java 递归生成树形结构

package com.lsn.ams;

import com.alibaba.fastjson.JSONArray;
import java.util.*;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

public class Test {


    public static void main(String[] args) {
        List data = new ArrayList();

        Tree tree = new Tree();
        tree.setId("1");
        tree.setPid("0");
        tree.setName("系统管理");

        data.add(tree);

        tree = new Tree();

        tree.setId("2");
        tree.setPid("1");
        tree.setName("管理员列表");
        data.add(tree);

        tree = new Tree();
        tree.setId("3");
        tree.setPid("2");
        tree.setName("新增管理员");
        data.add(tree);

        tree = new Tree();
        tree.setPid("0");
        tree.setId("4");
        tree.setName("导览管理");
        data.add(tree);

        tree = new Tree();
        tree.setId("5");
        tree.setPid("4");
        tree.setName("POI管理");
        data.add(tree);


        MenuTree menuTree = new MenuTree();
        List