Merge pull request #36251 from bbulgarelli

* pr/36251:
  Polish contribution
  Deprecate DelegatingApplicationContextInitializer and DelegatingApplicationListener

Closes gh-36251

spring-boot-project/spring-boot-docs/src/docs/asciidoc/howto/application.adoc

@@ -61,7 +61,6 @@ Spring Boot loads a number of such customizations for use internally from `META-
 There is more than one way to register additional customizations:
 
 * Programmatically, per application, by calling the `addListeners` and `addInitializers` methods on `SpringApplication` before you run it.
-* Declaratively, per application, by setting the `context.initializer.classes` or `context.listener.classes` properties.
 * Declaratively, for all applications, by adding a `META-INF/spring.factories` and packaging a jar file that the applications all use as a library.
 
 The `SpringApplication` sends some special `ApplicationEvents` to the listeners (some even before the context is created) and then registers the listeners for events published by the `ApplicationContext` as well.

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/DelegatingApplicationContextInitializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -38,7 +38,10 @@ import org.springframework.util.StringUtils;
  * @author Dave Syer
  * @author Phillip Webb
  * @since 1.0.0
+ * @deprecated since 3.2.0 for removal in 3.4.0 as property based initialization is no
+ * longer recommended
  */
+@Deprecated(since = "3.2.0", forRemoval = true)
 public class DelegatingApplicationContextInitializer
 		implements ApplicationContextInitializer<ConfigurableApplicationContext>, Ordered {
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/DelegatingApplicationListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2022 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -40,7 +40,10 @@ import org.springframework.util.StringUtils;
  * @author Dave Syer
  * @author Phillip Webb
  * @since 1.0.0
+ * @deprecated since 3.2.0 for removal in 3.4.0 as property based initialization is no
+ * longer recommended
  */
+@Deprecated(since = "3.2.0", forRemoval = true)
 public class DelegatingApplicationListener implements ApplicationListener<ApplicationEvent>, Ordered {
 
 	// NOTE: Similar to org.springframework.web.context.ContextLoader

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/DelegatingApplicationContextInitializerTests.java

@@ -36,6 +36,8 @@ import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException
  *
  * @author Phillip Webb
  */
+@Deprecated(since = "3.2.0", forRemoval = true)
+@SuppressWarnings("removal")
 class DelegatingApplicationContextInitializerTests {
 
 	private final DelegatingApplicationContextInitializer initializer = new DelegatingApplicationContextInitializer();

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/DelegatingApplicationListenerTests.java

@@ -37,6 +37,8 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Dave Syer
  */
+@Deprecated(since = "3.2.0", forRemoval = true)
+@SuppressWarnings("removal")
 class DelegatingApplicationListenerTests {
 
 	private final DelegatingApplicationListener listener = new DelegatingApplicationListener();