Introduce removeApplicationListener method at ApplicationContext level

Closes gh-14023

Author: jhoeller

spring-context/src/main/java/org/springframework/context/ConfigurableApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -169,6 +169,14 @@ public interface ConfigurableApplicationContext extends ApplicationContext, Life
 	 */
 	void addApplicationListener(ApplicationListener<?> listener);
 
+	/**
+	 * Remove the given ApplicationListener from this context's set of listeners,
+	 * assuming it got registered via {@link #addApplicationListener} before.
+	 * @param listener the ApplicationListener to deregister
+	 * @since 6.0
+	 */
+	void removeApplicationListener(ApplicationListener<?> listener);
+
 	/**
 	 * Specify the ClassLoader to load class path resources and bean classes with.
 	 * <p>This context class loader will be passed to the internal bean factory.

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -534,6 +534,15 @@ public void addApplicationListener(ApplicationListener<?> listener) {
 		this.applicationListeners.add(listener);
 	}
 
+	@Override
+	public void removeApplicationListener(ApplicationListener<?> listener) {
+		Assert.notNull(listener, "ApplicationListener must not be null");
+		if (this.applicationEventMulticaster != null) {
+			this.applicationEventMulticaster.removeApplicationListener(listener);
+		}
+		this.applicationListeners.remove(listener);
+	}
+
 	/**
 	 * Return the list of statically specified ApplicationListeners.
 	 */