[BE] issue467: 스터디 목록 조회 커서 기반 페이징

backend/src/main/java/com/woowacourse/moamoa/study/controller/SearchingStudyController.java

@@ -6,8 +6,6 @@
 import com.woowacourse.moamoa.study.service.response.StudyDetailResponse;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
-import org.springframework.data.domain.Pageable;
-import org.springframework.data.web.PageableDefault;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -24,9 +22,12 @@ public class SearchingStudyController {
 
     @GetMapping
     public ResponseEntity<StudiesResponse> getStudies(
-            @PageableDefault(size = 5) final Pageable pageable
+            @RequestParam(required = false) final Long id,
+            @RequestParam(required = false, defaultValue = "") final String createdDate,
+            @RequestParam(required = false, defaultValue = "5") final int size
     ) {
-        final StudiesResponse studiesResponse = searchingStudyService.getStudies("", SearchingTags.emptyTags(), pageable);
+        final StudiesResponse studiesResponse = searchingStudyService.getStudies("", SearchingTags.emptyTags(), id,
+                createdDate, size);
         return ResponseEntity.ok().body(studiesResponse);
     }
 
@@ -36,10 +37,13 @@ public ResponseEntity<StudiesResponse> searchStudies(
             @RequestParam(required = false, name = "generation", defaultValue = "") final List<Long> generations,
             @RequestParam(required = false, name = "area", defaultValue = "") final List<Long> areas,
             @RequestParam(required = false, name = "subject", defaultValue = "") final List<Long> tags,
-            @PageableDefault(size = 5) final Pageable pageable
+            @RequestParam(required = false) final Long id,
+            @RequestParam(required = false, defaultValue = "") final String createdDate,
+            @RequestParam(required = false, defaultValue = "5") final int size
     ) {
         final SearchingTags searchingTags = new SearchingTags(generations, areas, tags);
-        final StudiesResponse studiesResponse = searchingStudyService.getStudies(title.trim(), searchingTags, pageable);
+        final StudiesResponse studiesResponse = searchingStudyService.getStudies(title.trim(), searchingTags, id,
+                createdDate, size);
         return ResponseEntity.ok().body(studiesResponse);
     }
 

backend/src/main/java/com/woowacourse/moamoa/study/query/SearchingTags.java

@@ -32,4 +32,10 @@ public List<Long> getTagIdsBy(CategoryName name) {
     public static SearchingTags emptyTags() {
         return new SearchingTags(List.of(), List.of(), List.of());
     }
+
+    public boolean isEmpty() {
+        return tags.values()
+                .stream()
+                .allMatch(List::isEmpty);
+    }
 }

backend/src/main/java/com/woowacourse/moamoa/study/query/StudySummaryDao.java

@@ -2,6 +2,8 @@
 
 import com.woowacourse.moamoa.study.query.data.StudySummaryData;
 import com.woowacourse.moamoa.tag.domain.CategoryName;
+import java.time.LocalDateTime;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -25,34 +27,30 @@ public class StudySummaryDao {
         final String excerpt = resultSet.getString("excerpt");
         final String thumbnail = resultSet.getString("thumbnail");
         final String status = resultSet.getString("recruitment_status");
+        final LocalDateTime createdDate = resultSet.getObject("created_at", LocalDateTime.class);
 
-        return new StudySummaryData(id, title, excerpt, thumbnail, status);
+        return new StudySummaryData(id, title, excerpt, thumbnail, status, createdDate);
     };
 
     private final NamedParameterJdbcTemplate jdbcTemplate;
 
-    public Slice<StudySummaryData> searchBy(final String title, final SearchingTags searchingTags, final Pageable pageable) {
+    public Slice<StudySummaryData> searchBy(final String title, final SearchingTags searchingTags, final Long id,
+                                            final LocalDateTime createdAt, final int size) {
         final List<StudySummaryData> data = jdbcTemplate
-                .query(sql(searchingTags, title), params(title, searchingTags, pageable), STUDY_ROW_MAPPER);
-        return new SliceImpl<>(getCurrentPageStudies(data, pageable), pageable, hasNext(data, pageable));
+                .query(sql(title, searchingTags, id, createdAt), params(title, searchingTags, id, createdAt, size),
+                        STUDY_ROW_MAPPER);
+        return new SliceImpl<>(getCurrentPageStudies(data, size), Pageable.ofSize(size), hasNext(data, size));
     }
 
-    private String sql(final SearchingTags searchingTags, final String title) {
+    private String sql(final String title, final SearchingTags searchingTags, final Long id,
+                       final LocalDateTime createdAt) {
         return "SELECT study.id, study.title, study.excerpt, study.thumbnail, study.recruitment_status, study.created_at "
-                + "FROM study "
-                + joinTableClause(searchingTags)
-                + joinTitleClause(title)
-                + filtersInQueryClause(searchingTags)
-                + "GROUP BY study.id "
-                + "ORDER BY study.created_at DESC "
-                + "LIMIT :limit OFFSET :offset ";
-    }
-
-    private String joinTitleClause(final String title) {
-        if (title.isBlank()) {
-            return "";
-        }
-        return "WHERE UPPER(study.title) LIKE UPPER(:title) ESCAPE '\' ";
+                        + "FROM study "
+                        + joinTableClause(searchingTags)
+                        + whereCondition(id, createdAt, title, searchingTags)
+                        + "GROUP BY study.id "
+                        + "ORDER BY study.created_at DESC, id DESC "
+                        + "LIMIT :limit ";
     }
 
     private String joinTableClause(final SearchingTags searchingTags) {
@@ -66,6 +64,45 @@ private String joinTableClause(final SearchingTags searchingTags) {
                 .collect(Collectors.joining());
     }
 
+    private String whereCondition(final Long id, final LocalDateTime createdAt, final String title,
+                                  final SearchingTags searchingTags) {
+        if (!hasCondition(id, createdAt, title, searchingTags)) {
+            return "";
+        }
+
+        final String cursorClause = filtersInCursorClause(id, createdAt);
+        final String titleClause = filtersTitleClause(title);
+        final String filtersInQueryClause = filtersInQueryClause(searchingTags);
+        final String combinedClause = combineClause(cursorClause, titleClause);
+
+        if (combinedClause.isBlank()) {
+            return "WHERE " + filtersInQueryClause.replaceFirst("AND ", "");
+        }
+
+        return "WHERE " + combineClause(cursorClause, titleClause) + filtersInQueryClause;
+    }
+
+    private boolean hasCondition(final Long id, final LocalDateTime createdAt,
+                                        final String title, final SearchingTags searchingTags) {
+        return id != null || createdAt != null || !title.isBlank() || !searchingTags.isEmpty();
+    }
+
+
+    private String filtersInCursorClause(final Long id, final LocalDateTime createdAt) {
+        if (id != null && createdAt != null) {
+            return "(study.created_at < :createdAt OR (study.created_at = :createdAt AND id < :id)) ";
+        }
+
+        return "";
+    }
+
+    private String filtersTitleClause(final String title) {
+        if (title.isBlank()) {
+            return "";
+        }
+        return "UPPER(study.title) LIKE UPPER(:title) ESCAPE '\' ";
+    }
+
     private String filtersInQueryClause(final SearchingTags searchingTags) {
         String sql = "AND {}_tag.id IN (:{}) ";
 
@@ -75,27 +112,47 @@ private String filtersInQueryClause(final SearchingTags searchingTags) {
                 .collect(Collectors.joining());
     }
 
-    private Map<String, Object> params(final String title, final SearchingTags searchingTags,
-                                       final Pageable pageable) {
+    private String combineClause(String... clauses) {
+        final List<String> notBlankClauses = Arrays.stream(clauses)
+                .filter(it -> !it.isBlank())
+                .collect(Collectors.toList());
+
+        if (notBlankClauses.isEmpty()) {
+            return "";
+        }
+
+        StringBuilder stringBuilder = new StringBuilder(notBlankClauses.get(0));
+        for (int i = 1; i < notBlankClauses.size(); i++) {
+            stringBuilder.append("AND " + notBlankClauses.get(i));
+        }
+
+        return stringBuilder.toString();
+    }
+
+    private Map<String, Object> params(final String title, final SearchingTags searchingTags, final Long id,
+                                       final LocalDateTime createdAt,
+                                       final int size) {
         final Map<String, Object> tagIds = Stream.of(CategoryName.values())
                 .collect(Collectors.toMap(name -> name.name().toLowerCase(), searchingTags::getTagIdsBy));
 
         Map<String, Object> param = new HashMap<>();
         param.put("title", "%" + title + "%");
-        param.put("limit", pageable.getPageSize() + 1);
-        param.put("offset", pageable.getOffset());
+        param.put("id", id);
+        param.put("createdAt", createdAt);
+        param.put("limit", size + 1);
         param.putAll(tagIds);
         return param;
     }
 
-    private List<StudySummaryData> getCurrentPageStudies(final List<StudySummaryData> studies, final Pageable pageable) {
-        if (hasNext(studies, pageable)) {
+    private List<StudySummaryData> getCurrentPageStudies(final List<StudySummaryData> studies,
+                                                         final int size) {
+        if (hasNext(studies, size)) {
             return studies.subList(0, studies.size() - 1);
         }
         return studies;
     }
 
-    private boolean hasNext(final List<StudySummaryData> studies, final Pageable pageable) {
-        return studies.size() > pageable.getPageSize();
+    private boolean hasNext(final List<StudySummaryData> studies, final int size) {
+        return studies.size() > size;
     }
 }

backend/src/main/java/com/woowacourse/moamoa/study/query/data/StudySummaryData.java

@@ -1,5 +1,6 @@
 package com.woowacourse.moamoa.study.query.data;
 
+import java.time.LocalDateTime;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
@@ -14,4 +15,5 @@ public class StudySummaryData {
     private String excerpt;
     private String thumbnail;
     private String recruitmentStatus;
+    private LocalDateTime createdDate;
 }

backend/src/main/java/com/woowacourse/moamoa/study/service/SearchingStudyService.java

@@ -1,5 +1,7 @@
 package com.woowacourse.moamoa.study.service;
 
+import static java.time.format.DateTimeFormatter.ISO_DATE_TIME;
+
 import com.woowacourse.moamoa.member.query.MemberDao;
 import com.woowacourse.moamoa.member.query.data.ParticipatingMemberData;
 import com.woowacourse.moamoa.study.query.SearchingTags;
@@ -13,10 +15,10 @@
 import com.woowacourse.moamoa.tag.query.TagDao;
 import com.woowacourse.moamoa.tag.query.response.TagData;
 import com.woowacourse.moamoa.tag.query.response.TagSummaryData;
+import java.time.LocalDateTime;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
-import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Slice;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -42,15 +44,18 @@ public SearchingStudyService(
         this.tagDao = tagDao;
     }
 
-    public StudiesResponse getStudies(final String title, final SearchingTags searchingTags, final Pageable pageable) {
-        final Slice<StudySummaryData> studyData = studySummaryDao.searchBy(title.trim(), searchingTags, pageable);
+    public StudiesResponse getStudies(final String title, final SearchingTags searchingTags, final Long id,
+                                      final String createdDate, final int size) {
+        final LocalDateTime lastCreatedDate = getCreatedDate(createdDate);
+        final Slice<StudySummaryData> studyData = studySummaryDao.searchBy(
+                title.trim(), searchingTags, id, lastCreatedDate, size);
 
         final List<Long> studyIds = studyData.getContent().stream()
                 .map(StudySummaryData::getId)
                 .collect(Collectors.toList());
         final Map<Long, List<TagSummaryData>> studyTags = tagDao.findTagsByStudyIds(studyIds);
 
-        return new StudiesResponse(studyData.getContent(), studyTags, studyData.hasNext());
+        return StudiesResponse.of(studyData.getContent(), studyTags, studyData.hasNext());
     }
 
     public StudyDetailResponse getStudyDetails(final Long studyId) {
@@ -61,4 +66,11 @@ public StudyDetailResponse getStudyDetails(final Long studyId) {
         final List<TagData> attachedTags = tagDao.findTagsByStudyId(studyId);
         return new StudyDetailResponse(content, participants, attachedTags);
     }
+
+    private LocalDateTime getCreatedDate(final String createdDate) {
+        if (createdDate.isBlank()) {
+            return null;
+        }
+        return LocalDateTime.parse(createdDate, ISO_DATE_TIME);
+    }
 }

backend/src/main/java/com/woowacourse/moamoa/study/service/response/StudiesResponse.java

@@ -1,38 +1,53 @@
 package com.woowacourse.moamoa.study.service.response;
 
+import static java.time.format.DateTimeFormatter.ISO_DATE_TIME;
+
 import com.woowacourse.moamoa.study.query.data.StudySummaryData;
 import com.woowacourse.moamoa.tag.query.response.TagSummaryData;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
-import lombok.AllArgsConstructor;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 
 @Getter
 @NoArgsConstructor
-@AllArgsConstructor
 public class StudiesResponse {
 
     private List<StudyResponse> studies;
     private boolean hasNext;
+    private Long id;
+    private String createdDate;
 
-    public StudiesResponse(
-            final List<StudySummaryData> studySummaryData,
-            final Map<Long, List<TagSummaryData>> studyTags,
-            final boolean hasNext
-    ) {
-
-        this.studies = getStudyResponses(studySummaryData, studyTags);
+    private StudiesResponse(final List<StudyResponse> studies, final boolean hasNext, final Long id,
+                           final String createdDate) {
+        this.studies = studies;
         this.hasNext = hasNext;
+        this.id = id;
+        this.createdDate = createdDate;
+    }
+
+    public static StudiesResponse of(final List<StudySummaryData> studySummaryData,
+                                     final Map<Long, List<TagSummaryData>> studyTags, final boolean hasNext) {
+        final List<StudyResponse> studies = getStudyResponses(studySummaryData, studyTags);
+        if (studies.isEmpty()) {
+            return new StudiesResponse(studies, hasNext, null, "");
+        }
+
+        final StudySummaryData lastStudy = getLastStudyResponse(studySummaryData);
+        return new StudiesResponse(studies, hasNext, lastStudy.getId(), lastStudy.getCreatedDate().format(ISO_DATE_TIME));
     }
 
-    private List<StudyResponse> getStudyResponses(
+    private static List<StudyResponse> getStudyResponses(
             final List<StudySummaryData> studiesSummaryData,
             final Map<Long, List<TagSummaryData>> studyTags
     ) {
         return studiesSummaryData.stream()
                 .map(studySummaryData -> new StudyResponse(studySummaryData, studyTags.get(studySummaryData.getId())))
                 .collect(Collectors.toList());
     }
+
+    private static StudySummaryData getLastStudyResponse(final List<StudySummaryData> studies) {
+        return studies.get(studies.size() - 1);
+    }
 }

backend/src/test/java/com/woowacourse/acceptance/AcceptanceTest.java

@@ -14,7 +14,6 @@
 import com.woowacourse.moamoa.MoamoaApplication;
 import com.woowacourse.moamoa.auth.service.oauthclient.response.GithubProfileResponse;
 import com.woowacourse.moamoa.auth.service.request.AccessTokenRequest;
-
 import io.restassured.RestAssured;
 import io.restassured.builder.RequestSpecBuilder;
 import io.restassured.specification.RequestSpecification;
@@ -34,7 +33,6 @@
 import org.springframework.restdocs.RestDocumentationContextProvider;
 import org.springframework.restdocs.RestDocumentationExtension;
 import org.springframework.test.web.client.MockRestServiceServer;
-import org.springframework.web.client.RestTemplate;
 
 @SpringBootTest(
         webEnvironment = WebEnvironment.RANDOM_PORT,
@@ -47,17 +45,14 @@ public class AcceptanceTest {
     protected RequestSpecification spec;
 
     @RegisterExtension
-    final RestDocumentationExtension restDocumentation = new RestDocumentationExtension (OUTPUT_DIRECTORY);
+    final RestDocumentationExtension restDocumentation = new RestDocumentationExtension(OUTPUT_DIRECTORY);
 
     @LocalServerPort
     protected int port;
 
     @Autowired
     private JdbcTemplate jdbcTemplate;
 
-    @Autowired
-    private RestTemplate restTemplate;
-
     @Autowired
     public SlackAlarmMockServer slackAlarmMockServer;