The DefaultBinderFactory.propagateSharedBeans() is looking for shared bean in wrong context

[mayur-solace]

The call to the this.propagateSharedBeans(...) is passing the fromContext and toContext contexts in wrong order. The binderProducingContext should be toContext.

Also calling the binderProducingContext.refresh() before call to this.propagateSharedBeans(..) creates new beans (that depends on shared beans) before shared beans are available for auto-wiring.

Code snippet from org.springframework.cloud.stream.binder.DefaultBinderFactory

 if (refresh) {
	binderProducingContext.refresh();
	if (!useApplicationContextAsParent || "integration".equals(binderType.getDefaultName())) {
		this.propagateSharedBeans((GenericApplicationContext) this.context, binderProducingContext);
	}
}

should the call be instead....

if (refresh) {
	if (!useApplicationContextAsParent || "integration".equals(binderType.getDefaultName())) {
		this.propagateSharedBeans(binderProducingContext, (GenericApplicationContext) this.context);
	}
        binderProducingContext.refresh();
}

is there a tests that covers shared bean propagation ?

spring-cloud-stream/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binder/DefaultBinderFactory.java

Line 484 in 29c3cd7

this.propagateSharedBeans((GenericApplicationContext) this.context, binderProducingContext);

[Nephery]

For context, we're getting this issue while trying to upgrade the Solace binder to Spring Cloud 2022.x since this binder needs to use shared.beans to share some beans from the parent context to binder contexts for the multiple systems setup.

[sobychacko]

cc @olegz

[olegz]

@Nephery
Sorry, somehow this issue got lost.
Can you guys elaborate a bit more on this? Beans are propagated from parent context to child one (binder context) to ensure that certain beans are available to the binder context. So doing it the other way around is definitely wrong especially in the cases where you have multiple binders of the same type (i.e., two Solace binders connected to different solace clusters)

So I want to understand better what issue you are really experiencing and how to reproduce it,.

[mayur-solace]

@olegz

Look at the call to the method and definition of the method.

this.propagateSharedBeans((GenericApplicationContext) this.context, binderProducingContext);

and

private void propagateSharedBeans(GenericApplicationContext toContext, GenericApplicationContext fromContext) { }

Here,
this.context - as per my understanding is the parent context and it is passed as toContext
binderProducingContext - is the child one (binder context) which is passed as fromContext

method propagateSharedBeans(toContext, fromContext) is trying to find the shared bean in binderProducingContext(i.e. fromContext) and inject it this.context (i.e. toContext). I think shared bean won't found in binderProducingContext

Let me know if my understanding is in correct.

[Nephery]

Can you guys elaborate a bit more on this? Beans are propagated from parent context to child one (binder context) to ensure that certain beans are available to the binder context. So doing it the other way around is definitely wrong especially in the cases where you have multiple binders of the same type (i.e., two Solace binders connected to different solace clusters)

@olegz the issue that we were facing was that shared.beans wasn't propagating beans from parent context to the child contexts. We aren't doing it the other way around.

To break down what we have:

1. We have two beans, SolaceMeterAccessor and SolaceMessageMeterBinder, instantiated in this @Configuration, SolaceMeterConfiguration.
2. SolaceMeterConfiguration is auto-configured in the parent context using the org.springframework.boot.autoconfigure.AutoConfiguration.imports file.
3. The SolaceMeterAccessor and SolaceMessageMeterBinder beans are then forwarded to the child contexts using the shared.beans file.
4. The beans are then autowired to the solace binder bean within the binder's context.
   • But instead of getting the shared bean, SolaceMeterAccessor, we're just getting null.

[Nephery]

@olegz this doesn't look like it works.

As @mayur-solace mentioned, we think this might be because binderProducingContext.refresh(); is being called before propagateSharedBeans() is invoked. The context might need to be refreshed after propagateSharedBeans() instead of before.

[olegz]

@Nephery Can you please try with the latest snapshot?

[Nephery]

@olegz I tested out the latest 4.1.2-SNAPSHOT, and it looks like this works now. Thanks for the fix!