Java设计模式之单例模式

//饿汉式
public class SingleTon {

    private SingleTon(){

    }

    private static SingleTon singleTon = new SingleTon();

    public  static SingleTon getInstance(){
        return singleTon;
    }


}

=========================================================

//懒汉式，可能存在线程安全问题
public class SingleTon1 {

    private SingleTon1(){

    }

    private static SingleTon1 singleTon = null;

    public  static SingleTon1 getInstance(){
        if (singleTon == null) {
            singleTon = new SingleTon1();
        }

        return singleTon;
    }


}

详细设计模式讲解请前往：https://blog.csdn.net/zhangerqing/article/details/8194653