JAVA使用hutool工具实现查询树结构数据(省市区)

@PostMapping ( "/getTree" )

     public Object getTree() {

         // 查询数据

         List<LxhpArea> areaList = areaService.list();

         // 构建的整个树数据

         List<TreeNode<String>> treeNodeList = areaList.stream().map(area -> {

             // 扩展字段赋值，下面要取这里的值

             Map<String, Object> extraMap = new HashMap<>();

             extraMap.put( "domain" , area.getDomain());

             extraMap.put( "isOpen" , area.getIsOpen());

             extraMap.put( "bigArea" , area.getBigArea());

             // 单个树数据构建

             TreeNode<String> treeNode = new TreeNode<String>()

                     .setId(String.valueOf(area.getId())) // 主键

                     .setParentId(String.valueOf(area.getReid())) // 父节点ID

                     .setName(area.getName()) // 省份名称

                     .setWeight(area.getSortOrder()) //权重，排序

                     .setExtra(extraMap); // 扩展字段

             return treeNode;

         }).collect(Collectors.toList());

         // 配置

         TreeNodeConfig treeNodeConfig = new TreeNodeConfig();

         // 自定义属性名（修改默认名称）

         treeNodeConfig.setWeightKey( "sortOrder" );

         treeNodeConfig.setChildrenKey( "childrenNode" );

         // 最大递归深度

         treeNodeConfig.setDeep( 1 );

         //转换器

         List<Tree<String>> treeNodes = TreeUtil.build(treeNodeList, "1" , treeNodeConfig,

                 (treeNode, tree) -> {

                     // 给树节点赋值（还能set 父 或子节点树）

                     tree.setId(treeNode.getId());

                     tree.setParentId(treeNode.getParentId());

                     tree.setWeight(treeNode.getWeight());

                     tree.setName(treeNode.getName());

                     // 扩展属性值赋值

                     // treeNode.getExtra().getOrDefault("domain", null) 是获取上面Map放进去的值，没有就是 null

                     tree.putExtra( "domain" , treeNode.getExtra().getOrDefault( "domain" , null ));

                     tree.putExtra( "isOpen" , treeNode.getExtra().getOrDefault( "isOpen" , null ));

                     tree.putExtra( "bigArea" , treeNode.getExtra().getOrDefault( "bigArea" , null ));

                 });

         return JSONUtil.parse(treeNodes);

     }

CREATE TABLE `lxhp_area` (

   `id` smallint (5) unsigned NOT NULL AUTO_INCREMENT,

   `reid` smallint (5) unsigned NOT NULL DEFAULT '0' ,

   ` name ` varchar (120) NOT NULL DEFAULT '' ,

   `sort_order` smallint (5) unsigned NOT NULL DEFAULT '0' ,

   `is_open` tinyint(3) unsigned NOT NULL DEFAULT '0' ,

   `domain` varchar (10) NOT NULL ,

   `big_area` int (4) DEFAULT NULL ,

   PRIMARY KEY (`id`)

) ENGINE=MyISAM AUTO_INCREMENT=3433 DEFAULT CHARSET=utf8;