LazySingleton

package 设计模式八大考题.单例模式;

public class LazySingletonDemo {
    //懒汉式之不加锁 synchronized          线程不安全


     private LazySingletonDemo instance;
     private LazySingletonDemo (){

     }
     public LazySingletonDemo getInstance() {
             if (instance == null) {
                     instance = new LazySingletonDemo();
             }
             return instance;
     }
}