Java 生成树结构（二）

package pit.common.utils;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.util.StrUtil;
import pit.common.web.response.Ztree;

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

public class ZtreeUtils {

    
    public static List getZreeList(List ztreeList) {
        List parents = getParents(ztreeList);
//        List parents = ztreeList.stream()
//                .filter(f-> StringUtils.isEmpty(f.getPId()) || "null".equals(f.getPId()))
//                .collect(Collectors.toList());

        for (Ztree p : parents) {
            p.setIsOpen(false);
            List childPerms = getChildPerms(ztreeList, p.getId());
            if(childPerms == null){
                childPerms = new ArrayList<>();
            }
            p.setChildren(childPerms);
        }

        return parents;


    }

    
    private static List getParents(List treeList) {
        if (treeList == null || treeList.size() < 1) {
            return Collections.emptyList();
        }
        List ids = treeList.stream().map(i -> i.getId())
                .filter(StrUtil::isNotEmpty).distinct()
                .collect(Collectors.toList());
        //pid在ids里面找不到的

        return treeList.stream().filter(i -> !ids.contains(i.getPId()))
                .collect(Collectors.toList());
    }

    
    public static List getChildPerms(List list, String parentId) {
        parentId = null == parentId ? "" : parentId;
        List returnList = new ArrayList<>();
        for (Iterator iterator = list.iterator(); iterator.hasNext(); ) {
            Ztree t = iterator.next();
            // 一、根据传入的某个父节点ID,遍历该父节点的所有子节点
            if (parentId.equals(t.getPId())) {
                returnList.add(t);
                recursionFn(list, t);
            }
        }
        return returnList;
    }


    
    private static void recursionFn(List list, Ztree t) {
        // 得到子节点列表
        List childList = getChildList(list, t);
        if(childList == null){
            childList = new ArrayList<>();
        }
        t.setChildren(childList);
        for (Ztree tChild : childList) {
            if (hasChild(list, tChild)) {
                // 判断是否有子节点
                Iterator it = childList.iterator();
                while (it.hasNext()) {
                    Ztree n =  it.next();
                    recursionFn(list, n);
                }
            }
        }
    }


    
    private static List getChildList(List list, Ztree t) {
        List tlist = new ArrayList<>();
        Iterator it = list.iterator();
        while (it.hasNext()) {
            Ztree n = it.next();
            if (t.getId().equals(n.getPId())) {
                tlist.add(n);
            }
        }
        return tlist;
    }

    
    private static boolean hasChild(List list, Ztree t) {
        for (Ztree ztree : list) {
            if (t.getId().equals(ztree.getPId())) {
                return true;
            }
        }
        return false;
    }

    
    public static List getBuildTree(List list){
        List trees = new ArrayList<>();
        for(Ztree node:list){
            if(StringUtils.isEmpty(node.getPId())){
                trees.add(findChild(node,list));
            }
        }
        return trees;
    }

    //解决上级id不为空也能筛选出来
    public static List getBuildTreeNew(List list){
        List trees = getParents(list);
        for (Ztree node : trees){
            findChild(node,list);
        }
        return trees;
    }

    private static Ztree findChild(Ztree node, List list){
        for(Ztree n:list){
            if(node.getId().equals(n.getPId())){
                node.getChildren().add(findChild(n,list));
            }
        }
        return node;
    }

}

package pit.common.web.response;

import cn.hutool.core.collection.CollUtil;
import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

@Data
public class Ztree implements Serializable {

    private static final long serialVersionUID = 1L;

    
    private String id;

    
    private String pId;

    
    private String name;

    
    private String title;

    
    private String description;

    
    private String type;

    
    private Boolean checked = false;

    
    private Boolean open = false;

    
    private Boolean isOpen = true;

    
    private Boolean nocheck = false;

    
    private Boolean isEnable = true;

    
    private Integer sort;

    
    private List Children = new ArrayList<>();
    
    private Integer count;

    
    private Boolean isDisabled = true;

}

	public static void main(String[] args) {
        List dataList = new ArrayList<>();
        //调用 返回树结构
        ZtreeUtils.getBuildTreeNew(initZtree(dataList));
    }

    public List initZtree(List list) {
        List ztreeList = new ArrayList<>();
        for (PitDdsDrawingCatalogEntity pitDdsDrawingCatalog : list) {
            Ztree ztree = new Ztree();
            ztree.setId(pitDdsDrawingCatalog.getDrawingCatalogId());
            ztree.setPId(pitDdsDrawingCatalog.getUpDrawingCatalogId());
            ztree.setName(pitDdsDrawingCatalog.getDrawingCatalogName());
            ztreeList.add(ztree);
        }
        return ztreeList;
    }