Revise test for ApplicationListener self injection

See gh-28322

spring-context/src/test/java/org/springframework/context/event/ApplicationContextEventTests.java

@@ -41,7 +41,7 @@ import org.springframework.context.ApplicationEventPublisherAware;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.PayloadApplicationEvent;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
-import org.springframework.context.event.test.self_inject.MyApplication;
+import org.springframework.context.event.test.self_inject.MyAspect;
 import org.springframework.context.event.test.self_inject.MyEventListener;
 import org.springframework.context.event.test.self_inject.MyEventPublisher;
 import org.springframework.context.support.AbstractApplicationContext;
@@ -280,17 +280,17 @@ public class ApplicationContextEventTests extends AbstractApplicationEventListen
 	 * Regression test for <a href="https://github.com/spring-projects/spring-framework/issues/28283">issue 28283</a>,
 	 * where event listeners proxied due to e.g.
 	 * <ul>
-	 *   <li>{@code @Transactional} annotations in their methods or</li>
-	 *   <li>being targeted by aspects</li>
+	 * <li>{@code @Transactional} annotations in their methods or</li>
+	 * <li>being targeted by aspects</li>
 	 * </ul>
 	 * were added to the list of application listener beans twice (both proxy and unwrapped target).
 	 */
 	@Test
 	public void eventForSelfInjectedProxiedListenerFiredOnlyOnce() {
-		String basePackage = MyApplication.class.getPackageName();
-		AbstractApplicationContext context = new AnnotationConfigApplicationContext(basePackage);
+		AbstractApplicationContext context = new AnnotationConfigApplicationContext(
+				MyAspect.class, MyEventListener.class, MyEventPublisher.class);
 		context.getBean(MyEventPublisher.class).publishMyEvent("hello");
-		assertThat(MyEventListener.eventCount).isEqualTo(1);
+		assertThat(context.getBean(MyEventListener.class).eventCount).isEqualTo(1);
 		context.close();
 	}
 

spring-context/src/test/java/org/springframework/context/event/test/self_inject/MyApplication.java

@@ -1,17 +0,0 @@
-package org.springframework.context.event.test.self_inject;
-
-import org.springframework.context.annotation.AnnotationConfigApplicationContext;
-import org.springframework.context.annotation.Configuration;
-import org.springframework.context.annotation.EnableAspectJAutoProxy;
-import org.springframework.context.support.AbstractApplicationContext;
-
-@Configuration
-@EnableAspectJAutoProxy(proxyTargetClass = true)
-public class MyApplication {
-	public static void main(String[] args) {
-		try (AbstractApplicationContext context = new AnnotationConfigApplicationContext("org.springframework.context.event.test.self_inject")) {
-			context.getBean(MyEventPublisher.class).publishMyEvent("hello");
-			assert MyEventListener.eventCount == 1 : "event listener must fire exactly once";
-		}
-	}
-}

spring-context/src/test/java/org/springframework/context/event/test/self_inject/MyAspect.java

@@ -1,15 +1,34 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.context.event.test.self_inject;
 
 import org.aspectj.lang.JoinPoint;
 import org.aspectj.lang.annotation.Aspect;
 import org.aspectj.lang.annotation.Before;
+
 import org.springframework.stereotype.Component;
 
 @Aspect
 @Component
 public class MyAspect {
+
 	@Before("within(org.springframework.context.event.test.self_inject.MyEventListener)")
 	public void myAdvice(JoinPoint joinPoint) {
-		//System.out.println(joinPoint);
+		// System.out.println(joinPoint);
 	}
+
 }

spring-context/src/test/java/org/springframework/context/event/test/self_inject/MyEvent.java

@@ -1,12 +1,31 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.context.event.test.self_inject;
 
 import org.springframework.context.ApplicationEvent;
 
+@SuppressWarnings("serial")
 public class MyEvent extends ApplicationEvent {
+
 	private String message;
 
 	public MyEvent(Object source, String message) {
 		super(source);
 		this.message = message;
 	}
+
 }

spring-context/src/test/java/org/springframework/context/event/test/self_inject/MyEventListener.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.context.event.test.self_inject;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -6,15 +22,15 @@ import org.springframework.stereotype.Component;
 
 @Component
 public class MyEventListener implements ApplicationListener<MyEvent> {
-	public static int eventCount;
 
-	@Autowired  // use '-Dspring.main.allow-circular-references=true' in Spring Boot >= 2.6.0
-	//@Lazy     // with '@Lazy', the problem does not occur
+	public int eventCount;
+
+	@Autowired
 	private MyEventListener eventDemoListener;
 
 	@Override
 	public void onApplicationEvent(MyEvent event) {
-		//System.out.println("Event: " + event);
 		eventCount++;
 	}
+
 }

spring-context/src/test/java/org/springframework/context/event/test/self_inject/MyEventPublisher.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 2002-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.context.event.test.self_inject;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -6,10 +22,12 @@ import org.springframework.stereotype.Component;
 
 @Component
 public class MyEventPublisher {
+
 	@Autowired
 	private ApplicationEventPublisher eventPublisher;
 
 	public void publishMyEvent(String message) {
 		eventPublisher.publishEvent(new MyEvent(this, message));
 	}
+
 }