饿汉式单例 public class Singleton { private Singleton(){} private static Singleton instance = new Singleton(); public static Singleton getInstance(){ return instance; } } 懒汉式单例 public class Singleton { private static Singleton instance = null; private Sin
<?php class User { //静态变量保存全局变量 private static $_instance=null; //私有化构造函数,防止外界实例化对象 private function __construct() { } //私有化克隆,防止外界克隆对象 private function __clone(){ } //静态方法,单例统一访问接口 static public function getInstance(){ if(is_null(self::$_instance)||
首先写个单例,懒汉模式: public class SingleDemo { private static SingleDemo s = null; private SingleDemo(){} public static SingleDemo getInstance(){ if(s == null){ s = new SingleDemo(); } return s; } } 写个测试类: public class ThreadDemo3 { public static void main(S