IoDH 实现的单例模式

Posted 2020-08-10 woqiaoxun

饿汉式单例类不能实现延迟加载，不管将来用不用始终占据内存；懒汉式单例类线程安全控制烦琐，而且性能受影响。有种更好的单例模式叫做Initialization Demand Holder (IoDH)的技术。

 

public class Singleton {

    private Singleton(){
        System.out.println(Singleton.class);
    }
    
    private static class HolderClass{
        private final static Singleton s = new Singleton();
    }
    
    public static Singleton getInstance(){
        return HolderClass.s;
    }
    
    
    public static void main(String[] args) {
        Singleton s = Singleton.getInstance();
    }
    
}