Support abstract @⁠Configuration classes without @⁠Bean methods again

Historically, @⁠Configuration classes that did not declare @⁠Bean
methods were allowed to be abstract. However, the changes made in
76a6b9ea79 introduced a regression that prevents such classes from
being abstract, resulting in a BeanInstantiationException. This change
in behavior is caused by the fact that such a @⁠Configuration class is
no longer replaced by a concrete subclass created dynamically by CGLIB.

This commit restores support for abstract @⁠Configuration classes
without @⁠Bean methods by modifying the "no enhancement required" check
in ConfigurationClassParser.

See gh-34486
Closes gh-34663
This commit is contained in:
Sam Brannen 2025-03-29 16:45:39 +01:00
parent 36d9357f94
commit 044258f085
2 changed files with 26 additions and 3 deletions

View File

@ -179,8 +179,9 @@ class ConfigurationClassParser {
}
// Downgrade to lite (no enhancement) in case of no instance-level @Bean methods.
if (!configClass.hasNonStaticBeanMethods() && ConfigurationClassUtils.CONFIGURATION_CLASS_FULL.equals(
bd.getAttribute(ConfigurationClassUtils.CONFIGURATION_CLASS_ATTRIBUTE))) {
if (!configClass.getMetadata().isAbstract() && !configClass.hasNonStaticBeanMethods() &&
ConfigurationClassUtils.CONFIGURATION_CLASS_FULL.equals(
bd.getAttribute(ConfigurationClassUtils.CONFIGURATION_CLASS_ATTRIBUTE))) {
bd.setAttribute(ConfigurationClassUtils.CONFIGURATION_CLASS_ATTRIBUTE,
ConfigurationClassUtils.CONFIGURATION_CLASS_LITE);
}

View File

@ -129,6 +129,22 @@ class ConfigurationClassPostProcessorTests {
assertThat(beanFactory.getDependentBeans("config")).contains("bar");
}
@Test // gh-34663
void enhancementIsPresentForAbstractConfigClassWithoutBeanMethods() {
beanFactory.registerBeanDefinition("config", new RootBeanDefinition(AbstractConfigWithoutBeanMethods.class));
ConfigurationClassPostProcessor pp = new ConfigurationClassPostProcessor();
pp.postProcessBeanFactory(beanFactory);
RootBeanDefinition beanDefinition = (RootBeanDefinition) beanFactory.getBeanDefinition("config");
assertThat(beanDefinition.hasBeanClass()).isTrue();
assertThat(beanDefinition.getBeanClass().getName()).contains(ClassUtils.CGLIB_CLASS_SEPARATOR);
Foo foo = beanFactory.getBean("foo", Foo.class);
Bar bar = beanFactory.getBean("bar", Bar.class);
assertThat(bar.foo).isSameAs(foo);
assertThat(beanFactory.getDependentBeans("foo")).contains("bar");
String[] dependentsOfSingletonBeanConfig = beanFactory.getDependentBeans(SingletonBeanConfig.class.getName());
assertThat(dependentsOfSingletonBeanConfig).containsOnly("foo", "bar");
}
@Test
void enhancementIsNotPresentForProxyBeanMethodsFlagSetToFalse() {
beanFactory.registerBeanDefinition("config", new RootBeanDefinition(NonEnhancedSingletonBeanConfig.class));
@ -181,7 +197,7 @@ class ConfigurationClassPostProcessorTests {
assertThat(bar.foo).isNotSameAs(foo);
}
@Test
@Test // gh-34486
void enhancementIsNotPresentWithEmptyConfig() {
beanFactory.registerBeanDefinition("config", new RootBeanDefinition(EmptyConfig.class));
ConfigurationClassPostProcessor pp = new ConfigurationClassPostProcessor();
@ -1195,6 +1211,12 @@ class ConfigurationClassPostProcessorTests {
}
}
@Configuration
@Import(SingletonBeanConfig.class)
abstract static class AbstractConfigWithoutBeanMethods {
// This class intentionally does NOT declare @Bean methods.
}
@Configuration
static final class EmptyConfig {
}