单列模式

 

package com.cvicse.daofactory;
public class SingleSpoon {
    private static SingleSpoon instance;
    private SingleSpoon(){
        //内部可以做一些初始化成员变量的操作
    }
    public static synchronized SingleSpoon getInstance(){
         if (instance == null) {
               instance = new SingleSpoon();
           }
           return instance;
    }
}