前端需要实现设计如图：

后端设计返回的数据类型如下（数据量太大，省略部分数据）：

1 {"code":0,"msg":null,"data":[{"sortName":"未知","sortCode":"-","parentCid":"","childrens":[]},
{"sortName":"食品\r\n部","sortCode":"1","parentCid":"","childrens":
[{"sortName":"烟酒饮料","sortCode":"100","parentCid":"1","childrens":
[{"sortName":"软性饮料","sortCode":"1000","parentCid":"100","childrens":
[{"sortName":"碳酸饮料","sortCode":"10000","parentCid":"1000","childrens":
[{"sortName":"可乐","sortCode":"100000","parentCid":"10000","childrens":[]},
{"sortName":"加味汽水","sortCode":"100001","parentCid":"10000","childrens":[]},
{"sortName":"其它汽水","sortCode":"100002","parentCid":"10000","childrens":[]}]},
{"sortName":"蔬果汁","sortCode":"10001","parentCid":"1000","childrens":
[{"sortName":"蔬菜汁","sortCode":"100010","parentCid":"10001","childrens":[]},
{"sortName":"橙汁","sortCode":"100011","parentCid":"10001","childrens":[]},
{"sortName":"苹果汁","sortCode":"100012","parentCid":"10001","childrens":[]},
{"sortName":"浓缩果汁","sortCode":"100013","parentCid":"10001","childrens":[]},
{"sortName":"其它果汁","sortCode":"100014","parentCid":"10001","childrens":[]},
{"sortName":"桃汁","sortCode":"100015","parentCid":"10001","childrens":[]},
{"sortName":"葡萄汁","sortCode":"100016","parentCid":"10001","childrens":[]},
{"sortName":"混合果汁","sortCode":"100017","parentCid":"10001","childrens":[]}]},
{"sortName":"机能性饮料","sortCode":"10002","parentCid":"1000","childrens":
[{"sortName":"咖啡饮料","sortCode":"100020","parentCid":"10002","childrens":
[]},{"sortName":"功能饮料","sortCode":"100021","parentCid":"10002","childrens":
[]}]},{"sortName":"茶饮料","sortCode":"10003","parentCid":"1000","childrens":
[{"sortName":"奶茶","sortCode":"100030","parentCid":"10003","childrens":
[]},{"sortName":"加味茶","sortCode":"100031","parentCid":"10003","childrens":
[]},{"sortName":"功能茶","sortCode":"100032","parentCid":"10003","childrens":
[]}]},{"sortName":"水","sortCode":"10004","parentCid":"1000","childrens":
[{"sortName":"纯水","sortCode":"100040","parentCid":"10004","childrens":
[]},{"sortName":"矿泉水","sortCode":"100041","parentCid":"10004","childrens":
[]},{"sortName":"含碳酸水","sortCode":"100042","parentCid":"10004","childrens":
[]},{"sortName":"其它类水","sortCode":"100043","parentCid":"10004","childrens":[]}]}

 这边后端数据类别是共有5个节点，设计实体如下：

public class SortNode {

  /**
   * 类被名称
   */
  private String sortName;

  /**
   * 类别代码
   */
  private String sortCode;

  /**
   * 父节点
   */
  private String parentCid;

  /**
   * 所有子节点
   */
  private List<SortNode> childrens;
｝

利用递归，实现返回树状数据逻辑代码如下：

 public List<SortNode> querySortNode(String storeCode) throws Exception {

　　//从数据库获取配置字段并排序
    String sortValue = applicationOptionService.getOptionValue(
        storeCode, ApplicationOptionService.RUMBA_PREFS_MODULE_NO, LocalPrefParam.BASIC_INFORMATION_GOODS_SORT);
    List<String> sortLength = Arrays.asList(verifySorts(sortValue, storeCode));
    Collections.sort(sortLength);

　　//查询出所有的数据，给父节点赋值
    List<SortNode> sortNodes = new ArrayList<>();
    List<Sort> sorts = sortDao.getSorts();
    sorts.forEach(sort -> {
      SortNode sortNode = new SortNode(sort.getName(), sort.getCode());
      String code = sortNode.getSortCode();
      int reduce;
      int nextSortLength = getLastSortLength(sortLength, code.length());
      if (nextSortLength == 0) {
        reduce = 1;
      } else {
        reduce = code.length() - nextSortLength;
      }
      String parentCid = code.substring(0, code.length() - reduce);
      sortNode.setParentCid(parentCid);
      sortNodes.add(sortNode);
    });

　　// 给子节点塞值
    List<SortNode> collect = sortNodes.stream()
        .filter(o -> o.getParentCid().equals(""))
        .peek(o -> o.setChildrens(getChildSortNode(o, sortNodes)))
        .collect(Collectors.toList());
    return collect;
  }

  /**
   * 递归赋值子节点
   */
  private List<SortNode> getChildSortNode(SortNode sortNode, List<SortNode> sortNodes) {
    List<SortNode> collect = sortNodes.stream().filter(o -> o.getParentCid().equals(sortNode.getSortCode()))
        .peek(o -> o.setChildrens(getChildSortNode(o, sortNodes)))
        .collect(Collectors.toList());
    return collect;
  }