java樹形結構數據遍歷全部分支

如今有一個樹形結構的元素集合map list，要求遍歷該樹的全部分支

代碼以下：

package com.inslink.controller.element;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.baomidou.mybatisplus.service.IService;
import com.inslink.controller.GenericController;
import com.inslink.model.element.core.Element;
import com.inslink.service.element.ElementService;

public class RobotLogicTreeController  {

    
    @Autowired
    private ElementService elementService;
    
    private static boolean flag = true;
    
    private static List<List<Map<String, Object>>> excellist = new ArrayList<List<Map<String,Object>>>();
    
    private static Map<String, Object> parentMap = new HashMap<String, Object>();
    
    private static List<Map<String,Object>> mlist = new ArrayList<Map<String,Object>>();
    
    //遍歷全部分支
    public static List<Map<String,Object>> getSonMap(Map<String,Object> parentMap1,List<Map<String,Object>> treeElements,List<Map<String,Object>> list) {
            
        if (parentMap1.get("parent")==null) {
            list.add(parentMap1);
        }
            
            for (int i=0;i<treeElements.size();i++) {

                Map<String,Object> map = treeElements.get(i);
                if (map.get("parent")!=null && parentMap1.get("id").toString().equals(map.get("parent").toString())) {
                    flag = true;
                    
                    list.add(map);
                    getSonMap(map,treeElements,list); 
                }
                //不存在子節點
                else {
                    flag = false;
                    continue;
                }
                
                if (!flag) {                     
                    
                    if (list.size()>1) {
                        
                        //判斷新增的list中的在樹中是否存在子節點
                        boolean exist = false;                       
                        for (Map<String,Object> s : mlist) {
                            
                            System.out.println(s.get("parent"));
                            if (s.get("parent")!=null && s.get("parent").toString().equals(map.get("id").toString())) {
                                exist = true;
                                break;
                            }                            
                        }
                        if (!exist) {
                            excellist.add(list);
                        }
                        
                    }
                    //刪除此分支上全部只有一個子節點的節點或末支節點
                    treeElements.remove(map);
                    
                    list = new ArrayList<>();
                    getSonMap(parentMap,treeElements,list);                    
                    break;
                }
                
            }
            return list;
        
    }
    
    
    
    
    @Override
    protected IService<Element> getService() {
        // TODO Auto-generated method stub
        return null;
    }

    public static void main(String[] args) {
        Map<String,Object> map1 = new HashMap<String,Object>();
        map1.put("name", "乳腺");
        map1.put("level", "0");
        map1.put("id", "1");
        map1.put("parent", null);
        
        Map<String,Object> map2 = new HashMap<String,Object>();
        
        map2.put("name", "乳腺1");
        map2.put("level", "1");
        map2.put("id", "2");
        map2.put("parent", "1");
        
        Map<String,Object> map3 = new HashMap<String,Object>();
        
        map3.put("name", "乳腺2-1");
        map3.put("level", "2");
        map3.put("id", "3");
        map3.put("parent", "2");
        
        
        Map<String,Object> map4 = new HashMap<String,Object>();
        
        map4.put("name", "乳腺2-2");
        map4.put("level", "2");
        map4.put("id", "4");
        map4.put("parent", "2");
        
        
        Map<String,Object> map5 = new HashMap<String,Object>();
        
        map5.put("name", "乳腺2-3");
        map5.put("level", "2");
        map5.put("id", "5");
        map5.put("parent", "2");
        
        Map<String,Object> map6 = new HashMap<String,Object>();
        
        map6.put("name", "乳腺3-1");
        map6.put("level", "3");
        map6.put("id", "6");
        map6.put("parent", "3");
        
        Map<String,Object> map8 = new HashMap<String,Object>();
        
        map8.put("name", "乳腺3-8");
        map8.put("level", "3");
        map8.put("id", "8");
        map8.put("parent", "3");
        
        
        Map<String,Object> map7 = new HashMap<String,Object>();
        
        map7.put("name", "乳腺3-2");
        map7.put("level", "3");
        map7.put("id", "7");
        map7.put("parent", "5");
        
        List<Map<String,Object>> treeElements = new ArrayList<Map<String,Object>>();
        treeElements.add(map1);
        treeElements.add(map2);
        treeElements.add(map3);
        treeElements.add(map4);
        treeElements.add(map5);
        treeElements.add(map6);
        treeElements.add(map7);
        treeElements.add(map8);

//        Map<String,Object> treeMap = new HashMap<String,Object>();
//        map = sortTreeMap(map1, treeElements,treeMap);
        
        mlist  =   new  ArrayList<Map<String,Object>>(); 
        
        mlist = new ArrayList<Map<String,Object>>((Collection<? extends Map<String, Object>>) Arrays.asList(new Map[treeElements.size()]));  

        Collections.copy(mlist, treeElements);
        
        
        parentMap = map1;
        
        List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();
        
        list = getSonMap(parentMap, treeElements,list);
        

        for ( List<Map<String, Object>> slist : excellist) {
            System.out.println("=====");
            for (Map<String,Object> smap : slist) {
                System.out.println(smap.get("id"));
            }
        }
        
    }
    
}