Refine @ImportTestcontainers support

Refine logic so that bean names are no longer generated based on their
type and containers are started early.

See gh-35245

spring-boot-project/spring-boot-testcontainers/src/main/java/org/springframework/boot/testcontainers/context/ContainerFieldsImporter.java

@@ -22,9 +22,9 @@ import java.util.ArrayList;
 import java.util.List;
 
 import org.testcontainers.containers.Container;
+import org.testcontainers.lifecycle.Startable;
 
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.BeanNameGenerator;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
 
@@ -35,12 +35,14 @@ import org.springframework.util.ReflectionUtils;
  */
 class ContainerFieldsImporter {
 
-	void registerBeanDefinitions(BeanDefinitionRegistry registry, BeanNameGenerator importBeanNameGenerator,
+	void registerBeanDefinitions(BeanDefinitionRegistry registry, Class<?> definitionClass) {
-			Class<?> definitionClass) {
 		for (Field field : getContainerFields(definitionClass)) {
 			assertValid(field);
 			Container<?> container = getContainer(field);
-			registerBeanDefinition(registry, importBeanNameGenerator, field, container);
+			if (container instanceof Startable startable) {
+				startable.start();
+			}
+			registerBeanDefinition(registry, field, container);
 		}
 	}
 
@@ -66,11 +68,14 @@ class ContainerFieldsImporter {
 		return container;
 	}
 
-	private void registerBeanDefinition(BeanDefinitionRegistry registry, BeanNameGenerator importBeanNameGenerator,
+	private void registerBeanDefinition(BeanDefinitionRegistry registry, Field field, Container<?> container) {
-			Field field, Container<?> container) {
 		TestcontainerFieldBeanDefinition beanDefinition = new TestcontainerFieldBeanDefinition(field, container);
-		String beanName = importBeanNameGenerator.generateBeanName(beanDefinition, registry);
+		String beanName = generateBeanName(field);
 		registry.registerBeanDefinition(beanName, beanDefinition);
 	}
 
+	private String generateBeanName(Field field) {
+		return "importTestContainer.%s.%s".formatted(field.getDeclaringClass().getName(), field.getName());
+	}
+
 }

spring-boot-project/spring-boot-testcontainers/src/main/java/org/springframework/boot/testcontainers/context/ImportTestcontainersRegistrar.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.testcontainers.context;
 
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
-import org.springframework.beans.factory.support.BeanNameGenerator;
 import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
 import org.springframework.core.annotation.MergedAnnotation;
 import org.springframework.core.env.Environment;
@@ -48,8 +47,7 @@ class ImportTestcontainersRegistrar implements ImportBeanDefinitionRegistrar {
 	}
 
 	@Override
-	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry,
+	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
-			BeanNameGenerator importBeanNameGenerator) {
 		MergedAnnotation<ImportTestcontainers> annotation = importingClassMetadata.getAnnotations()
 			.get(ImportTestcontainers.class);
 		Class<?>[] definitionClasses = annotation.getClassArray(MergedAnnotation.VALUE);
@@ -57,13 +55,12 @@ class ImportTestcontainersRegistrar implements ImportBeanDefinitionRegistrar {
 			Class<?> importingClass = ClassUtils.resolveClassName(importingClassMetadata.getClassName(), null);
 			definitionClasses = new Class<?>[] { importingClass };
 		}
-		registerBeanDefinitions(registry, importBeanNameGenerator, definitionClasses);
+		registerBeanDefinitions(registry, definitionClasses);
 	}
 
-	private void registerBeanDefinitions(BeanDefinitionRegistry registry, BeanNameGenerator importBeanNameGenerator,
+	private void registerBeanDefinitions(BeanDefinitionRegistry registry, Class<?>[] definitionClasses) {
-			Class<?>[] definitionClasses) {
 		for (Class<?> definitionClass : definitionClasses) {
-			this.containerFieldsImporter.registerBeanDefinitions(registry, importBeanNameGenerator, definitionClass);
+			this.containerFieldsImporter.registerBeanDefinitions(registry, definitionClass);
 			if (this.dynamicPropertySourceMethodsImporter != null) {
 				this.dynamicPropertySourceMethodsImporter.registerDynamicPropertySources(definitionClass);
 			}

spring-boot-project/spring-boot-testcontainers/src/main/java/org/springframework/boot/testcontainers/context/TestcontainerFieldBeanDefinition.java

@@ -40,6 +40,7 @@ class TestcontainerFieldBeanDefinition extends RootBeanDefinition implements Tes
 		this.annotations = MergedAnnotations.from(field);
 		this.setBeanClass(container.getClass());
 		setInstanceSupplier(() -> container);
+		setRole(ROLE_INFRASTRUCTURE);
 	}
 
 	@Override