Singleton pattern in Java?

Anonymous User 2017 17 Jul 2015

What is an efficient way to implement a singleton pattern in Java?

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Updated 18 Jul 2015

1 Answers

Anonymous User 18 Jul 2015

Use an enum:

public enum Foo {
    INSTANCE;
}

public enum Elvis {
    INSTANCE;
    private final String[] favoriteSongs =
        { "Hound Dog", "Heartbreak Hotel" };
    public void printFavorites() {
        System.out.println(Arrays.toString(favoriteSongs));
    }
}

"This approach is functionally equivalent to the public field approach, except that it is more concise, provides the serialization machinery for free, and provides an ironclad guarantee against multiple instantiation, even in the face of sophisticated serialization or reflection attacks. While this approach has yet to be widely adopted, a single-element enum type is the best way to implement a singleton."

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Singleton pattern in Java?

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