[#44] 팔로우 구현 (#45)

* [#44] 팔로우  구현

- 팔로우 API, service 구현
- sendFollow -> follow로 변경

src/main/java/com/social/instagram/controller/FollowController.java

@@ -0,0 +1,29 @@
+package com.social.instagram.controller;
+
+import com.social.instagram.domain.Follow;
+import com.social.instagram.service.FollowService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+
+import static com.social.instagram.util.httpstatus.ResponseConstants.RESPONSE_ENTITY_CREATE;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/follows")
+public class FollowController {
+
+    private final FollowService followService;
+
+    @PostMapping
+    public ResponseEntity<Void> follow(@RequestBody Follow follow) {
+        followService.follow(follow);
+
+        return RESPONSE_ENTITY_CREATE;
+    }
+
+}

src/main/java/com/social/instagram/domain/Follow.java

@@ -0,0 +1,39 @@
+package com.social.instagram.domain;
+
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class Follow {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    private String userId;
+
+    private String followId;
+
+    @Builder
+    public Follow(String userId, String followId) {
+        this.userId = userId;
+        this.followId = followId;
+    }
+
+    public static Follow from(String userId, String followId) {
+        return Follow.builder()
+                .userId(userId)
+                .followId(followId)
+                .build();
+    }
+
+}

src/main/java/com/social/instagram/repository/FollowRepository.java

@@ -0,0 +1,8 @@
+package com.social.instagram.repository;
+
+import com.social.instagram.domain.Follow;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface FollowRepository extends JpaRepository<Follow, Long> {
+
+}

src/main/java/com/social/instagram/service/FollowService.java

@@ -0,0 +1,18 @@
+package com.social.instagram.service;
+
+import com.social.instagram.domain.Follow;
+import com.social.instagram.repository.FollowRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class FollowService {
+
+    private final FollowRepository followRepository;
+
+    public void follow(Follow follow) {
+        followRepository.save(follow);
+    }
+
+}