enums - The best singleton pattern since Java 5

Question

Since Java 5 it is said that the best way to create a singleton is by a single-element enum type.

Example:

public enum SuperSingleton implements Zooma{
    INSTANCE;

    /**
     */
    public void fightTheBattle(){
        System.out.println("I am fighting the battle!!!");
    }

    @Override
    public void runningWild() {
        //This is method implemented from the Zooma interface.      
    }
}

According to Joshua Bloch, the single-element enum type singleton is;

• more concise
• provides the serialization machinery for free
• and provides an ironclad against multiple instantiation.

I can see how it is more concise and how it provides an ironclad against multiple instantiation, but how does it provide the serialization machinery for free?

Is it something the singleton gets by being an enum?

Answer 1

Yes, Enums are all extended off of the Enum class, which implements Serializable.