代码；生成树形结构 工具类及其用法

package com.sdyy.asset.dataeye.common.util;

import org.apache.commons.lang3.ArrayUtils;
import org.springframework.cglib.beans.BeanGenerator;
import org.springframework.cglib.beans.BeanMap;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class TreeFunction {
    private static volatile TreeFunction instance = null;
    private static TreeFunction getInstance(){
        if (instance == null) {
            synchronized (TreeFunction.class) {
                if (instance == null) {
                    instance = new TreeFunction();
                }
            }
        }
        return instance;
    }

    /**
     * 将列表转换为树
     * @param source 要转换的集合列表
     * @param rootNodeValue 根节点的parentId的值
     * @param idName 主键字段名
     * @param parentIdName 父节点字段名
     * @return
     */
    public static TreeNode transferToTree(List source,String rootNodeValue, String idName,String parentIdName){
       return getInstance().innerRecursive(source,rootNodeValue,idName,parentIdName);
    }

    private TreeNode innerRecursive(List obj,String rootNodeName, String idName, String parentIdName) {
        if(obj != null){
            TreeNode result = new TreeNode();
            coreRecursive(result,obj,rootNodeName,idName,parentIdName);
            return result;
        }
        return null;
    }

    private void coreRecursive(TreeNode result, List obj, Object parentId, String idName, String parentIdName){
        Iterator