Avoid multiple DeferredRepositoryInitializationListener registrations in RepositoryConfigurationDelegate.

Closes #3287
Original pull request: #3219

Author: xeounxzxu

src/main/java/org/springframework/data/repository/config/RepositoryConfigurationDelegate.java

@@ -15,28 +15,13 @@
  */
 package org.springframework.data.repository.config;
 
-import java.lang.reflect.TypeVariable;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.beans.factory.config.DependencyDescriptor;
 import org.springframework.beans.factory.parsing.BeanComponentDefinition;
-import org.springframework.beans.factory.support.AutowireCandidateResolver;
-import org.springframework.beans.factory.support.BeanDefinitionBuilder;
-import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
-import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.DefaultListableBeanFactory;
-import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.beans.factory.support.*;
 import org.springframework.context.annotation.ContextAnnotationAutowireCandidateResolver;
 import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.core.ResolvableType;
@@ -57,6 +42,10 @@
 import org.springframework.util.Assert;
 import org.springframework.util.StopWatch;
 
+import java.lang.reflect.TypeVariable;
+import java.util.*;
+import java.util.stream.Collectors;
+
 /**
  * Delegate for configuration integration to reuse the general way of detecting repositories. Customization is done by
  * providing a configuration format specific {@link RepositoryConfigurationSource} (currently either XML or annotations
@@ -92,7 +81,7 @@ public class RepositoryConfigurationDelegate {
 	 * @param environment must not be {@literal null}.
 	 */
 	public RepositoryConfigurationDelegate(RepositoryConfigurationSource configurationSource,
-			ResourceLoader resourceLoader, Environment environment) {
+										   ResourceLoader resourceLoader, Environment environment) {
 
 		this.isXml = configurationSource instanceof XmlRepositoryConfigurationSource;
 		boolean isAnnotation = configurationSource instanceof AnnotationRepositoryConfigurationSource;
@@ -117,7 +106,7 @@ public RepositoryConfigurationDelegate(RepositoryConfigurationSource configurati
 	 *         {@link Environment}.
 	 */
 	private static Environment defaultEnvironment(@Nullable Environment environment,
-			@Nullable ResourceLoader resourceLoader) {
+												  @Nullable ResourceLoader resourceLoader) {
 
 		if (environment != null) {
 			return environment;
@@ -136,7 +125,7 @@ private static Environment defaultEnvironment(@Nullable Environment environment,
 	 * @see org.springframework.beans.factory.support.BeanDefinitionRegistry
 	 */
 	public List<BeanComponentDefinition> registerRepositoriesIn(BeanDefinitionRegistry registry,
-			RepositoryConfigurationExtension extension) {
+																RepositoryConfigurationExtension extension) {
 
 		if (logger.isInfoEnabled()) {
 			logger.info(LogMessage.format("Bootstrapping Spring Data %s repositories in %s mode.", //
@@ -222,7 +211,7 @@ public List<BeanComponentDefinition> registerRepositoriesIn(BeanDefinitionRegist
 	}
 
 	private void registerAotComponents(BeanDefinitionRegistry registry, RepositoryConfigurationExtension extension,
-			Map<String, RepositoryConfigurationAdapter<?>> metadataByRepositoryBeanName) {
+									   Map<String, RepositoryConfigurationAdapter<?>> metadataByRepositoryBeanName) {
 
 		BeanDefinitionBuilder repositoryAotProcessor = BeanDefinitionBuilder
 				.rootBeanDefinition(extension.getRepositoryAotProcessor()).setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
@@ -245,7 +234,7 @@ private void registerAotComponents(BeanDefinitionRegistry registry, RepositoryCo
 	 * @param registry must not be {@literal null}.
 	 */
 	private static void potentiallyLazifyRepositories(Map<String, RepositoryConfiguration<?>> configurations,
-			BeanDefinitionRegistry registry, BootstrapMode mode) {
+													  BeanDefinitionRegistry registry, BootstrapMode mode) {
 
 		if (!DefaultListableBeanFactory.class.isInstance(registry) || BootstrapMode.DEFAULT.equals(mode)) {
 			return;
@@ -272,8 +261,10 @@ private static void potentiallyLazifyRepositories(Map<String, RepositoryConfigur
 
 			logger.debug("Registering deferred repository initialization listener.");
 
-			beanFactory.registerSingleton(DeferredRepositoryInitializationListener.class.getName(),
-					new DeferredRepositoryInitializationListener(beanFactory));
+			if (!beanFactory.containsBean(DeferredRepositoryInitializationListener.class.getName())) {
+				beanFactory.registerSingleton(DeferredRepositoryInitializationListener.class.getName(),
+						new DeferredRepositoryInitializationListener(beanFactory));
+			}
 		}
 	}
 

src/test/java/org/springframework/data/repository/config/RepositoryConfigurationDelegateUnitTests.java

@@ -15,13 +15,6 @@
  */
 package org.springframework.data.repository.config;
 
-import static org.assertj.core.api.Assertions.*;
-
-import java.lang.reflect.TypeVariable;
-import java.util.List;
-import java.util.Optional;
-import java.util.UUID;
-
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mockito;
@@ -59,11 +52,19 @@
 import org.springframework.data.repository.sample.AddressRepositoryClient;
 import org.springframework.data.repository.sample.ProductRepository;
 
+import java.lang.reflect.TypeVariable;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
 /**
  * Unit tests for {@link RepositoryConfigurationDelegate}.
  *
  * @author Oliver Gierke
  * @author Mark Paluch
+ * @author xeounxzxu
  * @soundtrack Richard Spaven - Tribute (Whole Other*)
  */
 @ExtendWith(MockitoExtension.class)
@@ -109,7 +110,16 @@ void registersDeferredRepositoryInitializationListener() {
 		var beanFactory = assertLazyRepositoryBeanSetup(DeferredConfig.class);
 
 		assertThat(beanFactory.getBeanNamesForType(DeferredRepositoryInitializationListener.class)).isNotEmpty();
+	}
+
+	@Test
+	void registersMultiDeferredRepositoryInitializationListener() {
+
+		var beanFactory = assertLazyRepositoryBeanSetup(DeferredConfig.class, OtherDeferredConfig.class);
 
+		assertThat(beanFactory.getBeanNamesForType(DeferredRepositoryInitializationListener.class)).isNotEmpty();
+		assertThat(beanFactory.getBeanNamesForType(AddressRepository.class)).isNotEmpty();
+		assertThat(beanFactory.getBeanNamesForType(ProductRepository.class)).isNotEmpty();
 	}
 
 	@Test // DATACMNS-1832
@@ -276,9 +286,9 @@ void considersGenericLength() {
 		assertThat(it.getGeneric(1).resolve()).isEqualTo(Person.class);
 	}
 
-	private static ListableBeanFactory assertLazyRepositoryBeanSetup(Class<?> configClass) {
+	private static ListableBeanFactory assertLazyRepositoryBeanSetup(Class<?>... componentClasses) {
 
-		var context = new AnnotationConfigApplicationContext(configClass);
+		var context = new AnnotationConfigApplicationContext(componentClasses);
 
 		assertThat(context.getDefaultListableBeanFactory().getAutowireCandidateResolver())
 				.isInstanceOf(LazyRepositoryInjectionPointResolver.class);
@@ -309,6 +319,12 @@ static class LazyConfig {}
 			bootstrapMode = BootstrapMode.DEFERRED)
 	static class DeferredConfig {}
 
+	@ComponentScan(basePackageClasses = ProductRepository.class)
+	@EnableRepositories(basePackageClasses = ProductRepository.class,
+			includeFilters = @Filter(type = FilterType.ASSIGNABLE_TYPE, classes = AddressRepository.class),
+			bootstrapMode = BootstrapMode.DEFERRED)
+	static class OtherDeferredConfig {}
+
 	@EnableRepositories(basePackageClasses = MyOtherRepository.class,
 			includeFilters = @Filter(type = FilterType.ASSIGNABLE_TYPE, classes = MyOtherRepository.class),
 			excludeFilters = @Filter(type = FilterType.ASSIGNABLE_TYPE, classes = MyOtherRepositoryImpl.class))