IESExtension/src/main/java/cn/teammodel/service/impl/EvaluationServiceImpl.java

package cn.teammodel.service.impl;

import cn.teammodel.common.PK;
import cn.teammodel.dao.EvaluationRepository;
import cn.teammodel.model.dto.GetEvaluateTreeDto;
import cn.teammodel.model.entity.Evaluation;
import cn.teammodel.model.entity.EvaluationTreeNode;
import cn.teammodel.service.EvaluationService;
import org.apache.commons.lang3.ObjectUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;

/**
 * @author winter
 * @create 2023-11-20 17:47
 */
@Service
public class EvaluationServiceImpl implements EvaluationService {
    @Resource
    private EvaluationRepository evaluationRepository;

    @Override
    public List<EvaluationTreeNode> getTree(GetEvaluateTreeDto getEvaluateTreeDto) {
        String schoolId = getEvaluateTreeDto.getSchoolId();
        String periodId = getEvaluateTreeDto.getPeriodId();
        periodId = StringUtils.isEmpty(periodId) ? "default" : periodId;

        Evaluation evaluation = evaluationRepository.findBySchoolIdAndPeriodId(schoolId, periodId, PK.PK_SCHOOL);
        List<EvaluationTreeNode> nodes = evaluation.getNodes();
        List<EvaluationTreeNode> trees = this.buildTree(nodes);
        evaluation.setNodes(trees);
        return trees;
    }

    @Override
    public List<EvaluationTreeNode> buildTree(List<EvaluationTreeNode> nodes) {
        List<EvaluationTreeNode> parents = new ArrayList<>();
        // pid 为 null 或者 "" 则为 parents
        for (EvaluationTreeNode node : nodes) {
            if (StringUtils.isBlank(node.getPid())) {
                parents.add(node);
            }
        }
        // 迭代构建孩子节点
        for (EvaluationTreeNode parent : parents) {
            buildChildren(parent, nodes);
        }
        return parents;
    }

    @Override
    public void flattenTree(List<EvaluationTreeNode> trees, List<EvaluationTreeNode> nodes) {
        // 递归结束条件
        if (ObjectUtils.isEmpty(trees)) return;

        // 这里的每个 tree 都是组装好的树,区别于单个节点
        for (EvaluationTreeNode tree : trees) {
            // 递归
            flattenTree(tree.getChildren(), nodes);
            // 回溯时删除 children,添加进列表
            tree.setChildren(null);
            nodes.add(tree);
        }
    }

    /**
     * 递归的构建父亲节点的孩子,以及孩子的孩子 (理论支持无极树,但应该考虑是否增加递归深度)
     */
    private void buildChildren(EvaluationTreeNode parent, List<EvaluationTreeNode> nodes) {
        List<EvaluationTreeNode> children = getChildren(parent, nodes);
        if (children.size() == 0) return;

        parent.setChildren(children);
        for (EvaluationTreeNode child : children) {
            // 如果子节点还有孩子的话,就继续递归构建
            if (getChildren(child, nodes).size() > 0) {
                buildChildren(child, nodes);
            }
        }

    }

    private List<EvaluationTreeNode> getChildren(EvaluationTreeNode parent, List<EvaluationTreeNode> nodes) {
        List<EvaluationTreeNode> children = new ArrayList<>();
        for (EvaluationTreeNode node : nodes) {
            if (StringUtils.isNotBlank(node.getPid()) && node.getPid().equals(parent.getId())) {
                children.add(node);
            }
        }
        return children;
    }
}