From 8db4f0c8f7044c49c48d991dd9e860c857aa98a8 Mon Sep 17 00:00:00 2001
From: Rootrl <danhoo@163.com>
Date: Thu, 8 Dec 2022 14:45:53 +0800
Subject: [PATCH] =?UTF-8?q?=E9=80=9A=E7=94=A8=E6=A0=91=E5=BD=A2=E8=8F=9C?=
 =?UTF-8?q?=E5=8D=95=E7=94=9F=E6=88=90=E5=B7=A5=E5=85=B7=E7=B1=BB?=
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---
 .../ruoyi/common/core/utils/trees/Tree.java   | 136 ++++++++++++++++++
 .../common/core/utils/trees/TreeNode.java     |  30 ++++
 2 files changed, 166 insertions(+)
 create mode 100755 ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/Tree.java
 create mode 100755 ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/TreeNode.java

diff --git a/ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/Tree.java b/ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/Tree.java
new file mode 100755
index 00000000..514a5122
--- /dev/null
+++ b/ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/Tree.java
@@ -0,0 +1,136 @@
+package com.ruoyi.common.core.utils.trees;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 树形菜单生成工具类
+ * @param <T>
+ */
+public class Tree <T>{
+
+    /**
+     * 扁平化的树形结构
+     */
+    protected List<TreeNode> flatTrees = new ArrayList<>();
+
+    /**
+     * 所有根节点
+     */
+    public List<TreeNode> rootTrees = new ArrayList<>();
+
+    /**
+     * Id key标识
+     */
+    protected String idFlag;
+
+    /**
+     * pid key标识
+     */
+    protected String pidFlag;
+
+    /**
+     * name key标识
+     */
+    protected String nameFlag;
+
+    /**
+     * 使用默认属性名
+     */
+    public Tree() {
+        this("MenuId", "ParentId", "MenuName");
+    }
+
+    /**
+     * 自定义修改属性名
+     * @param idFlag
+     * @param pidFlag
+     * @param nameFlag
+     */
+    public Tree(String idFlag, String pidFlag, String nameFlag) {
+        this.idFlag = idFlag;
+        this.pidFlag = pidFlag;
+        this.nameFlag = nameFlag;
+    }
+
+    /**
+     * 生成树形菜单
+     * @return
+     */
+    public List<TreeNode> generateTrees(List<T> anyTrees) throws Exception {
+
+        // 处理给定的树形结构
+        screenTrees(anyTrees);
+
+        // 找到父节点下面所有子节点 - 递归
+        generateRecursionTrees();
+
+        return rootTrees;
+    }
+
+    /**
+     * 从任意扁平树结构中生成待处理的扁平化的树形结构 以及 根节点
+     * @param anyTrees
+     * @return
+     */
+    protected void screenTrees(List<T> anyTrees) throws Exception {
+        for (T anyTree: anyTrees) {
+            TreeNode treeNode = new TreeNode();
+
+            try {
+                treeNode.id = (Long) anyTree.getClass().getMethod("get" + idFlag).invoke(anyTree);
+                treeNode.pid = (Long) anyTree.getClass().getMethod("get" + pidFlag).invoke(anyTree);
+                treeNode.label = (String) anyTree.getClass().getMethod("get" + nameFlag).invoke(anyTree);
+            } catch (Exception e) {
+                throw new Exception(e.getMessage());
+            }
+
+            // 提取root节点和子节点
+            if (treeNode.pid == 0L) {
+                this.rootTrees.add(treeNode);
+            } else {
+                this.flatTrees.add(treeNode);
+            }
+        }
+    }
+
+    /**
+     * 使用递归方式生成树形结构
+     */
+    protected void generateRecursionTrees() {
+        for (TreeNode rootTreeNode : rootTrees) {
+            recursionFunction(rootTreeNode);
+        }
+    }
+
+    /**
+     * 递归函数
+     * @param rootTreeNode
+     */
+    protected void recursionFunction(TreeNode rootTreeNode) {
+
+        List<TreeNode> usedTreeNode = new ArrayList<>();
+
+        for(TreeNode treeNode : flatTrees) {
+            if (treeNode.pid == rootTreeNode.id) {
+                rootTreeNode.children.add(treeNode);
+                // 标记使用过的node
+                usedTreeNode.add(treeNode);
+            }
+        }
+
+        // 删除标记的node
+        flatTrees.removeAll(usedTreeNode);
+
+        // 终止条件
+        if (usedTreeNode.size() == 0) {
+            return;
+        }
+
+        // 递归
+        for (TreeNode treeNode: usedTreeNode) {
+            recursionFunction(treeNode);
+        }
+    }
+
+}
diff --git a/ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/TreeNode.java b/ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/TreeNode.java
new file mode 100755
index 00000000..6ddde44d
--- /dev/null
+++ b/ruoyi-common/ruoyi-common-core/src/main/java/com/ruoyi/common/core/utils/trees/TreeNode.java
@@ -0,0 +1,30 @@
+package com.ruoyi.common.core.utils.trees;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Tree node
+ */
+public class TreeNode {
+
+    /**
+     * ID
+     */
+    public Long id;
+
+    /**
+     * parentId
+     */
+    public Long pid;
+
+    /**
+     * Node name
+     */
+    public String label;
+
+    /**
+     * Child nodes
+     */
+    public List<TreeNode> children = new ArrayList<>();
+}
\ No newline at end of file