인기게시글 랭킹 목록 조회 기능

backend/src/main/java/com/votogether/domain/post/controller/PostController.java

@@ -4,6 +4,7 @@
 import com.votogether.domain.post.dto.request.post.PostCreateRequest;
 import com.votogether.domain.post.dto.request.post.PostUpdateRequest;
 import com.votogether.domain.post.dto.response.post.PostDetailResponse;
+import com.votogether.domain.post.dto.response.post.PostRankingResponse;
 import com.votogether.domain.post.dto.response.post.PostResponse;
 import com.votogether.domain.post.dto.response.vote.VoteOptionStatisticsResponse;
 import com.votogether.domain.post.entity.vo.PostClosingType;
@@ -175,6 +176,12 @@ public ResponseEntity<Void> save(
  return ResponseEntity.created(URI.create("/posts/" + postId)).build();
  }
 
+ @GetMapping("ranking/popular/guest")
+ public ResponseEntity<List<PostRankingResponse>> getRanking() {
+ final List<PostRankingResponse> responses = postService.getRanking();
+ return ResponseEntity.ok(responses);
+ }
+
  @PutMapping(value = "/{postId}", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
  public ResponseEntity<Void> update(
  @PathVariable final Long postId,

backend/src/main/java/com/votogether/domain/post/controller/PostControllerDocs.java

@@ -4,6 +4,7 @@
 import com.votogether.domain.post.dto.request.post.PostCreateRequest;
 import com.votogether.domain.post.dto.request.post.PostUpdateRequest;
 import com.votogether.domain.post.dto.response.post.PostDetailResponse;
+import com.votogether.domain.post.dto.response.post.PostRankingResponse;
 import com.votogether.domain.post.dto.response.post.PostResponse;
 import com.votogether.domain.post.dto.response.vote.VoteOptionStatisticsResponse;
 import com.votogether.domain.post.entity.vo.PostClosingType;
@@ -186,6 +187,10 @@ ResponseEntity<List<PostResponse>> getPostsByMe(
  final Member member
  );
 
+ @Operation(summary = "인기 게시글 랭킹 조회", description = "인기 게시글 랭킹을 조회한다.")
+ @ApiResponse(responseCode = "200", description = "인기 게시글 랭킹 조회 성공")
+ ResponseEntity<List<PostRankingResponse>> getRanking();
+
  @Operation(summary = "게시글 작성", description = "게시글을 작성한다.")
  @ApiResponses({
  @ApiResponse(responseCode = "201", description = "게시글 작성 성공"),

backend/src/main/java/com/votogether/domain/post/dto/response/post/PostRankingResponse.java

@@ -0,0 +1,13 @@
+package com.votogether.domain.post.dto.response.post;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@Schema(description = "게시글 랭킹 정보 응답")
+public record PostRankingResponse(
+ @Schema(description = "게시글 랭킹", example = "1")
+ int ranking,
+
+ @Schema(description = "게시글 정보")
+ PostSummaryResponse postSummaryResponse
+) {
+}

backend/src/main/java/com/votogether/domain/post/dto/response/post/PostSummaryResponse.java

@@ -0,0 +1,30 @@
+package com.votogether.domain.post.dto.response.post;
+
+import com.votogether.domain.post.entity.Post;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@Schema(description = "게시글 간략 정보 응답")
+public record PostSummaryResponse(
+ @Schema(description = "게시글 ID", example = "1")
+ Long id,
+
+ @Schema(description = "작성자", example = "익명의손님1")
+ String writer,
+
+ @Schema(description = "게시글 제목", example = "제목")
+ String title,
+
+ @Schema(description = "투표 수", example = "123")
+ long voteCount
+) {
+
+ public static PostSummaryResponse from(final Post post) {
+ return new PostSummaryResponse(
+ post.getId(),
+ post.getWriter().getNickname(),
+ post.getPostBody().getTitle(),
+ post.getTotalVoteCount()
+ );
+ }
+
+}

backend/src/main/java/com/votogether/domain/post/service/PostService.java

@@ -11,7 +11,9 @@
 import com.votogether.domain.post.dto.request.post.PostOptionUpdateRequest;
 import com.votogether.domain.post.dto.request.post.PostUpdateRequest;
 import com.votogether.domain.post.dto.response.post.PostDetailResponse;
+import com.votogether.domain.post.dto.response.post.PostRankingResponse;
 import com.votogether.domain.post.dto.response.post.PostResponse;
+import com.votogether.domain.post.dto.response.post.PostSummaryResponse;
 import com.votogether.domain.post.dto.response.vote.VoteOptionStatisticsResponse;
 import com.votogether.domain.post.entity.Post;
 import com.votogether.domain.post.entity.PostBody;
@@ -365,5 +367,44 @@ private <T, R> List<R> transformElements(final List<T> elements, final Function<
  .toList();
  }
 
+ @Transactional(readOnly = true)
+ public List<PostRankingResponse> getRanking() {
+ final List<Post> posts = postRepository.findAllByClosingTypeAndSortTypeAndCategoryId(
+ PostClosingType.ALL,
+ PostSortType.HOT,
+ null,
+ PageRequest.of(0, BASIC_PAGING_SIZE)
+ );
+
+ final Map<Post, Integer> rankings = calculateRanking(posts);
+
+ return rankings.entrySet().stream()
+ .map(entry ->
+ new PostRankingResponse(
+ entry.getValue(),
+ PostSummaryResponse.from(entry.getKey())
+ )
+ )
+ .toList();
+ }
+
+ private Map<Post, Integer> calculateRanking(final List<Post> posts) {
+ final Map<Post, Integer> rankings = new LinkedHashMap<>();
+
+ int currentRanking = 1;
+ int previousRanking = -1;
+ long previousVoteCount = -1;
+ for (Post post : posts) {
+ final long currentVoteCount = post.getTotalVoteCount();
+ final int ranking = (currentVoteCount == previousVoteCount) ? previousRanking : currentRanking;
+ rankings.put(post, ranking);
+
+ previousRanking = ranking;
+ previousVoteCount = currentVoteCount;
+ currentRanking++;
+ }
+
+ return rankings;
+ }
 }
 

backend/src/test/java/com/votogether/domain/post/controller/PostControllerTest.java

@@ -23,7 +23,9 @@
 import com.votogether.domain.post.dto.request.post.PostOptionUpdateRequest;
 import com.votogether.domain.post.dto.request.post.PostUpdateRequest;
 import com.votogether.domain.post.dto.response.post.PostDetailResponse;
+import com.votogether.domain.post.dto.response.post.PostRankingResponse;
 import com.votogether.domain.post.dto.response.post.PostResponse;
+import com.votogether.domain.post.dto.response.post.PostSummaryResponse;
 import com.votogether.domain.post.dto.response.post.WriterResponse;
 import com.votogether.domain.post.dto.response.vote.VoteCountForAgeGroupResponse;
 import com.votogether.domain.post.dto.response.vote.VoteDetailResponse;
@@ -57,6 +59,7 @@
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
+import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 import org.springframework.web.context.WebApplicationContext;
 
@@ -658,6 +661,7 @@ void postClosedEarly() throws Exception {
  assertThat(response.statusCode()).isEqualTo(HttpStatus.OK.value());
  }
 
+ @Test
  @DisplayName("회원본인이 작성한 게시글 목록을 조회한다.")
  void getPostsByWriter() throws JsonProcessingException {
  // given
@@ -802,7 +806,7 @@ void searchPostsWithKeywordForGuest() {
  assertThat(result.get(0)).usingRecursiveComparison().isEqualTo(postResponse);
  }
 
-
+ @Test
  @DisplayName("게시글을 삭제한다.")
  void delete() {
  // given
@@ -871,4 +875,29 @@ void update() throws IOException {
  .status(HttpStatus.OK);
  }
 
+ @Test
+ @DisplayName("인기 게시물 랭킹을 불러온다.")
+ void getRanking() {
+ // given
+ Post post = Post.builder()
+ .postBody(PostBody.builder().title("제목").build())
+ .writer(MemberFixtures.MALE_10.get())
+ .build();
+ ReflectionTestUtils.setField(post, "id", 1L);
+
+ PostRankingResponse postRankingResponse = new PostRankingResponse(1, PostSummaryResponse.from(post));
+ given(postService.getRanking()).willReturn(List.of(postRankingResponse));
+
+ // when, then
+ List<PostRankingResponse> result = RestAssuredMockMvc.given().log().all()
+ .when().get("/posts/ranking/popular/guest")
+ .then().log().all()
+ .status(HttpStatus.OK)
+ .extract()
+ .as(new ParameterizedTypeReference<List<PostRankingResponse>>() {
+ }.getType());
+
+ assertThat(result).isEqualTo(List.of(postRankingResponse));
+ }
+
 }