Singleton class is a class which ensures that there is only one instance of the class is available throughout the JVM. It is know as Singleton class.
There are three characteristics of a Singleton class
1.Define a private constructor.
2. Define private and static instance
3. Define public and static method for the instance which allow access to instance.
/**
* singleton class ensures that there is
* only one instance of the class is available inside the jvm
*/
public class Singleton {
//characteristic of the singleton class
//1. private constructor so that no one can create object
private Singleton() {
}
//2. static instance
private static Singleton instance;
//3. static method for access
public static Singleton getInstance() {
if (instance == null) {
instance = new Singleton();
}
return instance;
}
}