ObservableService.java

package husacct.common.services;

import java.util.ArrayList;

import org.apache.log4j.Logger;

public class ObservableService {
	
	private final Logger logger = Logger.getLogger(ObservableService.class);
	private ArrayList<IServiceListener> listeners = new ArrayList<IServiceListener>();
	
	public void addServiceListener(IServiceListener listener){
		listeners.add(listener);
	}
	
	public void notifyServiceListeners(){
		// Copy the current listeners to avoid ConcurrentModificationExceptions
		// Usually triggered when a listener is added while notifying the listeners
		@SuppressWarnings("unchecked")
		ArrayList<IServiceListener> listenersCopy = (ArrayList <IServiceListener>) this.listeners.clone();
		for(IServiceListener listener : listenersCopy){
			try {
				listener.update();
			} catch (Exception e) {
				//e.printStackTrace();
				logger.error(" Error while updating service: " + listener.toString());
			}
		} 
	}
}