java递归设置层级菜单的实现

package com.eleven;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.util.StrUtil;
import lombok.AllArgsConstructor;
import lombok.Data;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;


public class ElevenTest {
    public static void main(String[] args) {
        TestChild one = new TestChild("1","1",null);
        TestChild two = new TestChild("2","2","1");
        TestChild sex = new TestChild("3","3","2");
        List<TestChild> list = new ArrayList<>(3);
        Collections.addAll(list,one,two,sex);
        List<TestChild> tree = getTree(list);
        System.out.println(tree);
    }

    public static List<TestChild> getTree(List<TestChild> testChildList){
        List<TestChild> result = new ArrayList<>();
        for (TestChild testChild : testChildList) {
            if(StrUtil.isBlank(testChild.getParentId())){
                result.add(testChild);
            }
        }
        testChildList.removeAll(result);
        for (TestChild testChild : result) {
            setChildren(testChild,testChildList);
        }
        return result;
    }

    public static void setChildren(TestChild parent,List<TestChild> list){
        List<TestChild> childList = new ArrayList<>();
        for(Iterator<TestChild> iterator = list.iterator();iterator.hasNext();){
            TestChild next = iterator.next();
            if(parent.getCode().equals(next.getParentId())){
                childList.add(next);
                iterator.remove();
            }
        }

        parent.setChildren(childList);
        
   
        if(CollUtil.isNotEmpty(list)) {
            for (TestChild testChild : childList) {
                setChildren(testChild, list);
            }
        }
    }

}

@Data
@AllArgsConstructor
class TestChild{
    private String name;

    private String code;

    private String parentId;

    List<TestChild> children;

    public TestChild(String name,String code,String parentId){
        this.name = name;
        this.code = code;
        this.parentId = parentId;
    }
}