spzx/spzx-common/common-service/src/main/java/com/atguigu/utils/MenuHelper.java

package com.atguigu.utils;


import com.atguigu.spzx.model.entity.system.SysMenu;
import com.atguigu.spzx.model.vo.system.SysMenuVo;
import org.springframework.util.CollectionUtils;

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


public class MenuHelper {
    /**
     * 构建树型结构
     *
     * @param sysMenuList 系统菜单列表
     * @return 菜单结构列表
     */
    public static List<SysMenu> buildTree(List<SysMenu> sysMenuList) {
        ArrayList<SysMenu> tress = new ArrayList<>();
        // 把菜单数据进行遍历
        sysMenuList.forEach(sysMenu -> {
            if (sysMenu.getParentId() == 0) tress.add(getChildren(sysMenu, sysMenuList));
        });
        return tress;
    }

    /**
     * 构建递归循环
     *
     * @param sysMenu     当前菜单对象
     * @param sysMenuList 全部菜单列表
     * @return 菜单
     */
    private static SysMenu getChildren(SysMenu sysMenu, List<SysMenu> sysMenuList) {
        // 遍历所有菜单数据，判断id和parentID对应关系
        sysMenu.setChildren(new ArrayList<>());

        sysMenuList.forEach(menu -> {
            if (menu.getChildren() == null) menu.setChildren(new ArrayList<>());
            if (sysMenu.getId().equals(menu.getParentId())) {
                sysMenu.getChildren().add(getChildren(menu, sysMenuList));
            }
        });

        return sysMenu;
    }


    /**
     * 将List<SysMenu>对象转换成List<SysMenuVo>对象
     *
     * @param menus 全部菜单列表
     * @return 系统菜单响应结果实体类列表
     */
    public static List<SysMenuVo> buildMenus(List<SysMenu> menus) {
        LinkedList<SysMenuVo> sysMenuVos = new LinkedList<>();
        
        menus.forEach(menu -> {
            SysMenuVo menuVo = new SysMenuVo();
            menuVo.setTitle(menu.getTitle());
            menuVo.setName(menu.getComponent());

            List<SysMenu> children = menu.getChildren();
            if (!CollectionUtils.isEmpty(children)) {
                menuVo.setChildren(buildMenus(children));
            }
            sysMenuVos.add(menuVo);
        });
        return sysMenuVos;
    }
}