菜單樹形結(jié)構(gòu)

package com.yun.entity.vo;

import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

@Data
public class MenuVO implements Serializable {

    private static final long serialVersionUID = 1L;

    @ApiModelProperty(value = "主鍵")
    private Integer id;

    @ApiModelProperty(value = "菜單名稱")
    private String name;

    @ApiModelProperty(value = "菜單圖標(biāo)")
    private String icon;

    @ApiModelProperty(value = "菜單路由")
    private String link;

    @ApiModelProperty(value = "菜單索引")
    private String indexTag;

    @ApiModelProperty(value = "菜單類型斥杜，目錄：12801001窖贤，菜單：12801002，按鈕：12801003")
    private Integer type;

    @ApiModelProperty(value = "排序")
    private Integer sort;

    @ApiModelProperty(value = "狀態(tài)钝诚，啟用：12781001棘劣，停用：12781002")
    private Integer status;

    @ApiModelProperty(value = "權(quán)限標(biāo)識")
    private String permission;

    @ApiModelProperty(value = "父節(jié)點主鍵椰拒，-1為根節(jié)點")
    private Integer parentId;

    @ApiModelProperty(value = "用于前端顯示開關(guān)嫉称，status=12781001為true")
    private boolean enable;

    @ApiModelProperty(value = "菜單子表")
    private List<MenuVO> children = new ArrayList<>();
}

package com.yun.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.yun.constant.DictConstant;
import com.yun.entity.dto.UserDTO;
import com.yun.entity.po.MenuPO;
import com.yun.entity.vo.MenuVO;
import com.yun.mapper.MenuMapper;
import com.yun.service.MenuService;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * <p>
 * 菜單表 服務(wù)實現(xiàn)類
 * </p>
 *
 * @author CNSTT
 * @since 2023-01-21
 */
@Service
public class MenuServiceImpl extends ServiceImpl<MenuMapper, MenuPO> implements MenuService {

    /**
     * 菜單樹形查詢
     *
     * @param dto 傳參
     * @return List<MenuVO>
     */
    @Override
    public List<MenuVO> searchDefault(MenuDTO dto) {
        LambdaQueryWrapper<MenuPO> wrapper = new QueryWrapper<MenuPO>().lambda();
        // 查詢菜單或目錄
        wrapper.in(MenuPO::getType, DictConstant.DICT_MENU_TYPE_CATALOG, DictConstant.DICT_MENU_TYPE_MENU);
        wrapper.eq(MenuPO::getDeleteFlag, DictConstant.DICT_NO);
        List<MenuPO> menuList = baseMapper.selectList(wrapper);
        if (!CollectionUtils.isEmpty(menuList)) {
            // 樹形返回
            return packageListFunc(menuList);
        }
        return new ArrayList<>();
    }

    /**
     * 組裝菜單樹形結(jié)構(gòu)主方法
     *
     * @param menuList 全量數(shù)據(jù)
     * @return List<MenuVO>
     */
    private List<MenuVO> packageListFunc(List<MenuPO> menuList) {
        List<MenuVO> result = new ArrayList<>();
        List<MenuVO> list = convertResult(menuList);

        for (MenuVO node : list) {
            // parentId = -1為頂層目錄或菜單
            if (node.getParentId() == -1) {
                result.add(findChildren(node, list));
            }
        }
        return result;
    }

    /**
     * 遞歸查詢 - 根據(jù)父節(jié)點獲取子節(jié)點
     *
     * @param node 父節(jié)點
     * @param result 全量數(shù)據(jù)
     * @return MenuVO 填充完父節(jié)點
     */
    private MenuVO findChildren(MenuVO node, List<MenuVO> result) {
        for (MenuVO dto : result) {
            // 父節(jié)點的ID等于子節(jié)點的父節(jié)點ID
            if (node.getId().equals(dto.getParentId())) {
                if (node.getChildren() == null) {
                    node.setChildren(new ArrayList<>());
                }
                node.getChildren().add(findChildren(dto, result));
            }
        }
        return node;
    }

    /**
     * 公共方法 - 實體轉(zhuǎn)化VO出參集合
     *
     * @param menuList PO結(jié)果集
     * @return List<MenuVO>
     */
    private List<MenuVO> convertResult(List<MenuPO> menuList) {
        List<MenuVO> result = new ArrayList<>();
        if (!CollectionUtils.isEmpty(menuList)) {
            menuList.forEach(menuPO -> {
                MenuVO vo = new MenuVO();
                BeanUtils.copyProperties(menuPO, vo);
                vo.setEnable(vo.getStatus() != null && vo.getStatus() == DictConstant.DICT_YES);
                result.add(vo);
            });
        }
        return result;
    }
}