create comment

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));
+    }
+}