Implementing Generic Interface in Java

Question

I have a Java generics question I was hoping someone could answer. Consider the following code:

public interface Event{}
public class AddressChanged implemen         


        

Answer 1

An implementation like this won't work due to the constraints of the java specification. But if you're not afraid to use AOP or some sort of an IOC-Container you could use annotations for that. Than your Aspects or the container could manage the messaging infrastructure and call the methods you annotate.

First you have to create the annotations.

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface EventConsumer {}

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Handles{}

The you may annotate your class like that:

@EventConsumer
public class AddressHandler{
    @Handles
    public void handle(AddressChanged e){}
    @Handles
    public void handle(AddressDiscarded e){}
}