Hello there!
I have just found out something that really scared me!
I am using for this example 2 Decorators for one Interface and a simple
implementation, like this:
interface Service extends Serializable{
public Object getSomething(int value);
public boolean test(String text);
}
-----------------
public class MyService implements Service {
/* Used somewhere else to be able to use decorators and interceptors */
@Inject
private Service delegate;
public boolean test(String text){
return false;
}
}
-----------------
@Decorator
public abstract class ServiceDecoratorA implements Service {
@Delegate
@Inject
private Service delegate;
public boolean test(String text){
Object o = delegate.getSomething();
if(/*condition*/){
return true;
} else {
return delegate.test(text);
}
}
}
----------------
@Decorator
public abstract class ServiceDecoratorB implements Service {
@Delegate
@Inject
private Service delegate;
public boolean test(String text){
Object o = delegate.getSomething();
if(/*condition*/){
return true;
} else {
return delegate.test(text);
}
}
}
Invocation(Through EL): #{myService.test('aString')}
Expected Invocation-Chain:
OWB-Proxy.test(String)->...->ServiceDecoratorA.test(String)->ServiceDecoratorB.test(String)->MyService.test(String)
Actual Invocation-Chain:
OWB-Proxy.test(String)->...->ServiceDecoratorA.test(String)->MyService.test(String)
When I call the method test(String) decorator A is accessed when the
condition evaluates to false I would expect the next decorator to be
called, instead MyService.test(String) is called. If I put the
expression delegate.test(String) to the first line in the decorator
method, temporary put the result in a local var and return the local
vars content, everything works as expected.
I think that the invocation of the delegate mixes up a state of the OWB
proxy or so. I have no idea about what happens here but it sucks and I
think that this behavior is wrong.
I fixed this problem right now with temporary saving the delegates
return into a local var and the do other invocations on the delegate.
Is this a bug or is it not allowed to call other methods than the
decorated one in the decorator method?
Regards,
Christian
