设计模式---单例模式

package 学习;
class Sing{
private static Sing sing=new Sing();
private Sing(){

}
public static   Sing getsing(){
return sing;
}

}
public class Tb {

public static void main(String[] args) {
// TODO 自动生成方法存根
Sing sing =Sing.getsing();

Sing sings =Sing.getsing();
System.out.println(sing==sings);
}

}