Fix @ConditionalOnBean with annotation early FactoryBean initialization

Update `OnBeanCondition` with a variant of `getBeanNamesForAnnotation`
that does not cause early `FactoryBean` initialization.

Fixes gh-38473

Author: philwebb

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnBeanCondition.java

@@ -36,6 +36,7 @@
 import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.config.SingletonBeanRegistry;
 import org.springframework.boot.autoconfigure.AutoConfigurationMetadata;
 import org.springframework.boot.autoconfigure.condition.ConditionMessage.Style;
 import org.springframework.context.annotation.Bean;
@@ -279,7 +280,7 @@ private Class<? extends Annotation> resolveAnnotationType(ClassLoader classLoade
 
 	private Set<String> collectBeanNamesForAnnotation(ListableBeanFactory beanFactory,
 			Class<? extends Annotation> annotationType, boolean considerHierarchy, Set<String> result) {
-		result = addAll(result, beanFactory.getBeanNamesForAnnotation(annotationType));
+		result = addAll(result, getBeanNamesForAnnotation(beanFactory, annotationType));
 		if (considerHierarchy) {
 			BeanFactory parent = ((HierarchicalBeanFactory) beanFactory).getParentBeanFactory();
 			if (parent instanceof ListableBeanFactory listableBeanFactory) {
@@ -289,6 +290,30 @@ private Set<String> collectBeanNamesForAnnotation(ListableBeanFactory beanFactor
 		return result;
 	}
 
+	private String[] getBeanNamesForAnnotation(ListableBeanFactory beanFactory,
+			Class<? extends Annotation> annotationType) {
+		Set<String> foundBeanNames = new LinkedHashSet<>();
+		for (String beanName : beanFactory.getBeanDefinitionNames()) {
+			if (beanFactory instanceof ConfigurableListableBeanFactory configurableListableBeanFactory) {
+				BeanDefinition beanDefinition = configurableListableBeanFactory.getBeanDefinition(beanName);
+				if (beanDefinition != null && beanDefinition.isAbstract()) {
+					continue;
+				}
+			}
+			if (beanFactory.findAnnotationOnBean(beanName, annotationType, false) != null) {
+				foundBeanNames.add(beanName);
+			}
+		}
+		if (beanFactory instanceof SingletonBeanRegistry singletonBeanRegistry) {
+			for (String beanName : singletonBeanRegistry.getSingletonNames()) {
+				if (beanFactory.findAnnotationOnBean(beanName, annotationType) != null) {
+					foundBeanNames.add(beanName);
+				}
+			}
+		}
+		return foundBeanNames.toArray(String[]::new);
+	}
+
 	private boolean containsBean(ConfigurableListableBeanFactory beanFactory, String beanName,
 			boolean considerHierarchy) {
 		if (considerHierarchy) {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/condition/ConditionalOnBeanTests.java

@@ -28,11 +28,13 @@
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.boot.autoconfigure.condition.ConditionEvaluationReport.ConditionAndOutcomes;
 import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -131,6 +133,19 @@ void beanProducedByFactoryBeanIsConsideredWhenMatchingOnAnnotation() {
 			});
 	}
 
+	@Test
+	void beanProducedByFactoryBeanIsConsideredWhenMatchingOnAnnotation2() {
+		this.contextRunner
+			.withUserConfiguration(EarlyInitializationFactoryBeanConfiguration.class,
+					EarlyInitializationOnAnnotationFactoryBeanConfiguration.class)
+			.run((context) -> {
+				assertThat(EarlyInitializationFactoryBeanConfiguration.calledWhenNoFrozen).as("calledWhenNoFrozen")
+					.isFalse();
+				assertThat(context).hasBean("bar");
+				assertThat(context).hasSingleBean(ExampleBean.class);
+			});
+	}
+
 	private void hasBarBean(AssertableApplicationContext context) {
 		assertThat(context).hasBean("bar");
 		assertThat(context.getBean("bar")).isEqualTo("bar");
@@ -352,6 +367,35 @@ String bar() {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class EarlyInitializationFactoryBeanConfiguration {
+
+		static boolean calledWhenNoFrozen;
+
+		@Bean
+		@TestAnnotation
+		static FactoryBean<?> exampleBeanFactoryBean(ApplicationContext applicationContext) {
+			// NOTE: must be static and return raw FactoryBean and not the subclass so
+			// Spring can't guess type
+			ConfigurableListableBeanFactory beanFactory = ((ConfigurableApplicationContext) applicationContext)
+				.getBeanFactory();
+			calledWhenNoFrozen = calledWhenNoFrozen || !beanFactory.isConfigurationFrozen();
+			return new ExampleFactoryBean();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnBean(annotation = TestAnnotation.class)
+	static class EarlyInitializationOnAnnotationFactoryBeanConfiguration {
+
+		@Bean
+		String bar() {
+			return "bar";
+		}
+
+	}
+
 	static class WithPropertyPlaceholderClassNameRegistrar implements ImportBeanDefinitionRegistrar {
 
 		@Override
@@ -518,7 +562,7 @@ static class OtherExampleBean extends ExampleBean {
 
 	}
 
-	@Target(ElementType.TYPE)
+	@Target({ ElementType.TYPE, ElementType.METHOD })
 	@Retention(RetentionPolicy.RUNTIME)
 	@Documented
 	@interface TestAnnotation {