class Singleton{
private Singleton(){
}
private static volatile Singleton singleton = null;
public static Singleton getInstance(){
if (singleton == null){
synchronized (Singleton.class){
if (singleton == null){
singleton = new Singleton();
}
}
}
return singleton;
}
}
标签：Singleton,singleton,private,static,模式,单例,null From： https://www.cnblogs.com/jixian/p/17175698.html