src/main/java/com/example/myproject/service/CommentService.java

package com.example.myproject.service;

import com.example.myproject.entity.Comments;
import com.example.myproject.entity.Post;
import com.example.myproject.entity.Users;
import com.example.myproject.repository.CommentRepository;
import com.example.myproject.repository.PostRepository;
import com.example.myproject.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

@Service
public class CommentService {

    @Autowired
    private CommentRepository commentRepository;

    @Autowired
    private PostRepository postRepository;

    @Autowired
    private UserRepository userRepository;

    // 添加评论
    public void addComment(Long postId, Comments comment) {
        try {
            // 查找帖子
            Post post = postRepository.findById(postId).orElseThrow(() -> {
                throw new RuntimeException("Post with ID " + postId + " not found");
            });

            // 查找用户
            Users user = userRepository.findById(comment.getUserId()).orElseThrow(() -> {
                throw new RuntimeException("User with ID " + comment.getUserId() + " not found");
            });

            // 设置评论的相关属性
            comment.setPost(post);
            comment.setUserId(user.getUserId());
            comment.setCommentTime(new java.util.Date());

            if (comment.getParentComment() != null && comment.getParentComment() != 0) {
                // 查找父评论
                Comments parentComment = commentRepository.findById(comment.getParentComment())
                        .orElseThrow(() -> new RuntimeException("Parent comment with ID " + comment.getParentComment() + " not found"));
                comment.setParentComment(parentComment.getCommentId());  // 设置父评论 ID
            } else {
                comment.setParentComment(0L);  // 设置为 0，表示没有父评论
            }

            // 保存评论
            commentRepository.save(comment);
        } catch (Exception e) {
            // 捕获任何异常并打印堆栈信息
            e.printStackTrace();
            throw new RuntimeException("An error occurred while adding the comment: " + e.getMessage());
        }
    }

    // 获取指定帖子的所有评论
    public List<Map<String, Object>> getCommentsByPostId(Long postId) {
        List<Comments> comments = commentRepository.findAll()
                .stream()
                .filter(comment -> comment.getPost().getPostNo().equals(postId))  // 通过 post 的 postNo 过滤评论
                .collect(Collectors.toList());

        if (comments.isEmpty()) {
            return new ArrayList<>();
        }

        List<Map<String, Object>> result = new ArrayList<>();
        for (Comments comment : comments) {
            Map<String, Object> commentData = new LinkedHashMap<>();
            commentData.put("commentId", comment.getCommentId());
            commentData.put("post_id", comment.getPost().getPostNo());
            commentData.put("userId", comment.getUserId());

            Users user = userRepository.findById(comment.getUserId()).orElse(null);
            commentData.put("nickname", user != null ? user.getUsername() : null);
            commentData.put("avatar_url", user != null ? user.getAvatarUrl() : null);

            commentData.put("content", comment.getContent());
            commentData.put("isAnonymous", comment.getIsAnonymous());
            commentData.put("likesCount", comment.getLikesCount());
            commentData.put("replyCount", comment.getReplyCount());
            commentData.put("commentTime", comment.getCommentTime());
            commentData.put("parentComment", comment.getParentComment());

            Map<String, Object> parentCommentData = getParentCommentData(comment.getParentComment());
            commentData.put("parentCommentData", parentCommentData);

            result.add(commentData);
        }

        return result;
    }

    // 递归查找父评论的内容
    private Map<String, Object> getParentCommentData(Long parentCommentId) {
        Map<String, Object> parentCommentData = new LinkedHashMap<>();
        if (parentCommentId != null && parentCommentId != 0) {
            // 查找父评论
            Comments parentComment = commentRepository.findById(parentCommentId).orElse(null);
            if (parentComment != null) {
                parentCommentData.put("commentId", parentComment.getCommentId());
                parentCommentData.put("content", parentComment.getContent());
                parentCommentData.put("userId", parentComment.getUserId());

                Users user = userRepository.findById(parentComment.getUserId()).orElse(null);
                parentCommentData.put("nickname", user != null ? user.getUsername() : null);
                parentCommentData.put("avatar_url", user != null ? user.getAvatarUrl() : null);

                Map<String, Object> grandParentData = getParentCommentData(parentComment.getParentComment());
                parentCommentData.put("parentCommentData", grandParentData);
            }
        }
        return parentCommentData;
    }
}