Add support for BeanRegistrar registration on GenericApplicationContext

Closes gh-34574

spring-context/src/main/java/org/springframework/context/annotation/AnnotationConfigRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.context.annotation;
 
+import org.springframework.beans.factory.BeanRegistrar;
+
 /**
  * Common interface for annotation config application contexts,
  * defining {@link #register} and {@link #scan} methods.
@@ -26,17 +28,33 @@ package org.springframework.context.annotation;
 public interface AnnotationConfigRegistry {
 
 	/**
-	 * Register one or more component classes to be processed.
+	 * Invoke the given registrars for registering their beans with this
+	 * application context.
+	 * <p>This can be used to register custom beans without inferring
+	 * annotation-based characteristics for primary/fallback/lazy-init,
+	 * rather specifying those programmatically if needed.
+	 * @param registrars one or more {@link BeanRegistrar} instances
+	 * @since 7.0
+	 * @see #register(Class[])
+	 */
+	void register(BeanRegistrar... registrars);
+
+	/**
+	 * Register one or more component classes to be processed, inferring
+	 * annotation-based characteristics for primary/fallback/lazy-init
+	 * just like for scanned component classes.
 	 * <p>Calls to {@code register} are idempotent; adding the same
 	 * component class more than once has no additional effect.
 	 * @param componentClasses one or more component classes,
 	 * for example, {@link Configuration @Configuration} classes
+	 * @see #scan(String...)
 	 */
 	void register(Class<?>... componentClasses);
 
 	/**
 	 * Perform a scan within the specified base packages.
 	 * @param basePackages the packages to scan for component classes
+	 * @see #register(Class[])
 	 */
 	void scan(String... basePackages);
 

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

@@ -30,6 +30,7 @@ import org.springframework.aot.hint.support.ClassHintUtils;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanDefinitionStoreException;
+import org.springframework.beans.factory.BeanRegistrar;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
@@ -38,6 +39,7 @@ import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.config.SmartInstantiationAwareBeanPostProcessor;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
+import org.springframework.beans.factory.support.BeanRegistryAdapter;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.MergedBeanDefinitionPostProcessor;
 import org.springframework.beans.factory.support.RootBeanDefinition;
@@ -594,6 +596,21 @@ public class GenericApplicationContext extends AbstractApplicationContext implem
 		registerBeanDefinition(nameToUse, beanDefinition);
 	}
 
+	/**
+	 * Invoke the given registrars for registering their beans with this
+	 * application context.
+	 * <p>This can be used to apply encapsulated pieces of programmatic
+	 * bean registration to this application context without relying on
+	 * individual calls to its context-level {@code registerBean} methods.
+	 * @param registrars one or more {@link BeanRegistrar} instances
+	 * @since 7.0
+	 */
+	public void register(BeanRegistrar... registrars) {
+		for (BeanRegistrar registrar : registrars) {
+			new BeanRegistryAdapter(this.beanFactory, getEnvironment(), registrar.getClass()).register(registrar);
+		}
+	}
+
 
 	/**
 	 * {@link RootBeanDefinition} subclass for {@code #registerBean} based