DynamicPropertyDefinitionRegistrar registers single Bean

Closes gh-70

Author: rwinch

spring-boot-testjars/src/main/java/org/springframework/experimental/boot/test/context/DynamicPropertyDefinitionRegistrar.java

@@ -43,6 +43,8 @@
  */
 class DynamicPropertyDefinitionRegistrar implements ImportBeanDefinitionRegistrar {
 
+	public static final String REGISTRAR_BEAN_NAME = "testjarsDynamicPropertyRegistryPropertyRegistrar";
+
 	private final DynamicPropertyRegistryPropertyFactory registryPropertyFactory;
 
 	private final BeanFactory beanFactory;
@@ -57,6 +59,9 @@ class DynamicPropertyDefinitionRegistrar implements ImportBeanDefinitionRegistra
 
 	@Override
 	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
+		if (registry.containsBeanDefinition(REGISTRAR_BEAN_NAME)) {
+			return;
+		}
 		if (this.beanFactory instanceof ConfigurableListableBeanFactory listableBeanFactory) {
 			if (ClassUtils.isPresent("org.springframework.test.context.DynamicPropertyRegistrar",
 					getClass().getClassLoader())) {
@@ -85,8 +90,7 @@ private void registerDynamicPropertyRegistrar(ConfigurableListableBeanFactory be
 		BeanDefinitionBuilder registrarBdb = BeanDefinitionBuilder
 				.rootBeanDefinition(DynamicPropertyRegistryPropertyRegistrar.class);
 		registrarBdb.addConstructorArgValue(properties);
-		registry.registerBeanDefinition("testjarsDynamicPropertyRegistryPropertyRegistrar",
-				registrarBdb.getBeanDefinition());
+		registry.registerBeanDefinition(REGISTRAR_BEAN_NAME, registrarBdb.getBeanDefinition());
 	}
 
 	private void registerTestcontainersPropertySource(ConfigurableListableBeanFactory beanFactory,

spring-boot-testjars/src/test/java/org/springframework/experimental/boot/test/context/DynamicPropertyDefinitionRegistrarTests.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.experimental.boot.test.context;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Rob Winch
+ */
+class DynamicPropertyDefinitionRegistrarTests {
+
+	@Test
+	void importTwiceAndAllowBeanOverridingFalseThenNoException() {
+		try (AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext()) {
+			context.register(ImportTwiceTestConfiguration.class);
+			context.setAllowBeanDefinitionOverriding(false);
+			context.refresh();
+		}
+	}
+
+	@Configuration
+	static class ImportTwiceTestConfiguration {
+
+		@EnableDynamicProperty
+		@Configuration
+		static class Config1 {
+
+		}
+
+		@EnableDynamicProperty
+		@Configuration
+		static class Config2 {
+
+		}
+
+	}
+
+}