public PathMatchingResourcePatternResolver getResolver() {
		return resolver;
	}
An ApplicationListener which tracks which MessageBus implementation ought to be used so that it exposes a ClassLoader
that knows about the correct jar files for that bus.
<p>Make sure that this listener is triggered before the created ClassLoader is used.</p>

@author Eric Bottard
@author David Turanski
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/server/MessageBusClassLoaderFactory.java