单例模式之JAVA实现

class Singleton {
    private static Singleton instance = null;
    private Singleton()
    {
        System.out.println("Init the Singleton instance!");
    }
    public static Singleton getInstance() {
        if (null == instance)
            instance = new Singleton();
        return instance;
    }
}

public class SingletonPattern {
    /**
     * @param args
     */
    public static void main(String[] args) {
        Singleton instanceA = Singleton.getInstance();
        Singleton instanceB = Singleton.getInstance();
        
        if (instanceA == instanceB) {
            System.out.println("They are the same instance!");
        }
    }

}