第七天

单态模式;

class Demo{ public static void main(String[] args) { Singleton singleton = Singleton.getInstance(); singleton.print();}}class Singleton{private static Singleton instance = new Singleton();public static Singleton getInstance() {return instance;}public static void setInstance(Singleton instance) {Singleton.instance = instance;}private Singleton(){}public void print(){System.out.println("xym");}

}