hutool的树形工具类-TreeUtil

package com.fayi.hutool.TreeUtil;
 
import cn.hutool.core.lang.tree.Tree;
import cn.hutool.core.lang.tree.TreeNodeConfig;
import cn.hutool.core.lang.tree.TreeUtil;
import cn.hutool.json.JSONUtil;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
 
import java.util.ArrayList;
import java.util.List;
 
public class Demo {
 
    public static void main(String[] args) {
        List<User> users = new ArrayList<>();
        users.add(new User("1", "", "0", "手机"));
        users.add(new User("2", "", "1", "小米"));
        users.add(new User("3", "", "1", "华为"));
        users.add(new User("4", "", "0", "水果"));
        users.add(new User("5", "", "4", "香蕉"));
        users.add(new User("6", "", "4", "菠萝"));
        TreeNodeConfig config = new TreeNodeConfig();
        List<Tree<String>> treeList = TreeUtil.build(users, "0", config, (treeNode, tree) -> {
            tree.setId(treeNode.getId());
            tree.setParentId(treeNode.getPid());
            tree.setName(treeNode.getName());
        });
        System.out.println(JSONUtil.toJsonStr(treeList));
 
        // 自定义字段名,userId 对应pid
        users.clear();
        users.add(new User("1", "10", "0", "手机"));
        users.add(new User("2", "20", "10", "小米"));
        users.add(new User("3", "30", "10", "华为"));
        users.add(new User("4", "40", "0", "水果"));
        users.add(new User("5", "50", "40", "香蕉"));
        users.add(new User("6", "60", "40", "菠萝"));
        config.setIdKey("userId");
        treeList = TreeUtil.build(users, "0", config, (treeNode, tree) -> {
            tree.setId(treeNode.getUserId());
            tree.setParentId(treeNode.getPid());
            tree.setName(treeNode.getName());
            tree.putExtra("id", treeNode.getId());
        });
        System.out.println(JSONUtil.toJsonStr(treeList));
    }
 
}
 
@NoArgsConstructor
@AllArgsConstructor
@Data
class User {
 
    private String id;
    private String userId;
    private String pid;
    private String name;
}

可以灵活配置，树形结果返回，不再需要自己写递归了

Hutool参考文档