add event

hutool-core/src/main/java/org/dromara/hutool/core/lang/event/Event.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2024 Hutool Team and hutool.cn
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.dromara.hutool.core.lang.event;
+
+/**
+ * 事件接口，所有事件必须实现此接口
+ *
+ * @author Looly
+ */
+public interface Event{
+}

hutool-core/src/main/java/org/dromara/hutool/core/lang/event/EventPublisher.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2024 Hutool Team and hutool.cn
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.dromara.hutool.core.lang.event;
+
+/**
+ * 事件发布者接口，用于发布事件
+ *
+ * @author Looly
+ */
+public interface EventPublisher {
+
+	/**
+	 * 注册订阅者，订阅者将接收到所有发布者发布的事件
+	 *
+	 * @param subscriber 订阅者
+	 * @return this
+	 */
+	EventPublisher register(Subscriber subscriber);
+
+	/**
+	 * 发布事件，事件发布者将事件发布给所有订阅者
+	 *
+	 * @param event 事件对象
+	 */
+	void publish(Event event);
+}

hutool-core/src/main/java/org/dromara/hutool/core/lang/event/SimpleEventPublisher.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2024 Hutool Team and hutool.cn
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.dromara.hutool.core.lang.event;
+
+import org.dromara.hutool.core.lang.Assert;
+import org.dromara.hutool.core.lang.loader.LazyFunLoader;
+import org.dromara.hutool.core.lang.loader.Loader;
+import org.dromara.hutool.core.thread.ThreadUtil;
+import org.dromara.hutool.core.util.ObjUtil;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+
+/**
+ * 简单的事件发布者实现，基于{@link Subscriber}和{@link Event}实现
+ *
+ * @author looly
+ * @since 6.0.0
+ */
+public class SimpleEventPublisher implements EventPublisher {
+
+	/**
+	 * 创建一个默认的{@code SimpleEventPublisher}，默认线程池为{@link ThreadUtil#newExecutor()}
+	 *
+	 * @return {@code SimpleEventPublisher}
+	 */
+	public static SimpleEventPublisher of() {
+		return of(null);
+	}
+
+	/**
+	 * 创建一个默认的{@code SimpleEventPublisher}，默认线程池为{@link ThreadUtil#newExecutor()}
+	 *
+	 * @param subscribers 订阅者列表，也可以传入空列表后调用{@link #register(Subscriber)}添加
+	 * @return {@code SimpleEventPublisher}
+	 */
+	public static SimpleEventPublisher of(final List<Subscriber> subscribers) {
+		return new SimpleEventPublisher(subscribers, null);
+	}
+
+	private final List<Subscriber> subscribers;
+	private Loader<ExecutorService> executorServiceLoader;
+
+	/**
+	 * 构造
+	 *
+	 * @param subscribers           订阅者列表
+	 * @param executorServiceLoader 线程池加载器，用于异步执行，默认为{@link ThreadUtil#newExecutor()}
+	 */
+	public SimpleEventPublisher(final List<Subscriber> subscribers, final Loader<ExecutorService> executorServiceLoader) {
+		this.subscribers = ObjUtil.defaultIfNull(subscribers, ArrayList::new);
+		this.executorServiceLoader = ObjUtil.defaultIfNull(executorServiceLoader, LazyFunLoader.of(ThreadUtil::newExecutor));
+	}
+
+	/**
+	 * 设置自定义的{@link ExecutorService}线程池，默认为{@link ThreadUtil#newExecutor()}
+	 *
+	 * @param executorService {@link ExecutorService}，不能为空
+	 * @return this
+	 */
+	public SimpleEventPublisher setExecutorService(final ExecutorService executorService) {
+		this.executorServiceLoader = () -> Assert.notNull(executorService);
+		return this;
+	}
+
+	@Override
+	public EventPublisher register(final Subscriber subscriber) {
+		subscribers.add(subscriber);
+		Collections.sort(subscribers);
+		return this;
+	}
+
+	@Override
+	public void publish(final Event event) {
+		for (final Subscriber subscriber : subscribers) {
+			if (subscriber.async()) {
+				executorServiceLoader.get().submit(() -> subscriber.update(event));
+			} else {
+				subscriber.update(event);
+			}
+		}
+	}
+}

hutool-core/src/main/java/org/dromara/hutool/core/lang/event/SourceEvent.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2024 Hutool Team and hutool.cn
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.dromara.hutool.core.lang.event;
+
+import java.util.EventObject;
+
+/**
+ * 基于事件源的事件实现
+ *
+ * @author looly
+ * @since 6.0.0
+ */
+public class SourceEvent extends EventObject implements Event {
+	private static final long serialVersionUID = 1L;
+
+	/**
+	 * 构造
+	 *
+	 * @param source 事件源
+	 */
+	public SourceEvent(final Object source) {
+		super(source);
+	}
+}

hutool-core/src/main/java/org/dromara/hutool/core/lang/event/Subscriber.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2024 Hutool Team and hutool.cn
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.dromara.hutool.core.lang.event;
+
+import org.dromara.hutool.core.comparator.CompareUtil;
+
+import java.util.EventListener;
+
+/**
+ * 订阅者接口
+ *
+ * @author Looly
+ */
+public interface Subscriber extends EventListener, Comparable<Subscriber> {
+
+	/**
+	 * 当事件发生时的操作
+	 *
+	 * @param event 事件对象，根据不同事件，可选是否执行
+	 */
+	void update(Event event);
+
+	/**
+	 * 获取事件执行顺序，值越小越先执行
+	 *
+	 * @return 执行顺序
+	 */
+	default int order() {
+		return 1000;
+	}
+
+	@Override
+	default int compareTo(final Subscriber o) {
+		return CompareUtil.compare(this.order(), o.order());
+	}
+
+	/**
+	 * 是否异步执行，默认为false，同步执行
+	 *
+	 * @return 是否异步执行
+	 */
+	default boolean async() {
+		return false;
+	}
+}

hutool-core/src/main/java/org/dromara/hutool/core/lang/event/package-info.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2024 Hutool Team and hutool.cn
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * 发布订阅模式封装，发布/订阅是一种消息范式<br>
+ * 消息的发送者（EventPublisher）将事件或消息（Event）广播出去，订阅者（Subscriber）接收到消息后处理。<br>
+ * Hutool中的事件或消息（Event）是一个无方法接口，可以通过实现此接口灵活的定义不同消息类型。<br>
+ * 消息的发送者（EventPublisher）可以通过register方法注册订阅者，调用publish发布消息
+ *
+ * <pre>{@code
+ *           publish                /----->Subscriber
+ *   Event  -------- EventPublisher- ----->Subscriber
+ *                                  \----->Subscriber
+ * }</pre>
+ *
+ * @author Looly
+ */
+package org.dromara.hutool.core.lang.event;

hutool-core/src/test/java/org/dromara/hutool/core/lang/event/SimpleEventPublisherTest.java

@@ -0,0 +1,35 @@
+package org.dromara.hutool.core.lang.event;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class SimpleEventPublisherTest {
+
+	@Test
+	void registerTest() {
+		final SimpleEventPublisher publisher = SimpleEventPublisher.of();
+		publisher.register(event -> Assertions.assertEquals("test", ((TestEvent)event).getName()));
+
+		publisher.publish(new TestEvent("test"));
+	}
+
+	@Test
+	void sourceEventTest() {
+		final SimpleEventPublisher publisher = SimpleEventPublisher.of();
+		publisher.register(event -> Assertions.assertEquals("test", ((SourceEvent)event).getSource()));
+
+		publisher.publish(new SourceEvent("test"));
+	}
+
+	private static class TestEvent implements Event {
+		private final String name;
+
+		public TestEvent(final String name) {
+			this.name = name;
+		}
+
+		public String getName() {
+			return name;
+		}
+	}
+}