Java基础多线程之单例模式之懒汉式：

class SingleDemo
{
    public static void main(String[] args)
    {
        for(int i=1;i<10;i++)
        {
            Thread t1 = new Test();
            t1.start();
        }
    }
}

class Test extends Thread
{
    public void run()
    {
        Single single = Single.getInstance();
        System.out.println(this.getName() + " getInstance:"+single);
    }
}

class Single
{
    private static Single single = null;
    
    private Single(){}
    
    public static Single getInstance()
    {
        if(null==single)
        {
            synchronized(Single.class)
            {
                if(null==single)
                    single = new Single();
            }
        }
        
        return single;
    }
}