Pre Merge pull request !296 from danhoo/master

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);
+        }
+    }
+
+}

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<>();
+}