Java Singleton – enum implementation Singleton as enum is very simple to implement and very safe at the same time thanks to language guarantees for enum instantiation and serialization.

Java Singleton – on demand initialization On demand initialization is extension of static final implementation. It will prevent eager initialization of the singleton instance, when other fields are accessed. Also known as Bill Pugh‘s solution.

Java Singleton – static final implementation It is the simplest and most common implementation of Singleton Design Pattern in Java. In this post we’ll show how to implement it correctly and explain why it works.