Design patterns - Observer Pattern

Observer Pattern in Real LifeThere is always a Observer and Observable object around you.You are an Observer, TV is an Observable Object.-----------------------------------Ideology of Observer Pattern is something close.-----------------------------------Colloquially Observers are called as Listeners Observables are called as Providers Observable Observer Copyright 2006-2011

How Observer Pattern works in Real Life ? 1 Register/ Attach (When he wants to watch TV) DeRegister/ DeAttach (When he wants to not Watch TV) Observable Observer 2 Notify (When someone is Watching TV) 3 Observable Observer Copyright 2006-2011

How Observer Pattern works in Java ? public void changeChannel(String channelName) { public static void main(String[] args) { this.channelName = channelName; //Initialise Observable setChanged(); Television tv = new Television("Star Plus"); this.notifyObservers(); } 2 //Initialise Observer TelevisionViewer tViewer = new TelevisionViewer(); //Register Observer to Observable 31 tv.addObserver(tViewer); //Change TV Channel tv.changeChannel("STAR CRICKET"); } public void update(Observable arg0, Object arg1) { System.out.println("Channel Changed”); } Copyright 2006-2011

Design patterns - Observer Pattern

by Annamalai C on Mar 23, 2012

Accessibility

Categories

Upload Details

Usage Rights

Statistics

Design patterns - Observer Pattern Presentation Transcript