RoutingFunctionEnvironmentPostProcessor v4.3.1 throws ClasscastException when spring-cloud-starter-bootstrap is in the classpath

[pgehl]

Describe the issue
We upgraded our application to spring-cloud version 2025.0.1 (spring-cloud-stream v4.3.1) from 2025.0.0 (spring-cloud-stream v4.3.0).

Our application fails to start.

The application uses org.springframework.cloud:spring-cloud-starter-bootstrap .

RoutingFunctionEnvironmentPostProcessor throws
java.lang.ClassCastException: class org.springframework.cloud.bootstrap.BootstrapApplicationListener$1 cannot be cast to class org.springframework.core.env.StandardEnvironment

To Reproduce
Steps to reproduce the behavior:

1. Upgrade spring-cloud to version 2025.0.1
2. Add org.springframework.cloud:spring-cloud-starter-bootstrap in the classpath
3. Use org.springframework.cloud:spring-cloud-stream-binder-kafka
4. See error

Version of the framework
spring-cloud version 2025.0.1

Expected behavior
application should start without exception

Additional context
In version 4.3.0
RoutingFunctionEnvironmentPostProcessor has the following method:

@Override
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
	String name = environment.getProperty("spring.cloud.function.definition");
	if (StringUtils.hasText(name) && (
			name.equals(RoutingFunction.FUNCTION_NAME) ||
			name.contains(RoutingFunction.FUNCTION_NAME + "|") ||
			name.contains("|" + RoutingFunction.FUNCTION_NAME)
		)) {
		((StandardEnvironment) environment).getSystemProperties()
			.putIfAbsent("spring.cloud.function.routing.enabled", "true");
	}
}

(StandardEnvironment) environment casting is only done when environment.getProperty("spring.cloud.function.definition") has text.

In version 4.3.1
RoutingFunctionEnvironmentPostProcessor has the following method:

@Override
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
	String name = environment.getProperty("spring.cloud.function.definition");
	if (StringUtils.hasText(name) && (
			name.equals(RoutingFunction.FUNCTION_NAME) ||
			name.contains(RoutingFunction.FUNCTION_NAME + "|") ||
			name.contains("|" + RoutingFunction.FUNCTION_NAME)
		)) {
		((StandardEnvironment) environment).getSystemProperties()
			.putIfAbsent("spring.cloud.function.routing.enabled", "true");
	}
	// perhaps mpve it to separate class as it doesn't have much to do with RoutingFunction
	((StandardEnvironment) environment).getSystemProperties()
		.putIfAbsent("spring.cloud.function.configuration.default.copy-input-headers", "true");
}

The casting is done even if environment.getProperty("spring.cloud.function.definition") has no text.

[SingKS8]

same issue if both "spring-cloud-stream" and "spring-cloud-starter-bootstrap" are in the classpath

[qiuchsh]

发现同样的错误，跟踪进展