为什么80%的码农都做不了架构师？>>> 
public class Singleton {private static Singleton instance = null;// 同步时加锁的静态对象private static final Object OL = new Object();private Singleton() {// Class initialize}/** 在多线程环境下执行时的双重检查Double Check*/public static Singleton getSynchronizedInstance() {if (instance == null) {synchronized (OL) {if (instance == null) {instance = new Singleton();}}}return instance;}/** 在非多线程环境下使用*/public static Singleton getInstance() {if (instance == null) {instance = new Singleton();}return instance;}/** 静态内部类的实例与外部类的实例没有绑定关系，只有其被调用到才会装载，从而实现延迟加载*/public static class Creator {// 静态域对象初始化，由JVM来保证线程安全private static Singleton singleton= new Singleton();}public static Singleton getStaticInstance() {return Creator.singleton;}
}
