Java – how to implement the same interface multiple times, but with different generics?

There is already an answer to this question: > how to make a Java class that implements one interface with two generic types? six

public interface EventListener<T extends Event>
{
    public void onEvent(T event);
}

Now, I want to implement this interface in the following ways:

class Foo implements EventListener<LoginEvent>,EventListener<logoutEvent>
{

    @Override
    public void onEvent(LoginEvent event)
    {

    }

    @Override
    public void onEvent(logoutEvent event)
    {

    }
}

However, this gives me an error: copy class com foo. EventListener on line:

class Foo implements EventListener<LoginEvent>,EventListener<logoutEvent>

Can I implement the interface twice with different generics? If not, what can I do next to achieve what I do here?

Solution

You need to use internal or anonymous classes for example

class Foo {
   public EventListener<X> asXListener() {
      return new EventListener<X>() {
          // code here can refer to Foo
      }
   }


  public EventListener<Y> asYListener() {
      return new EventListener<Y>() {
          // code here can refer to Foo
      }
   }
}