singleton.java

金旭亮的java教案

public class Singleton
{
	public static void main(String[] args)
	{
		A a1,a2;
		a1=A.getInstance();
		a2=A.getInstance();
		System.out.println(a1==a2);
		
	}
}

class A
{
	private static A a;
	private A()
	{
		
	}
	public static  A getInstance()
	{
		if(a==null)
			a= new A();
		
			return a;
	}
}