add method for Tree

CHANGELOG.md

@@ -10,6 +10,7 @@
 * 【http   】     增加HttpResource（issue#1943@Github）
 * 【http   】     增加BytesBody、FormUrlEncodedBody
 * 【cron   】     TaskTable.remove增加返回值（issue#I4HX3B@Gitee）
+* 【core   】     Tree增加filter、filterNew、cloneTree、hasChild方法（issue#I4HFC6@Gitee）
 ### 🐞Bug修复
 * 【core   】     修复FileResource构造fileName参数无效问题（issue#1942@Github）
 

hutool-core/src/main/java/cn/hutool/core/lang/tree/Tree.java

@@ -2,6 +2,7 @@ package cn.hutool.core.lang.tree;
 
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.lang.Assert;
+import cn.hutool.core.lang.Filter;
 import cn.hutool.core.util.ArrayUtil;
 import cn.hutool.core.util.CharUtil;
 import cn.hutool.core.util.ObjectUtil;
@@ -21,7 +22,7 @@ import java.util.function.Consumer;
  * @author liangbaikai
  * @since 5.2.1
  */
-	public class Tree<T> extends LinkedHashMap<String, Object> implements Node<T> {
+public class Tree<T> extends LinkedHashMap<String, Object> implements Node<T> {
 	private static final long serialVersionUID = 1L;
 
 	private final TreeNodeConfig treeNodeConfig;
@@ -175,6 +176,16 @@ import java.util.function.Consumer;
 		return (List<Tree<T>>) this.get(treeNodeConfig.getChildrenKey());
 	}
 
+	/**
+	 * 是否有子节点，无子节点则此为叶子节点
+	 *
+	 * @return 是否有子节点
+	 * @since 5.7.17
+	 */
+	public boolean hasChild() {
+		return CollUtil.isNotEmpty(getChildren());
+	}
+
 	/**
 	 * 递归树并处理子树下的节点：
 	 *
@@ -184,18 +195,67 @@ import java.util.function.Consumer;
 	public void walk(Consumer<Tree<T>> consumer) {
 		consumer.accept(this);
 		final List<Tree<T>> children = getChildren();
-		if(CollUtil.isNotEmpty(children)){
+		if (CollUtil.isNotEmpty(children)) {
-			children.forEach((tree)-> tree.walk(consumer));
+			children.forEach((tree) -> tree.walk(consumer));
 		}
 	}
 
+	/**
+	 * 递归过滤并生成新的树<br>
+	 * 通过{@link Filter}指定的过滤规则，本节点或子节点满足过滤条件，则保留当前节点，否则抛弃节点及其子节点
+	 *
+	 * @param filter 节点过滤规则函数，只需处理本级节点本身即可
+	 * @return 过滤后的节点，{@code null} 表示不满足过滤要求，丢弃之
+	 * @see #filter(Filter)
+	 * @since 5.7.17
+	 */
+	public Tree<T> filterNew(Filter<Tree<T>> filter) {
+		return cloneTree().filter(filter);
+	}
+
+	/**
+	 * 递归过滤当前树，注意此方法会修改当前树<br>
+	 * 通过{@link Filter}指定的过滤规则，本节点或子节点满足过滤条件，则保留当前节点，否则抛弃节点及其子节点
+	 *
+	 * @param filter 节点过滤规则函数，只需处理本级节点本身即可
+	 * @return 过滤后的节点，{@code null} 表示不满足过滤要求，丢弃之
+	 * @see #filterNew(Filter)
+	 * @since 5.7.17
+	 */
+	public Tree<T> filter(Filter<Tree<T>> filter) {
+		final List<Tree<T>> children = getChildren();
+		if (CollUtil.isNotEmpty(children)) {
+			// 递归过滤子节点
+			final List<Tree<T>> filteredChildren = new ArrayList<>(children.size());
+			Tree<T> filteredChild;
+			for (Tree<T> child : children) {
+				filteredChild = child.filter(filter);
+				if (null != filteredChild) {
+					filteredChildren.add(filteredChild);
+				}
+			}
+			if(CollUtil.isNotEmpty(filteredChildren)){
+				// 子节点有符合过滤条件的节点，则本节点保留
+				return this.setChildren(filteredChildren);
+			} else {
+				this.setChildren(null);
+			}
+		}
+
+		// 子节点都不符合过滤条件，检查本节点
+		return filter.accept(this) ? this : null;
+	}
+
 	/**
 	 * 设置子节点，设置后会覆盖所有原有子节点
 	 *
-	 * @param children 子节点列表
+	 * @param children 子节点列表，如果为{@code null}表示移除子节点
 	 * @return this
 	 */
 	public Tree<T> setChildren(List<Tree<T>> children) {
+		if(null == children){
+			this.remove(treeNodeConfig.getChildrenKey());
+		}
 		this.put(treeNodeConfig.getChildrenKey(), children);
 		return this;
 	}
@@ -241,6 +301,34 @@ import java.util.function.Consumer;
 		return stringWriter.toString();
 	}
 
+	/**
+	 * 递归克隆当前节点（即克隆整个树，保留字段值）<br>
+	 * 注意，此方法只会克隆节点，节点属性如果是引用类型，不会克隆
+	 *
+	 * @return 新的节点
+	 * @since 5.7.17
+	 */
+	public Tree<T> cloneTree() {
+		final Tree<T> result = ObjectUtil.clone(this);
+		result.setChildren(cloneChildren());
+		return result;
+	}
+
+	/**
+	 * 递归复制子节点
+	 *
+	 * @return 新的子节点列表
+	 */
+	private List<Tree<T>> cloneChildren() {
+		final List<Tree<T>> children = getChildren();
+		if (null == children) {
+			return null;
+		}
+		final List<Tree<T>> newChildren = new ArrayList<>(children.size());
+		children.forEach((t) -> newChildren.add(t.cloneTree()));
+		return newChildren;
+	}
+
 	/**
 	 * 打印
 	 *

hutool-core/src/test/java/cn/hutool/core/lang/tree/TreeTest.java

@@ -76,4 +76,48 @@ public class TreeTest {
 
 		Assert .assertEquals(7, ids.size());
 	}
+
+	@Test
+	public void cloneTreeTest(){
+		final Tree<String> tree = TreeUtil.buildSingle(nodeList, "0");
+		final Tree<String> cloneTree = tree.cloneTree();
+
+		List<String> ids = new ArrayList<>();
+		cloneTree.walk((tr)-> ids.add(tr.getId()));
+
+		Assert .assertEquals(7, ids.size());
+	}
+
+	@Test
+	public void filterTest(){
+		// 经过过滤，丢掉"用户添加"节点
+		final Tree<String> tree = TreeUtil.buildSingle(nodeList, "0");
+		tree.filter((t)->{
+			final CharSequence name = t.getName();
+			return null != name && name.toString().contains("管理");
+		});
+
+		List<String> ids = new ArrayList<>();
+		tree.walk((tr)-> ids.add(tr.getId()));
+		Assert .assertEquals(6, ids.size());
+	}
+
+	@Test
+	public void filterNewTest(){
+		final Tree<String> tree = TreeUtil.buildSingle(nodeList, "0");
+
+		// 经过过滤，生成新的树
+		Tree<String> newTree = tree.filterNew((t)->{
+			final CharSequence name = t.getName();
+			return null != name && name.toString().contains("管理");
+		});
+
+		List<String> ids = new ArrayList<>();
+		newTree.walk((tr)-> ids.add(tr.getId()));
+		Assert .assertEquals(6, ids.size());
+
+		List<String> ids2 = new ArrayList<>();
+		tree.walk((tr)-> ids2.add(tr.getId()));
+		Assert .assertEquals(7, ids2.size());
+	}
 }

hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimingWheel.java

@@ -68,7 +68,6 @@ public class TimingWheel {
 	 * @param consumer    任务处理器
 	 */
 	public TimingWheel(long tickMs, int wheelSize, long currentTime, Consumer<TimerTaskList> consumer) {
-		this.currentTime = currentTime;
 		this.tickMs = tickMs;
 		this.wheelSize = wheelSize;
 		this.interval = tickMs * wheelSize;