#Design pattern examples

1 Observer
2 Startegy - for changing the behavior at run time.
3 Decorator - coffee example
4 Decorator2 - gui component example
5 FactoryMethod - Car example
6 AbstractFactory - Windows button example
(Main diff between FactoryMethod and AbstractFactory is that AbstractFactory is completely interface driven.)
7 Command - When similar kind of execution has to be done from a single place then use command pattern...Universal Remote control example
8 Command2 - Todo : Example on network crashing...it is using other patterns like singleton and observer.
9 Singleton - Threadsafe singleton needs double nullability check...."http://javarevisited.blogspot.in/2011/06/volatile-keyword-java-example-tutorial.html" explains the importance of volatile.
10 Adapter pattern - It is similar to Decorator where we wrap an object but the difference is in the intent.In Adapter pattern the intent is to make a class adapted to particular requirement.(Example of cat adapting to Lion interface)
11 Facade Pattern - It is similar to Adapter and Decorator but again the intent is different , Its job is to expose a simpler interface to the user hiding complex details...example is of starting a movie or programming over a computer.
12 Template method- Its nothing but interaction between abstract and concrete...No example 
13 Iterator -Main purpose of Iterator pattern is to iterate over collection without exposing its implementation.
14 Composite - The composite pattern is any tree kind of structure where from child another tree can start...For eg : the DOM is also a composite object...therefore from the body to the innermost divs and components we can create a composite object...TODO DOM example time and will permitting.
15 State pattern - Example of Delhi metro turnstile.