修复SystemTimer无法结束进程问题

hutool-cron/src/main/java/org/dromara/hutool/cron/timingwheel/SystemTimer.java

@@ -43,6 +43,7 @@ public class SystemTimer {
 	 * 轮询delayQueue获取过期任务线程
 	 */
 	private ExecutorService bossThreadPool;
+	private volatile boolean isRunning;
 
 	/**
 	 * 构造
@@ -68,6 +69,7 @@ public class SystemTimer {
 	 */
 	public SystemTimer start() {
 		bossThreadPool = ThreadUtil.newSingleExecutor();
+		isRunning = true;
 		bossThreadPool.submit(() -> {
 			while (true) {
 				if(!advanceClock()){
@@ -82,6 +84,7 @@ public class SystemTimer {
 	 * 强制结束
 	 */
 	public void stop(){
+		this.isRunning = false;
 		this.bossThreadPool.shutdown();
 	}
 
@@ -103,6 +106,9 @@ public class SystemTimer {
 	 * @return 是否结束
 	 */
 	private boolean advanceClock() {
+		if(!isRunning){
+			return false;
+		}
 		try {
 			final TimerTaskList timerTaskList = poll();
 			if (null != timerTaskList) {

hutool-cron/src/test/java/org/dromara/hutool/cron/timingwheel/Issue3090Test.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2023 looly(loolly@aliyun.com)
+ * Hutool is licensed under Mulan PSL v2.
+ * You can use this software according to the terms and conditions of the Mulan PSL v2.
+ * You may obtain a copy of Mulan PSL v2 at:
+ *          http://license.coscl.org.cn/MulanPSL2
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PSL v2 for more details.
+ */
+
+package org.dromara.hutool.cron.timingwheel;
+
+public class Issue3090Test {
+	public static void main(String[] args) {
+		SystemTimer timer = new SystemTimer();
+		timer.setDelayQueueTimeout(1000);
+		timer.start();
+		timer.addTask(new TimerTask(() -> {
+			System.out.println(1);
+			System.out.println("任务已经完成");
+		}, 1000));
+
+		timer.stop();
+		System.out.println("线程池已经关闭");
+	}
+}