Fly365 / tree

将数据库中的父子结构（id和parentId）的数据转成树状结构。方便的查询树中的节点，某个几节点的所有父级等

父子结构转树状结构的工具

将数据库中的父子结构（id和parentId）的数据转成树状结构 方便的查询树中的节点，某个几节点的所有父级等

使用方法

1. 添加maven依赖

   <dependency>
       <groupId>io.github.guoyixing</groupId>
       <artifactId>tree</artifactId>
       <version>1.0</version>
   </dependency>

2. 将需要的树结构化的类添加TreeI接口

   public class Menu implements TreeI {
       private String id;
       private String parentId;
       private String name;
   
       /* 省略getter、setter */
   
       @Override
       public String getTreeId() {
           return getId();
       }
   
       @Override
       public String getTreeParentId() {
           return getParentId();
       }
   
       @Override
       public String getTreeName() {
           return getName();
       }
   }

3. 生成树结构

    public class Test {
        public static void main(String[] args) {
            List<Menu> menuList = new ArrayList<>();
    
            menuList.add(new Menu("1", "0", "一级菜单1"));
            menuList.add(new Menu("2","0","一级菜单2"));
            menuList.add(new Menu("1-1","1","二级菜单1"));
            menuList.add(new Menu("1-2","2","二级菜单2"));
            menuList.add(new Menu("1-1-1","1-1","三级级菜单1"));
            menuList.add(new Menu("1-1-2","1-1","三级级菜单2"));
            
            //树结构
            List<Tree<Menu>> trees = new TreeUtils<>(menuList).buildForest();
        }
    }

4. 效果

   [
       {
           "id": "1",
           "parentId": "0",
           "name": "一级菜单1"
       },
       {
           "id": "2",
           "parentId": "0",
           "name": "一级菜单2"
       },
       {
           "id": "1-1",
           "parentId": "0",
           "name": "二级菜单1"
       },
       {
           "id": "1-2",
           "parentId": "0",
           "name": "二级菜单2"
       },
       {
           "id": "1-1-1",
           "parentId": "0",
           "name": "三级级菜单1"
       },
       {
           "id": "1-2-2",
           "parentId": "0",
           "name": "三级级菜单2"
       }
   ]

   转成

   [
       {
           "id": "1",
           "name": "一级菜单1",
           "nodeData": {
               "id": "1",
               "parentId": "0",
               "name": "一级菜单1"
           },
           "total": 1,
           "parent": [],
           "children": [
               {
                   "id": "1-1",
                   "name": "二级菜单1",
                   "nodeData": {
                       "id": "1-1",
                       "parentId": "1",
                       "name": "二级菜单1"
                   },
                   "total": 2,
                   "parent": [
                       {
                           "id": "1",
                           "parentId": "0",
                           "name": "一级菜单1"
                       }
                   ],
                   "children": [
                       {
                           "id": "1-1-1",
                           "name": "三级级菜单1",
                           "nodeData": {
                               "id": "1-1-1",
                               "parentId": "1-1",
                               "name": "三级级菜单1"
                           },
                           "total": 0,
                           "parent": [
                               {
                                   "id": "1",
                                   "parentId": "0",
                                   "name": "一级菜单1"
                               },
                               {
                                   "id": "1-1",
                                   "parentId": "1",
                                   "name": "二级菜单1"
                               }
                           ],
                           "children": [],
                           "level": 3
                       },
                       {
                           "id": "1-1-2",
                           "name": "三级级菜单2",
                           "nodeData": {
                               "id": "1-1-2",
                               "parentId": "1-1",
                               "name": "三级级菜单2"
                           },
                           "total": 0,
                           "parent": [
                               {
                                   "id": "1",
                                   "parentId": "0",
                                   "name": "一级菜单1"
                               },
                               {
                                   "id": "1-1",
                                   "parentId": "1",
                                   "name": "二级菜单1"
                               }
                           ],
                           "children": [],
                           "level": 3
                       }
                   ],
                   "level": 2
               }
           ],
           "level": 1
       },
       {
           "id": "2",
           "name": "一级菜单2",
           "nodeData": {
               "id": "2",
               "parentId": "0",
               "name": "一级菜单2"
           },
           "total": 1,
           "parent": [],
           "children": [
               {
                   "id": "1-2",
                   "name": "二级菜单2",
                   "nodeData": {
                       "id": "1-2",
                       "parentId": "2",
                       "name": "二级菜单2"
                   },
                   "total": 0,
                   "parent": [
                       {
                           "id": "2",
                           "parentId": "0",
                           "name": "一级菜单2"
                       }
                   ],
                   "children": [],
                   "level": 2
               }
           ],
           "level": 1
       }
   ]

提供的一些工具方法

1、根据id查找树中的节点

List<Tree<Menu>> trees = new TreeUtils<>(menuList).buildForest();

Tree<Menu> node = TreeUtils.getNode(trees, "1");

2、获取节点中的数据

List<Tree<Menu>> trees = new TreeUtils<>(menuList).buildForest();

Tree<Menu> node = TreeUtils.getNode(trees, "1");

Menu nodeData = node.getNodeData();

3、获取某个节点的所有父节点

List<Tree<Menu>> trees = new TreeUtils<>(menuList).buildForest();

Tree<Menu> node = TreeUtils.getNode(trees, "1");

List<Menu> parent = node.getParent();

4、获取某个节点的子树

List<Tree<Menu>> trees = new TreeUtils<>(menuList).buildForest();

Tree<Menu> node = TreeUtils.getNode(trees, "1");

List<Tree<Menu>> children = node.getChildren();

5、获取所有的叶子节点

List<Tree<Menu>> trees = new TreeUtils<>(menuList).buildForest();

List<Tree<Menu>> allLeaf = TreeUtils.getAllLeaf(trees);

6、将树结构转成列表

List<Tree<Menu>> trees = new TreeUtils<>(menuList).buildForest();

List<Tree<Menu>> treeList = TreeUtils.toList(trees);

7、生成树的时候进行排序

List<Tree<Menu>> trees = new TreeUtils<>(menuList)
        .setSort(Comparator.comparing(t1 -> t1.getNodeData().getSortOrder()))
        .buildForest();