IKeyReceiver.java

public interface IKeyReceiver
{
	void onKeypress(EntityPlayer player, KeyBinding ... keyBindings);
}

KeyHandler.java

public class KeyHandler
{
	private static List<RegisteredKeybinding> registered = new ArrayList<RegisteredKeybinding>();
	
	public static void registerKeybindsForNotification(IKeyReceiver callbackReceiver, KeyBinding... keyBindings)
	{
		registered.add(new RegisteredKeybinding(callbackReceiver, keyBindings));
	}
	
	@SubscribeEvent
	public void clientKeyListener(TickEvent.PlayerTickEvent event)
	{
		if(event.side == Side.CLIENT && event.phase == TickEvent.Phase.START)
		{
			for(RegisteredKeybinding reg : registered)
			{
				for(KeyBinding k : reg.keyBindings)
				{
					if(k.isKeyDown())
					{
						reg.receiver.onKeypress(event.player, reg.keyBindings);
						break;
					}
				}
			}
		}
	}
}

RegisteredKeybind.java

public class RegisteredKeybinding
{
	KeyBinding[] keyBindings;
	IKeyReceiver receiver;
	
	public RegisteredKeybinding(IKeyReceiver receiver, KeyBinding ... keyBindings)
	{
		this.keyBindings = keyBindings;
		this.receiver = receiver;
	}
}