单例设计模式

单例设计模式

单例模式分为懒汉式和饿汉式

1.饿汉式

代码实现：

public class Test {
    public static void main(String[] args) {
        Single single = Single.getSingle();
    }
}
class Single{
    private Single(){}
    private static Single s = new Single();
    public static Single getSingle(){
        return s;
    }
}

2.懒汉式

代码实现：

public class Test {
    public static void main(String[] args) {
        Single single = Single.getSingle();
    }
}
class Single{
    private Single(){}
    private static Single s ;
    public static Single getSingle(){
        if(s==null){
           s = new Single();            
        }
        return s;
    }
}