create comment

src/main/java/io/spring/api/CommentsApi.java

@@ -0,0 +1,70 @@
+package io.spring.api;
+
+import com.fasterxml.jackson.annotation.JsonRootName;
+import io.spring.api.exception.InvalidRequestException;
+import io.spring.api.exception.ResourceNotFoundException;
+import io.spring.application.comment.CommentData;
+import io.spring.application.comment.CommentQueryService;
+import io.spring.core.article.Article;
+import io.spring.core.article.ArticleRepository;
+import io.spring.core.comment.Comment;
+import io.spring.core.comment.CommentRepository;
+import io.spring.core.user.User;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.hibernate.validator.constraints.NotBlank;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.validation.BindingResult;
+import org.springframework.web.bind.annotation.PathVariable;
+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 javax.validation.Valid;
+import javax.xml.ws.Response;
+
+@RestController
+@RequestMapping(path = "/articles/{slug}/comments")
+public class CommentsApi {
+    private ArticleRepository articleRepository;
+    private CommentRepository commentRepository;
+    private CommentQueryService commentQueryService;
+
+    @Autowired
+    public CommentsApi(ArticleRepository articleRepository,
+                       CommentRepository commentRepository,
+                       CommentQueryService commentQueryService) {
+        this.articleRepository = articleRepository;
+        this.commentRepository = commentRepository;
+        this.commentQueryService = commentQueryService;
+    }
+
+    @PostMapping
+    public ResponseEntity<CommentData> createComment(@PathVariable("slug") String slug,
+                                                     @AuthenticationPrincipal User user,
+                                                     @Valid @RequestBody NewCommentParam newCommentParam,
+                                                     BindingResult bindingResult) {
+        Article article = findArticle(slug);
+        if (bindingResult.hasErrors()) {
+            throw new InvalidRequestException(bindingResult);
+        }
+        Comment comment = new Comment(newCommentParam.getBody(), user.getId(), article.getId());
+        commentRepository.save(comment);
+        return ResponseEntity.status(201).body(commentQueryService.findById(comment.getId(), user).get());
+    }
+
+    private Article findArticle(String slug) {
+        return articleRepository.findBySlug(slug).map(article -> article).orElseThrow(ResourceNotFoundException::new);
+    }
+}
+
+@Getter
+@NoArgsConstructor
+@JsonRootName("comment")
+class NewCommentParam {
+    @NotBlank(message = "can't be empty")
+    private String body;
+}

src/main/java/io/spring/application/comment/CommentData.java

@@ -0,0 +1,23 @@
+package io.spring.application.comment;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonRootName;
+import io.spring.application.profile.ProfileData;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.joda.time.DateTime;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@JsonRootName("comment")
+public class CommentData {
+    private String id;
+    private String body;
+    private String articleId;
+    private DateTime createdAt;
+    private DateTime updatedAt;
+    @JsonProperty("author")
+    private ProfileData profileData;
+}

src/main/java/io/spring/application/comment/CommentQueryService.java

@@ -0,0 +1,31 @@
+package io.spring.application.comment;
+
+import io.spring.application.profile.UserRelationshipQueryService;
+import io.spring.core.user.User;
+import org.springframework.stereotype.Service;
+
+import java.util.Optional;
+
+@Service
+public class CommentQueryService {
+    private CommentReadService commentReadService;
+    private UserRelationshipQueryService userRelationshipQueryService;
+
+    public CommentQueryService(CommentReadService commentReadService, UserRelationshipQueryService userRelationshipQueryService) {
+        this.commentReadService = commentReadService;
+        this.userRelationshipQueryService = userRelationshipQueryService;
+    }
+
+    public Optional<CommentData> findById(String id, User user) {
+        CommentData commentData = commentReadService.findById(id);
+        if (commentData == null) {
+            return Optional.empty();
+        } else {
+            commentData.getProfileData().setFollowing(
+                userRelationshipQueryService.isUserFollowing(
+                    user.getId(),
+                    commentData.getProfileData().getId()));
+        }
+        return Optional.ofNullable(commentData);
+    }
+}

src/main/java/io/spring/application/comment/CommentReadService.java

@@ -0,0 +1,10 @@
+package io.spring.application.comment;
+
+import org.apache.ibatis.annotations.Mapper;
+import org.springframework.stereotype.Component;
+
+@Component
+@Mapper
+public interface CommentReadService {
+    CommentData findById(String id);
+}

src/main/java/io/spring/core/comment/Comment.java

@@ -0,0 +1,27 @@
+package io.spring.core.comment;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import org.joda.time.DateTime;
+
+import java.util.UUID;
+
+@Getter
+@NoArgsConstructor
+@EqualsAndHashCode(of = "id")
+public class Comment {
+    private String id;
+    private String body;
+    private String userId;
+    private String articleId;
+    private DateTime createdAt;
+
+    public Comment(String body, String userId, String articleId) {
+        this.id = UUID.randomUUID().toString();
+        this.body = body;
+        this.userId = userId;
+        this.articleId = articleId;
+        this.createdAt = new DateTime();
+    }
+}

src/main/java/io/spring/core/comment/CommentRepository.java

@@ -0,0 +1,9 @@
+package io.spring.core.comment;
+
+import java.util.Optional;
+
+public interface  CommentRepository {
+    void save(Comment comment);
+
+    Optional<Comment> findById(String id);
+}

src/main/java/io/spring/infrastructure/comment/CommentMapper.java

@@ -0,0 +1,14 @@
+package io.spring.infrastructure.comment;
+
+import io.spring.core.comment.Comment;
+import org.apache.ibatis.annotations.Mapper;
+import org.apache.ibatis.annotations.Param;
+import org.springframework.stereotype.Component;
+
+@Component
+@Mapper
+public interface CommentMapper {
+    void insert(@Param("comment") Comment comment);
+
+    Comment findById(@Param("id") String id);
+}

src/main/java/io/spring/infrastructure/comment/MyBatisCommentRepository.java

@@ -0,0 +1,28 @@
+package io.spring.infrastructure.comment;
+
+import io.spring.core.comment.Comment;
+import io.spring.core.comment.CommentRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.Optional;
+
+@Component
+public class MyBatisCommentRepository implements CommentRepository {
+    private CommentMapper commentMapper;
+
+    @Autowired
+    public MyBatisCommentRepository(CommentMapper commentMapper) {
+        this.commentMapper = commentMapper;
+    }
+
+    @Override
+    public void save(Comment comment) {
+        commentMapper.insert(comment);
+    }
+
+    @Override
+    public Optional<Comment> findById(String id) {
+        return Optional.ofNullable(commentMapper.findById(id));
+    }
+}