Improve JpaBaseConfiguration to resolve beans lazily to avoid circular reference

Fix GH-50797 and GH-50749

Signed-off-by: Yanming Zhou <zhouyanming@gmail.com>

Author: quaff

module/spring-boot-hibernate/src/test/java/org/springframework/boot/hibernate/autoconfigure/HibernateJpaAutoConfigurationTests.java

@@ -1017,6 +1017,15 @@ void whenSpringJpaGenerateDdlIsTrueSpringJpaHibernateDdlAutoIsCreateAndJakartaSc
 			.run((context) -> assertThat(tablesFrom(context)).doesNotContain("CITY"));
 	}
 
+	@Test // GH-50797
+	void circularReference() {
+		this.contextRunner.withUserConfiguration(CircularReferenceConfiguration.class).run((context) -> {
+			assertThat(context).hasSingleBean(DataSource.class);
+			assertThat(context).hasSingleBean(JpaTransactionManager.class);
+			assertThat(context).hasSingleBean(EntityManagerFactory.class);
+		});
+	}
+
 	private List<String> tablesFrom(AssertableApplicationContext context) {
 		DataSource dataSource = context.getBean(DataSource.class);
 		JdbcTemplate jdbc = new JdbcTemplate(dataSource);
@@ -1474,4 +1483,13 @@ SimpleAsyncTaskExecutor applicationTaskExecutor() {
 
 	}
 
+	@Configuration
+	static class CircularReferenceConfiguration extends MultipleAsyncTaskExecutorsConfiguration {
+
+		CircularReferenceConfiguration(PlatformTransactionManager transactionManager) {
+
+		}
+
+	}
+
 }

module/spring-boot-jpa/src/main/java/org/springframework/boot/jpa/autoconfigure/JpaBaseConfiguration.java

@@ -29,6 +29,7 @@
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.boot.autoconfigure.AutoConfigurationPackages;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBooleanProperty;
@@ -124,8 +125,9 @@ public JpaVendorAdapter jpaVendorAdapter() {
 	public EntityManagerFactoryBuilder entityManagerFactoryBuilder(JpaVendorAdapter jpaVendorAdapter,
 			ObjectProvider<PersistenceUnitManager> persistenceUnitManager,
 			ObjectProvider<EntityManagerFactoryBuilderCustomizer> customizers,
-			Map<String, AsyncTaskExecutor> taskExecutors) {
-		@Nullable AsyncTaskExecutor bootstrapExecutor = determineBootstrapExecutor(taskExecutors);
+			ObjectProvider<AsyncTaskExecutor> taskExecutors,
+			@Qualifier(TaskExecutionAutoConfiguration.APPLICATION_TASK_EXECUTOR_BEAN_NAME) ObjectProvider<AsyncTaskExecutor> applicationTaskExecutor) {
+		@Nullable AsyncTaskExecutor bootstrapExecutor = determineBootstrapExecutor(taskExecutors, applicationTaskExecutor);
 		EntityManagerFactoryBuilder builder = new EntityManagerFactoryBuilder(jpaVendorAdapter,
 				this::buildJpaProperties, persistenceUnitManager.getIfAvailable(), null, bootstrapExecutor);
 		if (this.properties.getBootstrap() == Bootstrap.ASYNC) {
@@ -136,9 +138,10 @@ public EntityManagerFactoryBuilder entityManagerFactoryBuilder(JpaVendorAdapter
 		return builder;
 	}
 
-	private @Nullable AsyncTaskExecutor determineBootstrapExecutor(Map<String, AsyncTaskExecutor> taskExecutors) {
-		return (taskExecutors.size() == 1) ? taskExecutors.values().iterator().next()
-				: taskExecutors.get(TaskExecutionAutoConfiguration.APPLICATION_TASK_EXECUTOR_BEAN_NAME);
+	private @Nullable AsyncTaskExecutor determineBootstrapExecutor(ObjectProvider<AsyncTaskExecutor> taskExecutors,
+			ObjectProvider<AsyncTaskExecutor> applicationTaskExecutor) {
+		@Nullable AsyncTaskExecutor asyncTaskExecutor = taskExecutors.getIfUnique();
+		return (asyncTaskExecutor != null) ? asyncTaskExecutor : applicationTaskExecutor.getIfAvailable();
 	}
 
 	private Map<String, ?> buildJpaProperties(DataSource dataSource) {