Events in my objects!!!

Question

how can I make so that my objects define and do activate events (although they are not graphic objects)?
I have thought of creating a thread of events dispatch. But there is not a form easier of making it?
May be inner classes. But what does it happen to the objects sources that multiple objects listeners have?
PD: Forgive my English. I am learning...
Salu2

Answer 1

I have something this (please, some patience :-) ):
//Example: handle event (the event is Beep)
interface AlarmListener{
void Beep(String hour); //declare a event handler
//The class that "raise" an event Beep
class Clock{
AlarmListener theAlarmListener; //Referecne to an listener object
//Register an listener object
public addAlarmListener(AlarmListener theAlarmListener){
this.theAlarmListener = theAlarmListener;
private ringAlarm(){
theAlarmListener.Beep("10:00 P.M."); //Raise Beep event
class Guy implements AlarmListener{
public Guy(){
Clock clock = new Clock();
clock.addAlarmListener(this);
//Handle Beep event
void Beep(String hour){
System.out.println("Ohhh, its time of wake up!!!");
//End
But, in this model my source object have only an listener object.
This can be improved by a array, like this:
class Clock{
AlarmListener[] theAlarmListener = new AlarmListener[10];
private int i = 0;
//Register an listener object
public addAlarmListener(AlarmListener theAlarmListener){
this.theAlarmListener[i++] = theAlarmListener;
//More code...
making to a side the limitation of size of an array (although this can be managed somehow if it is necessary), the problem begining to be more and more complex... i.e., it is necessary to create a method for unregister a listener...
And, what about with multi-threads programs??? The addAlarmListener method should be synchronized or something??
It should have an easier way!
PD: I think that I have used the Delegate pattern in conjunction with some other pattern.
PD: Forget my English. It is terrible
Saludos