Singleton is pretty simple. If you want only one instance of a class to exist at any one time, you use the Singleton pattern. The trick is to make the constructor private and add a static instance() method. The instance() method would check to see if an instance already exists...
if it doesn't it creates one, stores the pointer to it in a static variable, and returns the pointer.
If it does exist, it returns the pointer.
<pre>
public class SingletonSample {
private static SingletonSample singletonSample = null;
private SingletonSample() {}
public static SingletonSample instance() {
if (singletonSample == null)
singletonSample = new SingletonSample();
return singletonSample;
}
}
</pre>
