[#771] Pagination 조회 쿼리 PK 기반 수정

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/application/PostFeedService.java

@@ -1,7 +1,6 @@
 package com.woowacourse.pickgit.post.application;
 
 
-import com.woowacourse.pickgit.exception.authentication.UnauthorizedException;
 import com.woowacourse.pickgit.exception.post.PostNotFoundException;
 import com.woowacourse.pickgit.exception.user.UserNotFoundException;
 import com.woowacourse.pickgit.post.application.dto.PostDtoAssembler;
@@ -39,7 +38,9 @@ public List<PostResponseDto> allHomeFeed(HomeFeedRequestDto homeFeedRequestDto)
         Pageable pageable = homeFeedRequestDto.getPageable();
 
         if (homeFeedRequestDto.isGuest()) {
-            return PostDtoAssembler.postResponseDtos(null, postRepository.findAllPosts(pageable));
+            return PostDtoAssembler.postResponseDtos(null,
+                postRepository.findAllPostsToBe(homeFeedRequestDto.getLastPostId(), pageable)
+            );
         }
 
         User requestUser = findUserByName(homeFeedRequestDto.getRequestUserName());

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/application/dto/request/HomeFeedRequestDto.java

@@ -9,7 +9,8 @@ public class HomeFeedRequestDto {
 
     private String requestUserName;
     private boolean isGuest;
-    Pageable pageable;
+    private Pageable pageable;
+    private Long lastPostId;
 
     private HomeFeedRequestDto() {
     }
@@ -25,6 +26,18 @@ public HomeFeedRequestDto(AppUser appUser, Pageable pageable) {
         this.pageable = pageable;
     }
 
+    public HomeFeedRequestDto(AppUser appUser, Pageable pageable, Long lastPostId) {
+        if(appUser.isGuest()) {
+            requestUserName = null;
+        } else {
+            requestUserName = appUser.getUsername();
+        }
+
+        this.isGuest = appUser.isGuest();
+        this.pageable = pageable;
+        this.lastPostId = lastPostId;
+    }
+
     public HomeFeedRequestDto(String requestUserName, boolean isGuest, Pageable pageable) {
         this.requestUserName = requestUserName;
         this.isGuest = isGuest;
@@ -42,4 +55,8 @@ public boolean isGuest() {
     public Pageable getPageable() {
         return pageable;
     }
+
+    public Long getLastPostId() {
+        return lastPostId;
+    }
 }

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/domain/repository/PostRepository.java

@@ -14,6 +14,9 @@ public interface PostRepository extends JpaRepository<Post, Long> {
     @Query("select p from Post p left join fetch p.user order by p.createdAt desc")
     List<Post> findAllPosts(Pageable pageable);
 
+    @Query("select p from Post p left join fetch p.user where p.id < :postId order by p.id desc")
+    List<Post> findAllPostsToBe(@Param("postId") Long postId, Pageable pageable);
+
     @Query("select p from Post p where p.user = :user order by p.createdAt desc")
     List<Post> findAllPostsByUser(@Param("user") User user, Pageable pageable);
 

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/presentation/PostController.java

@@ -17,7 +17,6 @@
 import com.woowacourse.pickgit.post.presentation.dto.request.PostUpdateRequest;
 import com.woowacourse.pickgit.post.presentation.dto.response.LikeResponse;
 import com.woowacourse.pickgit.post.presentation.dto.response.LikeUsersResponse;
-import com.woowacourse.pickgit.post.presentation.dto.response.PostResponse;
 import com.woowacourse.pickgit.post.presentation.dto.response.PostUpdateResponse;
 import com.woowacourse.pickgit.post.presentation.dto.response.RepositoryResponse;
 import java.net.URI;
@@ -145,9 +144,7 @@ public ResponseEntity<Void> delete(
 
         return ResponseEntity.noContent().build();
     }
-
-
-
+
     @ForLoginAndGuestUser
     @GetMapping("/posts/{postId}/likes")
     public ResponseEntity<List<LikeUsersResponse>> searchLikeUsers(

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/presentation/PostFeedController.java

@@ -40,14 +40,15 @@ public class PostFeedController {
     public ResponseEntity<List<PostResponse>> readHomeFeed(
         @Authenticated AppUser appUser,
         @PageableDefault Pageable pageable,
+        @RequestParam(required = false) Long lastPostId,
         @RequestParam(required = false, defaultValue = "all") String type
     ) {
         FeedType selectedFeedType = feedTypes.stream()
             .filter(feedType -> feedType.isSatisfiedBy(type))
             .findAny()
             .orElseThrow(HomeFeedTypeException::new);
 
-        HomeFeedRequestDto homeFeedRequestDto = new HomeFeedRequestDto(appUser, pageable);
+        HomeFeedRequestDto homeFeedRequestDto = new HomeFeedRequestDto(appUser, pageable, lastPostId);
         List<PostResponseDto> postResponseDtos = selectedFeedType.find(homeFeedRequestDto);
 
         List<PostResponse> postResponses = PostAssembler.postResponses((postResponseDtos));