Random Singleton in Java

RandomSingleton.java

public class RandomSingleton {
    private static RandomSingleton instance;
    private Random rnd;

    private RandomSingleton() {
        rnd = new Random();
    }

    public static RandomSingleton getInstance() {
        if(instance == null) {
            instance = new RandomSingleton();
        }
        return instance;
    }

    public double nextDouble() {
         return rnd.nextDouble();
    }
}