AOP and REST

As a module developer, you may face a situation where you want to extend the behavior of a lower-level module's REST resource, without changing its URL. You can use Aspect-Oriented Programming (AOP) to achieve this.

To begin, create a new class annotated with both org.springframework.stereotype.Component and org.aspectj.lang.annotation.Aspect. Add Pointcuts and other annotations as dictated by AspectJ. For example, the code below will run after a return from the "getSample()" method of SampleAopResource in module "platformtestmodule":

@Component
@Aspect
public class SampleAopResourceListener {
 
	@Pointcut("execution(com.onenetwork.platformtestmodule.rest.SampleAopResource.Sample com.onenetwork.platformtestmodule.rest.SampleAopResource.getSample())")
	public void getSample() {
	}
 
	@AfterReturning(pointcut = "getSample()", returning = "sample")
	public Sample afterReturning(Sample sample) {
		sample.setValue("alteredSample");
	return sample;
	}
}

Once this is in place, make sure this class package is included in your *-app-context.xml spring file:

...
<context:component-scan base-package="com.onenetwork.aopsamplemodule.mpt,com.onenetwork.aopsamplemodule.rest"/>
...

Now, once you build and restart the server, your SampleAopResourceListener should be called at the conclusion of SampleAopResource.getSample(), before the values are provided to Jersey for serialization in the HTTP response.