From c09249dfe425db29358451eecbcb0f37c2347f2a Mon Sep 17 00:00:00 2001
From: GPU is all you need <2778335106@qq.com>
Date: Thu, 19 May 2022 20:15:07 +0800
Subject: [PATCH] =?UTF-8?q?=E5=B0=81=E8=A3=85=E7=9A=84=E6=A0=91=E5=BD=A2?=
 =?UTF-8?q?=E7=BB=84=E4=BB=B6=E5=B7=A5=E5=85=B7=E7=B1=BB?=
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---
 .../award/common/util/treeUtils/TreeNode.java | 34 +++++++++
 .../common/util/treeUtils/TreeUtils.java      | 70 +++++++++++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeNode.java
 create mode 100644 awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeUtils.java

diff --git a/awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeNode.java b/awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeNode.java
new file mode 100644
index 0000000..cba299e
--- /dev/null
+++ b/awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeNode.java
@@ -0,0 +1,34 @@
+package edu.ncst.award.common.util.treeUtils;
+
+
+import java.util.List;
+
+public class TreeNode {
+    private Integer id;
+    private Integer parentId;
+    private List<TreeNode> Children;
+
+    public List<TreeNode> getChildren() {
+        return Children;
+    }
+
+    public void setChildren(List<TreeNode> children) {
+        Children = children;
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public Integer getParentId() {
+        return parentId;
+    }
+
+    public void setParentId(Integer parentId) {
+        this.parentId = parentId;
+    }
+}
diff --git a/awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeUtils.java b/awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeUtils.java
new file mode 100644
index 0000000..7164187
--- /dev/null
+++ b/awardBE/src/main/java/edu/ncst/award/common/util/treeUtils/TreeUtils.java
@@ -0,0 +1,70 @@
+package edu.ncst.award.common.util.treeUtils;
+
+import cn.hutool.core.util.ReflectUtil;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * 菜单工具类
+ *
+ * @author Gpu is all you need
+ * @date 2022/05/07
+ */
+public class TreeUtils {
+
+    public interface Convert<T, TreeNode> {
+        void convert(T dataObject, TreeNode treeNode);
+    }
+
+
+    /**
+     * 构建树结构
+     *
+     * @param parentNodeId 根节点id
+     * @param treeNodes    所有节点的列表
+     * @param convert      转换接口实现 treeNode 转换 目标节点 (把目标节点的属性复制给treeNode)
+     * @param <T>          目标节点类型
+     * @return 树结构 目标节点类型
+     */
+    static public <T, E extends TreeNode> List<E>
+    build(Integer parentNodeId, List<T> treeNodes, Class<E> dataObjectClass, Convert<T, E> convert) {
+
+        // 防止对原始数据做修改
+        List<E> result = new ArrayList<>();
+
+        for (T dataObject : treeNodes) {
+            E treeNode = ReflectUtil.newInstance(dataObjectClass);
+            convert.convert(dataObject, treeNode);
+            result.add(treeNode);
+        }
+
+        for (E menu : result) {
+            if (menu.getParentId().equals(parentNodeId)) {
+                innerBuild(menu, result);
+            }
+        }
+        // 只要树结构,去掉多余的那种散落其他地方但是已经挂在树上的
+        return result.stream().filter(treeNode -> treeNode.getParentId().equals(parentNodeId)).collect(Collectors.toList());
+    }
+
+    /**
+     * 递归内部构建
+     *
+     * @param parentTreeNode 初始父节点 / 上一次调用的节点作为父节点
+     * @param treeNodes      所有节点的列表
+     */
+    static private void innerBuild(TreeNode parentTreeNode, List<? extends TreeNode> treeNodes) {
+        for (TreeNode treeNode : treeNodes) {
+            if (treeNode.getParentId().equals(parentTreeNode.getId())) {
+                if (parentTreeNode.getChildren() == null) {
+                    parentTreeNode.setChildren(new ArrayList<>());
+                }
+                innerBuild(treeNode, treeNodes);
+                parentTreeNode.getChildren().add(treeNode);
+            }
+        }
+    }
+}
+