refactor: SliceResponse로 대체

Author: nayonsoso

src/main/java/com/example/solidconnection/common/dto/SliceResponse.java

@@ -0,0 +1,21 @@
+package com.example.solidconnection.common.dto;
+
+import org.springframework.data.domain.Slice;
+
+import java.util.List;
+
+public record SliceResponse<T>(
+        List<T> content,
+        int nextPageNumber
+) {
+
+    private static final int NO_NEXT_PAGE = -1;
+    private static final int BASE_NUMBER = 1; // 1-based
+
+    public static <T, R> SliceResponse<R> of(Slice<T> slice, List<R> content) {
+        int nextPageNumber = slice.hasNext()
+                ? slice.getNumber() + BASE_NUMBER + 1
+                : NO_NEXT_PAGE;
+        return new SliceResponse<>(content, nextPageNumber);
+    }
+}

src/main/java/com/example/solidconnection/mentor/controller/MentorController.java

@@ -1,8 +1,9 @@
 package com.example.solidconnection.mentor.controller;
 
+import com.example.solidconnection.common.dto.SliceResponse;
 import com.example.solidconnection.common.resolver.AuthorizedUser;
 import com.example.solidconnection.mentor.dto.MentorDetailResponse;
-import com.example.solidconnection.mentor.dto.MentorPreviewsResponse;
+import com.example.solidconnection.mentor.dto.MentorPreviewResponse;
 import com.example.solidconnection.mentor.service.MentorQueryService;
 import com.example.solidconnection.siteuser.domain.SiteUser;
 import lombok.RequiredArgsConstructor;
@@ -34,12 +35,12 @@ public ResponseEntity<MentorDetailResponse> getMentorDetails(
     }
 
     @GetMapping
-    public ResponseEntity<MentorPreviewsResponse> getMentorPreviews(
+    public ResponseEntity<SliceResponse<MentorPreviewResponse>> getMentorPreviews(
             @AuthorizedUser SiteUser siteUser,
             @RequestParam("region") String region,
             @PageableDefault(size = 3, sort = "menteeCount", direction = DESC) Pageable pageable
     ) {
-        MentorPreviewsResponse response = mentorQueryService.getMentorPreviews(region, siteUser, pageable);
+        SliceResponse<MentorPreviewResponse> response = mentorQueryService.getMentorPreviews(region, siteUser, pageable);
         return ResponseEntity.ok(response);
     }
 }

src/main/java/com/example/solidconnection/mentor/dto/MentorPreviewsResponse.java

@@ -1,10 +1,10 @@
 package com.example.solidconnection.mentor.service;
 
+import com.example.solidconnection.common.dto.SliceResponse;
 import com.example.solidconnection.common.exception.CustomException;
 import com.example.solidconnection.mentor.domain.Mentor;
 import com.example.solidconnection.mentor.dto.MentorDetailResponse;
 import com.example.solidconnection.mentor.dto.MentorPreviewResponse;
-import com.example.solidconnection.mentor.dto.MentorPreviewsResponse;
 import com.example.solidconnection.mentor.repository.MentorBatchQueryRepository;
 import com.example.solidconnection.mentor.repository.MentorRepository;
 import com.example.solidconnection.mentor.repository.MentoringRepository;
@@ -45,14 +45,14 @@ public MentorDetailResponse getMentorDetails(long mentorId, SiteUser currentUser
     }
 
     @Transactional(readOnly = true)
-    public MentorPreviewsResponse getMentorPreviews(String region, SiteUser siteUser, Pageable pageable) { // todo: 멘토의 '인증' 작업 후 region 필터링 추가
+    public SliceResponse<MentorPreviewResponse> getMentorPreviews(String region, SiteUser siteUser, Pageable pageable) { // todo: 멘토의 '인증' 작업 후 region 필터링 추가
         Slice<Mentor> mentorPage = mentorRepository.findBy(pageable);
         List<Mentor> mentors = mentorPage.toList();
 
         List<MentorPreviewResponse> content = getContent(mentors, siteUser);
         int pageNumber = getPageNumber(mentorPage);
 
-        return new MentorPreviewsResponse(content, pageNumber);
+        return new SliceResponse<>(content, pageNumber);
     }
 
     private List<MentorPreviewResponse> getContent(List<Mentor> mentors, SiteUser siteUser) {

src/main/java/com/example/solidconnection/mentor/service/MentorQueryService.java

@@ -1,13 +1,13 @@
 package com.example.solidconnection.mentor.service;
 
+import com.example.solidconnection.common.dto.SliceResponse;
 import com.example.solidconnection.common.exception.CustomException;
 import com.example.solidconnection.common.exception.ErrorCode;
 import com.example.solidconnection.mentor.domain.Channel;
 import com.example.solidconnection.mentor.domain.Mentor;
 import com.example.solidconnection.mentor.dto.ChannelResponse;
 import com.example.solidconnection.mentor.dto.MentorDetailResponse;
 import com.example.solidconnection.mentor.dto.MentorPreviewResponse;
-import com.example.solidconnection.mentor.dto.MentorPreviewsResponse;
 import com.example.solidconnection.mentor.fixture.ChannelFixture;
 import com.example.solidconnection.mentor.fixture.MentorFixture;
 import com.example.solidconnection.mentor.fixture.MentoringFixture;
@@ -136,7 +136,7 @@ void setUp() {
             Channel channel2 = channelFixture.채널(2, mentor2);
 
             // when
-            MentorPreviewsResponse response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 10));
+            SliceResponse<MentorPreviewResponse> response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 10));
 
             // then
             Map<Long, MentorPreviewResponse> mentorPreviewMap = response.content().stream()
@@ -160,7 +160,7 @@ void setUp() {
             mentoringFixture.대기중_멘토링(mentor1.getId(), currentUser.getId());
 
             // when
-            MentorPreviewsResponse response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 10));
+            SliceResponse<MentorPreviewResponse> response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 10));
 
             // then
             Map<Long, MentorPreviewResponse> mentorPreviewMap = response.content().stream()
@@ -174,7 +174,7 @@ void setUp() {
         @Test
         void 다음_페이지_번호를_응답한다() {
             // given
-            MentorPreviewsResponse response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 1));
+            SliceResponse<MentorPreviewResponse> response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 1));
 
             // then
             assertThat(response.nextPageNumber()).isEqualTo(2);
@@ -183,7 +183,7 @@ void setUp() {
         @Test
         void 다음_페이지가_없으면_페이지_없음을_의미하는_값을_응답한다() {
             // given
-            MentorPreviewsResponse response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 10));
+            SliceResponse<MentorPreviewResponse> response = mentorQueryService.getMentorPreviews(region, currentUser, PageRequest.of(0, 10));
 
             // then
             assertThat(response.nextPageNumber()).isEqualTo(NO_NEXT_PAGE_NUMBER);