`@DynamicPropertySource`

@DynamicPropertySource is a method-level annotation that you can use to register dynamic properties to be added to the set of PropertySources in the Environment for an ApplicationContext loaded for an integration test. Dynamic properties are useful when you do not know the value of the properties upfront – for example, if the properties are managed by an external resource such as for a container managed by the Testcontainers project.

The following example demonstrates how to register a dynamic property:

Java
Kotlin

@ContextConfiguration
class MyIntegrationTests {

	static MyExternalServer server = // ...

	@DynamicPropertySource (1)
	static void dynamicProperties(DynamicPropertyRegistry registry) { (2)
		registry.add("server.port", server::getPort); (3)
	}

	// tests ...
}

1	Annotate a `static` method with `@DynamicPropertySource`.
2	Accept a `DynamicPropertyRegistry` as an argument.
3	Register a dynamic `server.port` property to be retrieved lazily from the server.

@ContextConfiguration
class MyIntegrationTests {

	companion object {

		@JvmStatic
		val server: MyExternalServer = // ...

		@DynamicPropertySource (1)
		@JvmStatic
		fun dynamicProperties(registry: DynamicPropertyRegistry) { (2)
			registry.add("server.port", server::getPort) (3)
		}
	}

	// tests ...
}

1	Annotate a `static` method with `@DynamicPropertySource`.
2	Accept a `DynamicPropertyRegistry` as an argument.
3	Register a dynamic `server.port` property to be retrieved lazily from the server.

See Context Configuration with Dynamic Property Sources for further details.