[feat] #21 팔로우 도메인 개발

src/main/java/com/leets/X/domain/follow/controller/FollowController.java

@@ -0,0 +1,49 @@
+package com.leets.X.domain.follow.controller;
+
+import com.leets.X.domain.follow.dto.response.FollowResponse;
+import com.leets.X.domain.follow.service.FollowService;
+import com.leets.X.global.common.response.ResponseDto;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+import static com.leets.X.domain.follow.controller.ResponseMessage.*;
+
+@Tag(name = "FOLLOW")
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/v1/follows")
+public class FollowController {
+    private final FollowService followService;
+
+    @PostMapping("/{userId}")
+    @Operation(summary = "팔로우 하기")
+    public ResponseDto<String> follow(@PathVariable Long userId, @AuthenticationPrincipal String email){
+        followService.follow(userId, email);
+        return ResponseDto.response(FOLLOW_SUCCESS.getCode(), FOLLOW_SUCCESS.getMessage());
+    }
+
+    @GetMapping("follower/{userId}")
+    @Operation(summary = "해당 유저의 팔로워 조회(해당 유저를 팔로우 하는 사용자 목록")
+    public ResponseDto<List<FollowResponse>> getFollowers(@PathVariable Long userId){
+        return ResponseDto.response(GET_FOLLOWER_SUCCESS.getCode(), GET_FOLLOWER_SUCCESS.getMessage(), followService.getFollowers(userId));
+    }
+
+    @GetMapping("following/{userId}")
+    @Operation(summary = "해당 유저의 팔로잉 조회(해당 유저가 팔로우 하는 사용자 목록")
+    public ResponseDto<List<FollowResponse>> getFollowings(@PathVariable Long userId){
+        return ResponseDto.response(GET_FOLLOWING_SUCCESS.getCode(), GET_FOLLOWING_SUCCESS.getMessage(), followService.getFollowings(userId));
+    }
+
+    @DeleteMapping("/{userId}")
+    @Operation(summary = "언팔로우 하기")
+    public ResponseDto<String> unfollow(@PathVariable Long userId, @AuthenticationPrincipal String email){
+        followService.unfollow(userId, email);
+        return ResponseDto.response(UNFOLLOW_SUCCESS.getCode(), UNFOLLOW_SUCCESS.getMessage());
+    }
+
+}

src/main/java/com/leets/X/domain/follow/controller/ResponseMessage.java

@@ -0,0 +1,17 @@
+package com.leets.X.domain.follow.controller;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public enum ResponseMessage {
+
+    FOLLOW_SUCCESS(200, "팔로우에 성공했습니다."),
+    GET_FOLLOWER_SUCCESS(200, "팔로워 목록 조회에 성공했습니다."),
+    GET_FOLLOWING_SUCCESS(200, "팔로잉 목록 조회에 성공했습니다."),
+    UNFOLLOW_SUCCESS(200, "언팔로우에 성공했습니다.");
+
+    private final int code;
+    private final String message;
+}

src/main/java/com/leets/X/domain/follow/domain/Follow.java

@@ -1,2 +1,35 @@
-package com.leets.X.domain.follow.domain;public class Follow {
+package com.leets.X.domain.follow.domain;
+
+import com.leets.X.domain.user.domain.User;
+import com.leets.X.global.common.domain.BaseTimeEntity;
+import jakarta.persistence.*;
+import lombok.*;
+
+@Entity
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor
+@Builder
+@Getter
+public class Follow extends BaseTimeEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "follow_id")
+    private Long id;
+
+    @ManyToOne
+    @JoinColumn(name = "follower_id")
+    private User follower;
+
+    @ManyToOne
+    @JoinColumn(name = "followed_id")
+    private User followed;
+
+    public static Follow of(User follower, User followed) {
+        return Follow.builder()
+                .follower(follower)
+                .followed(followed)
+                .build();
+    }
+
 }

src/main/java/com/leets/X/domain/follow/dto/response/FollowResponse.java

@@ -0,0 +1,22 @@
+package com.leets.X.domain.follow.dto.response;
+
+import com.leets.X.domain.user.domain.User;
+import lombok.Builder;
+
+@Builder
+public record FollowResponse(
+        Long id,
+        String name,
+        String customId,
+        String introduce
+//        boolean followStatus
+) {
+    public static FollowResponse from(User user) {
+        return FollowResponse.builder()
+                .id(user.getId())
+                .name(user.getName())
+                .customId(user.getCustomId())
+                .introduce(user.getIntroduce())
+                .build();
+    }
+}

src/main/java/com/leets/X/domain/follow/exception/AlreadyFollowException.java

@@ -0,0 +1,12 @@
+package com.leets.X.domain.follow.exception;
+
+import com.leets.X.global.common.exception.BaseException;
+
+import static com.leets.X.domain.follow.exception.ErrorMessage.*;
+
+public class AlreadyFollowException extends BaseException {
+    public AlreadyFollowException() {
+        super(ALREADY_FOLLOW.getCode(), ALREADY_FOLLOW.getMessage());
+    }
+}
+

src/main/java/com/leets/X/domain/follow/exception/ErrorMessage.java

@@ -0,0 +1,20 @@
+package com.leets.X.domain.follow.exception;
+
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public enum ErrorMessage {
+
+    ALREADY_FOLLOW(400,"이미 팔로우한 상태입니다."),
+    INVALID_FOLLOW(400, "자기 자신은 팔로우 할 수 없습니다."),
+    FOLLOW_NOT_FOUND(404, "팔로우 데이터를 찾을 수 없습니다."),
+    INVALID_UNFOLLOW(400, "팔로우 하지 않은 상대는 언팔로우 할 수 없습니다.");
+
+
+    private final int code;
+    private final String message;
+
+}

src/main/java/com/leets/X/domain/follow/exception/FollowNotFoundException.java

@@ -0,0 +1,12 @@
+package com.leets.X.domain.follow.exception;
+
+import com.leets.X.global.common.exception.BaseException;
+
+import static com.leets.X.domain.follow.exception.ErrorMessage.*;
+
+public class FollowNotFoundException extends BaseException {
+    public FollowNotFoundException() {
+        super(FOLLOW_NOT_FOUND.getCode(), FOLLOW_NOT_FOUND.getMessage());
+    }
+}
+

src/main/java/com/leets/X/domain/follow/exception/InvalidFollowException.java

@@ -0,0 +1,11 @@
+package com.leets.X.domain.follow.exception;
+
+import com.leets.X.global.common.exception.BaseException;
+
+import static com.leets.X.domain.follow.exception.ErrorMessage.*;
+
+public class InvalidFollowException extends BaseException {
+    public InvalidFollowException() {
+        super(INVALID_FOLLOW.getCode(), INVALID_FOLLOW.getMessage());
+    }
+}

src/main/java/com/leets/X/domain/follow/exception/InvalidUnfollowException.java

@@ -0,0 +1,11 @@
+package com.leets.X.domain.follow.exception;
+
+import com.leets.X.global.common.exception.BaseException;
+
+import static com.leets.X.domain.follow.exception.ErrorMessage.*;
+
+public class InvalidUnfollowException extends BaseException {
+    public InvalidUnfollowException() {
+        super(INVALID_UNFOLLOW.getCode(), INVALID_UNFOLLOW.getMessage());
+    }
+}

src/main/java/com/leets/X/domain/follow/repository/FollowRepository.java

@@ -0,0 +1,21 @@
+package com.leets.X.domain.follow.repository;
+
+import com.leets.X.domain.follow.domain.Follow;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface FollowRepository extends JpaRepository<Follow, Long> {
+
+    Optional<Follow> findByFollowerIdAndFollowedId(Long followerId, Long followedId);
+
+    // followerId가 포함된 객체 리스트 반환
+    List<Follow> findByFollowerId(Long followerId);
+
+    // followedId가 포함된 객체 리스트 반환
+    List<Follow> findByFollowedId(Long followedId);
+
+    boolean existsByFollowerIdAndFollowedId(Long followerId, Long followedId);
+
+}

src/main/java/com/leets/X/domain/follow/service/FollowService.java

@@ -0,0 +1,96 @@
+package com.leets.X.domain.follow.service;
+
+import com.leets.X.domain.follow.domain.Follow;
+import com.leets.X.domain.follow.dto.response.FollowResponse;
+import com.leets.X.domain.follow.exception.AlreadyFollowException;
+import com.leets.X.domain.follow.exception.FollowNotFoundException;
+import com.leets.X.domain.follow.exception.InvalidFollowException;
+import com.leets.X.domain.follow.exception.InvalidUnfollowException;
+import com.leets.X.domain.follow.repository.FollowRepository;
+import com.leets.X.domain.user.domain.User;
+import com.leets.X.domain.user.service.UserService;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class FollowService {
+    private final FollowRepository followRepository;
+    private final UserService userService;
+
+    @Transactional
+    public void follow(Long userId, String email){
+        User follower = userService.find(email);
+        User followed = userService.find(userId);
+
+        validate(follower.getId(), followed.getId());
+
+        Follow follow = followRepository.save(Follow.of(follower, followed));
+
+        follower.addFollowing(follow);
+        followed.addFollower(follow);
+    }
+
+    public List<FollowResponse> getFollowers(Long userId){
+        User user = userService.find(userId);
+
+        List<Follow> followerList = user.getFollowerList();
+
+        return followerList.stream()
+                .map(follow -> {
+                    return FollowResponse.from(follow.getFollower()); })
+                .toList();
+    }
+
+    public List<FollowResponse> getFollowings(Long userId){
+        User user = userService.find(userId);
+
+        List<Follow> followingList = user.getFollowingList();
+
+        return followingList.stream()
+                .map(follow -> {
+                    return FollowResponse.from(follow.getFollowed()); })
+                .toList();
+    }
+
+    @Transactional
+    public void unfollow(Long userId, String email){
+        User follower = userService.find(email);
+        User followed = userService.find(userId);
+
+        Follow follow = check(follower.getId(), followed.getId());
+
+        follower.removeFollowing(follow);
+        followed.removeFollower(follow);
+
+        followRepository.delete(follow);
+    }
+
+    public Follow find(Long followerId, Long followedId){
+        return followRepository.findByFollowerIdAndFollowedId(followerId, followedId)
+                .orElseThrow(FollowNotFoundException::new);
+    }
+
+    // 기존 팔로우 정보가 있는지, 나한테 요청을 하지 않는지 검증
+    private void validate(Long followerId, Long followedId){
+        if(followRepository.existsByFollowerIdAndFollowedId(followerId, followedId)){
+            throw new AlreadyFollowException();
+        }
+        if(followerId.equals(followedId)){
+            throw new InvalidFollowException();
+        }
+    }
+
+    // 팔로우 되어 있는지 확인
+    private Follow check(Long followerId, Long followedId){
+        if(!followRepository.existsByFollowerIdAndFollowedId(followerId, followedId)){
+            throw new InvalidUnfollowException();
+        }
+        return find(followerId, followedId);
+    }
+
+}

src/main/java/com/leets/X/domain/user/domain/User.java

@@ -1,12 +1,15 @@
 package com.leets.X.domain.user.domain;
 
+import com.leets.X.domain.follow.domain.Follow;
 import com.leets.X.domain.user.dto.request.UserInitializeRequest;
 import com.leets.X.domain.user.dto.request.UserUpdateRequest;
 import com.leets.X.global.common.domain.BaseTimeEntity;
 import jakarta.persistence.*;
 import lombok.*;
 
 import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.List;
 
 @Entity
 // mysql에서 user 테이블이 존재 하기 때문에 다른 이름으로 지정
@@ -46,6 +49,12 @@ public class User extends BaseTimeEntity {
 
 //    private Image image;
 
+    @OneToMany(mappedBy = "followed", cascade = CascadeType.REMOVE, orphanRemoval = true)
+    private List<Follow> followerList = new ArrayList<>();
+
+    @OneToMany(mappedBy = "follower", cascade = CascadeType.REMOVE, orphanRemoval = true)
+    private List<Follow> followingList = new ArrayList<>();
+
     public void initProfile(UserInitializeRequest dto){
         this.birth = dto.birth();
         this.customId = dto.customId();
@@ -58,4 +67,22 @@ public void update(UserUpdateRequest dto){
         this.webSite = dto.webSite();
     }
 
+    public void addFollower(Follow follow) {
+        this.followerList.add(follow);
+    }
+
+    public void addFollowing(Follow follow) {
+        this.followingList.add(follow);
+    }
+
+    public void removeFollower(Follow follow) {
+        this.followerList.remove(follow);
+    }
+
+    public void removeFollowing(Follow follow) {
+        this.followingList.remove(follow);
+    }
+
+
+
 }

src/main/java/com/leets/X/domain/user/service/UserService.java

@@ -77,6 +77,11 @@ public UserProfileResponse getProfile(Long userId, String email){
         // 아니라면 false
         return UserProfileResponse.from(user, false);
     }
+//
+//    @Transactional
+//    public void delete(Long userId){
+//        userRepository.deleteById(userId);
+//    }
 
     private UserSocialLoginResponse loginUser(String email) {
         User user = find(email);
@@ -111,6 +116,11 @@ public User find(String email){
                 .orElseThrow(UserNotFoundException::new);
     }
 
+    public User find(Long userId){
+        return userRepository.findById(userId)
+                .orElseThrow(UserNotFoundException::new);
+    }
+
     public boolean existUser(String email){
         return userRepository.existsByEmail(email);
     }