feature: 글 내용 조회 api 추가 (#40)

* feature: 글 내용 조회 api 추가

* fix: spring transactional로 교체

src/main/java/com/goldbalance/dive/domain/article/controller/ArticleController.java

@@ -2,6 +2,7 @@
 
 import com.goldbalance.dive.domain.article.domain.Article;
 import com.goldbalance.dive.domain.article.domain.Quiz;
+import com.goldbalance.dive.domain.article.dto.ArticleDto;
 import com.goldbalance.dive.domain.article.dto.request.ArticleQueryOption;
 import com.goldbalance.dive.domain.article.service.ArticleService;
 import java.util.List;
@@ -26,4 +27,10 @@ public ResponseEntity<List<Quiz>> findQuizzes(@PathVariable Long articleId, @Req
         List<Quiz> response = articleService.findQuizzes(articleId);
         return ResponseEntity.ok(response);
     }
+
+    @GetMapping("/{articleId}")
+    public ResponseEntity<ArticleDto> getArticleContents(@PathVariable Long articleId, @RequestBody String nickname) {
+        ArticleDto response = articleService.getArticleContents(nickname, articleId);
+        return ResponseEntity.ok(response);
+    }
 }

src/main/java/com/goldbalance/dive/domain/article/dto/ArticleDto.java

@@ -0,0 +1,25 @@
+package com.goldbalance.dive.domain.article.dto;
+
+import com.goldbalance.dive.domain.article.domain.ArticleContent;
+import java.util.List;
+
+public record ArticleDto(String nickname, String title, int totalContents, List<Content> contents) {
+
+    public static ArticleDto of(String nickname, List<ArticleContent> contents) {
+        List<Content> contentList = contents.stream()
+                .map(articleContent -> new Content(articleContent.getSubTitle(), articleContent.getContent()))
+                .toList();
+
+        return new ArticleDto(nickname, contents.get(0).getArticle().getTitle(), contents.size(), contentList);
+    }
+
+    static class Content {
+        private String subtitle;
+        private String content;
+
+        public Content(String subtitle, String content) {
+            this.subtitle = subtitle;
+            this.content = content;
+        }
+    }
+}

src/main/java/com/goldbalance/dive/domain/article/repository/ArticleContentRepository.java

@@ -0,0 +1,10 @@
+package com.goldbalance.dive.domain.article.repository;
+
+import com.goldbalance.dive.domain.article.domain.ArticleContent;
+import java.util.List;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ArticleContentRepository extends JpaRepository<ArticleContent, Long> {
+
+    List<ArticleContent> findAllByArticleId(Long articleId);
+}

src/main/java/com/goldbalance/dive/domain/article/service/ArticleService.java

@@ -1,21 +1,27 @@
 package com.goldbalance.dive.domain.article.service;
 
 import com.goldbalance.dive.domain.article.domain.Article;
+import com.goldbalance.dive.domain.article.domain.ArticleContent;
 import com.goldbalance.dive.domain.article.domain.Quiz;
+import com.goldbalance.dive.domain.article.dto.ArticleDto;
 import com.goldbalance.dive.domain.article.dto.request.ArticleQueryOption;
+import com.goldbalance.dive.domain.article.repository.ArticleContentRepository;
 import com.goldbalance.dive.domain.article.repository.article.ArticleRepository;
 import com.goldbalance.dive.domain.article.repository.quiz.QuizRepository;
-import jakarta.transaction.Transactional;
+import com.goldbalance.dive.global.exception.CustomException;
+import com.goldbalance.dive.global.exception.ErrorCode;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
 
 @Service
 @RequiredArgsConstructor
-@Transactional
+@Transactional(readOnly = true)
 public class ArticleService {
 
     private final ArticleRepository articleRepository;
+    private final ArticleContentRepository articleContentRepository;
     private final QuizRepository quizRepository;
 
     public List<Article> findArticles(ArticleQueryOption queryOption) {
@@ -25,4 +31,12 @@ public List<Article> findArticles(ArticleQueryOption queryOption) {
     public List<Quiz> findQuizzes(Long articleId) {
         return quizRepository.searchQuiz(articleId);
     }
+
+    public ArticleDto getArticleContents(String nickname, Long articleId) {
+        List<ArticleContent> articleContents = articleContentRepository.findAllByArticleId(articleId);
+        if (articleContents.isEmpty()) {
+            throw new CustomException(ErrorCode.ARTICLE_NOT_FOUND);
+        }
+        return ArticleDto.of(nickname, articleContents);
+    }
 }

src/main/java/com/goldbalance/dive/global/exception/ErrorCode.java

@@ -11,7 +11,10 @@ public enum ErrorCode {
 
     // Member
     MEMBER_NICKNAME_DUPLICATE(HttpStatus.BAD_REQUEST, "이미 존재하는 닉네임입니다."),
-    MEMBER_NOT_FOUND(HttpStatus.NOT_FOUND, "존재하지 않는 멤버입니다.");
+    MEMBER_NOT_FOUND(HttpStatus.NOT_FOUND, "존재하지 않는 멤버입니다."),
+
+    // Article
+    ARTICLE_NOT_FOUND(HttpStatus.NOT_FOUND, "존재하지 않는 글입니다.");
 
     private final HttpStatus status;
     private final String message;