public class Singleton{
private volatile static Singleton singleton;
private Singleton(){};
public static Singleton getInstance(){
if(null == singleton){
synchronized(Singleton.class){
if(null == singleton){
singleton = new Singleton ();
}
}
}
}
}
不延遲初始化
public class Singleton{
private static Singleton singleton = new Singleton();
public Singleton(){};
public static getInstance(){
return singleton ;
}
}