Java中的单例设计模式举例

class Singleton
{
    static Singleton instance = new Singleton();
    private Singleton()
    {

    }

    public static Singleton getInstance()
    {
        return Singleton.instance;
    }


    public void func()
    {
        System.out.println("Hi there, this is a singleton demo.");
    }
}

public class  Hello
{ 
    public static void main(String[] args) 
    { 
        Singleton ins_1 = Singleton.getInstance();
        Singleton ins_2 = Singleton.getInstance();
        Singleton ins_3 = Singleton.getInstance();


        ins_1.func();
        ins_2.func();
        ins_3.func();
    } 
}