java树形结构组装工具类

import java.util.ArrayList;
import java.util.List;

import lombok.Data;

@Data
public class BillTreeDto {
  /**
   * 当前节点id
   */
  private String id;

  /**
   * 父节点id
   */
  private String parentId;

  /**
   * 名称
   */
  private String name;

  private List<BillTreeDto> childsList = new ArrayList<BillTreeDto>();
}

package com.ufgov.pvdf.util;

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

import com.ufgov.pvdf.billparse.dto.BillTreeDto;

public class TreeUtil {

  public List<BillTreeDto> getTreeData(List<BillTreeDto> list) {
    List<BillTreeDto> returnList = new ArrayList<BillTreeDto>();
    for (Iterator<BillTreeDto> iterator = list.iterator(); iterator.hasNext();) {
      BillTreeDto res = iterator.next();
      //判断是否为第一个节点:parentId为空
      if (StringUtil.isEmptyString(res.getParentId())) {
        recursionFn(list, res);
        returnList.add(res);
      }
    }
    return returnList;
  }

  /**
   * 递归寻找子节点
   * @Title: recursionFn     
   * @Description: 递归寻找子节点    
   * @param beans 所有节点
   * @param current 当前节点    
   */
  private void recursionFn(List<BillTreeDto> beans, BillTreeDto current) {
    List<BillTreeDto> childsList = getChildList(beans, current);
    current.setChildsList(childsList);
    for (BillTreeDto nextChild : childsList) {
      recursionFn(beans, nextChild);
    }
  }

  /**
   * 获得指定节点下的所有子节点
   * @Title: getChildList     
   * @Description: 获得指定节点下的所有子节点    
   * @param beans 所有节点集合
   * @param current 当前节点
   * @return       
   */
  private List<BillTreeDto> getChildList(List<BillTreeDto> beans, BillTreeDto current) {
    List<BillTreeDto> childsList = new ArrayList<BillTreeDto>();
    Iterator<BillTreeDto> it = beans.iterator();
    while (it.hasNext()) {
      BillTreeDto child = it.next();
      if (current.getId().equals(child.getParentId())) {
        childsList.add(child);
      }
    }
    return childsList;
  }

}