@
 package com.back.domain.post.service;
 
+import com.back.domain.post.dto.PostRequest;
+import com.back.domain.post.dto.PostResponse;
+import com.back.domain.post.entity.Post;
+import com.back.domain.post.mapper.PostMapper;
 import com.back.domain.post.repository.PostRepository;
+import com.back.domain.user.entity.User;
+import com.back.domain.user.repository.UserRepository;
+import com.back.global.exception.ApiException;
+import com.back.global.exception.ErrorCode;
 import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.Optional;
 
 /**
  * 게시글 관련 비즈니스 로직을 처리하는 서비스.
  */
 @Service
 @RequiredArgsConstructor
+@Transactional(readOnly = true)
 public class PostService {
 
+    private final UserRepository userRepository;
     private final PostRepository postRepository;
 
+    @Transactional
+    public PostResponse createPost(Long userId, PostRequest request) {
+        User user = userRepository.findById(userId)
+                .orElseThrow(() -> new ApiException(ErrorCode.USER_NOT_FOUND));
+
+        Post post = PostMapper.toEntity(request);
+        post.assignUser(user);
+        Post savedPost = postRepository.save(post);
+
+        return PostMapper.toResponse(savedPost);
+    }
+
+    public PostResponse getPost(Long postId) {
+        return postRepository.findById(postId)
+                .filter(post -> !post.isHide())
+                .map(PostMapper::toResponse)
+                .orElseThrow(() -> new ApiException(ErrorCode.POST_NOT_FOUND));
+    }
+
+    public Page<PostResponse> getPosts(Pageable pageable) {
+        return postRepository.findAll(pageable)
+                .map(PostMapper::toResponse);
+    }
+
+    @Transactional
+    public PostResponse updatePost(Long userId, Long postId, PostRequest request) {
+        Post post = validatePostOwnership(userId, postId);
+
+        post.updatePost(request.title(), request.content(), request.category());
+
+        return PostMapper.toResponse(post);
+    }
+
+    @Transactional
+    public void deletePost(Long userId, Long postId) {
+        Post post = validatePostOwnership(userId, postId);
+        postRepository.delete(post);
+    }
+
+    private Post validatePostOwnership(Long userId, Long postId) {
+        Post post = postRepository.findById(postId)
+                .orElseThrow(() -> new ApiException(ErrorCode.POST_NOT_FOUND));
+
+        User requestUser = userRepository.findById(userId)
+                .orElseThrow(() -> new ApiException(ErrorCode.USER_NOT_FOUND));
+
+        post.checkUser(requestUser);
+
+        return post;
+    }
 }

back/src/main/java/com/back/global/common/ApiResponse.java

@@ -0,0 +1,37 @@
+package com.back.global.common;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+/**
+ * 공통 응답 형태
+ * {
+ *   "data": { ... },
+ *   "message": "성공적으로 조회되었습니다.",
+ *   "status": 200
+ * }
+ */
+@Getter
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public class ApiResponse<T> {
+
+    private final T data;
+    private final String message;
+    private final int status;
+
+    private ApiResponse(T data, String message, int status) {
+        this.data = data;
+        this.message = message;
+        this.status = status;
+    }
+
+    public static <T> ApiResponse<T> success(T data, String message) {
+        return new ApiResponse<>(data, message, HttpStatus.OK.value());
+    }
+
+    public static <T> ApiResponse<T> success(T data, String message, HttpStatus status) {
+        return new ApiResponse<>(data, message, status.value());
+    }
+}

back/src/main/java/com/back/global/common/PageResponse.java

@@ -0,0 +1,29 @@
+package com.back.global.common;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.springframework.data.domain.Page;
+
+import java.util.List;
+
+@Getter
+@AllArgsConstructor
+public class PageResponse<T> {
+    private List<T> items;
+    private int page;
+    private int size;
+    private long totalElements;
+    private int totalPages;
+    private boolean last;
+
+    public static <T> PageResponse<T> of(Page<T> page) {
+        return new PageResponse<>(
+                page.getContent(),
+                page.getNumber() + 1, // 응답도 1페이지 시작으로 반환, Page 객체는 0페이지부터 시작
+                page.getSize(),
+                page.getTotalElements(),
+                page.getTotalPages(),
+                page.isLast()
+        );
+    }
+}