Document that AOT processors are initialized during AOT processing

Closes gh-28866

Author: philwebb

spring-beans/src/main/java/org/springframework/beans/factory/aot/BeanFactoryInitializationAotProcessor.java

@@ -16,13 +16,25 @@
 
 package org.springframework.beans.factory.aot;
 
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.lang.Nullable;
 
 /**
  * AOT processor that makes bean factory initialization contributions by
  * processing {@link ConfigurableListableBeanFactory} instances.
  *
+ * <p>{@link BeanFactoryInitializationAotProcessor} implementations may be
+ * registered in a {@value AotServices#FACTORIES_RESOURCE_LOCATION} resource or
+ * as a bean.
+ *
+ * <p>
+ * Note: Using this interface on a registered bean will cause the bean
+ * <em>and</em> all of its dependencies to be initialized during AOT processing.
+ * We generally recommend that interface is only used with infrastructure beans
+ * such as {@link BeanFactoryPostProcessor} which have limited dependencies and
+ * are already initialized early in the bean factory lifecycle.
+ *
  * @author Phillip Webb
  * @author Stephane Nicoll
  * @since 6.0

spring-beans/src/main/java/org/springframework/beans/factory/aot/BeanRegistrationAotProcessor.java

@@ -16,13 +16,24 @@
 
 package org.springframework.beans.factory.aot;
 
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
 import org.springframework.beans.factory.support.RegisteredBean;
 import org.springframework.lang.Nullable;
 
 /**
  * AOT processor that makes bean registration contributions by processing
  * {@link RegisteredBean} instances.
  *
+ * <p>{@link BeanRegistrationAotProcessor} implementations may be registered in
+ * a {@value AotServices#FACTORIES_RESOURCE_LOCATION} resource or as a bean.
+ *
+ * <p>
+ * Note: Using this interface on a registered bean will cause the bean
+ * <em>and</em> all of its dependencies to be initialized during AOT processing.
+ * We generally recommend that interface is only used with infrastructure beans
+ * such as {@link BeanFactoryPostProcessor} which have limited dependencies and
+ * are already initialized early in the bean factory lifecycle.
+ *
  * @author Phillip Webb
  * @since 6.0
  * @see BeanRegistrationAotContribution