设计模式之 策略模式

<?php
/*
 *抽象策略类 
 */
abstract class Stratrgy{
    abstract function AlgorithmInterface();
}

//具体实现类A
class ConcreateStratrgyA extends Stratrgy{
    public function AlgorithmInterface() {
        echo '算法A', PHP_EOL;
    }
}

//具体实现类B
class ConcreateStratrgyB extends Stratrgy{
    public function AlgorithmInterface() {
        echo '算法B', PHP_EOL;
    }
}

//具体实现类C
class ConcreateStratrgyC extends Stratrgy{
    public function AlgorithmInterface() {
        echo '算法C', PHP_EOL;
    }
}

//上下文环境类
class Context{
    private $_strategy;
    //通过构造方法注入策略对像
    public function __construct(Stratrgy $strategy) {
        $this->_strategy = $strategy;
    }
    public function ContextInterface(){
        $this->_strategy->AlgorithmInterface();
    }
}

//客户端类
class Client{
    public static function main(){
        $context = new Context(new ConcreateStratrgyA());
        $context->ContextInterface();
        
        $context = new Context(new ConcreateStratrgyB());
        $context->ContextInterface();
        
        $context = new Context(new ConcreateStratrgyC());
        $context->ContextInterface();
    }
}
Client::main();

<?php
//抽象策略类
abstract class StrategyNotify{
   //参数检查
   abstract function checkParam();
   //发送道具
   abstract function sendProp();
   //输出报文
   abstract function outputMessage();
   //支付回调状态
   protected $_status = -1;
   //第三方参数
   protected $_params = array();

   protected $_errMsg = array(
       '-1'=>'系统错误',
       '-2'=>'参数验证错误',
       '-3'=>'发送道具失败',
   );
   //通知方法
   public final function notify(){
       if(!$this->checkParam()){
           $this->_status = -2;
       }else if(!$this->sendProp()){
           $this->_status = -3;
       }else{
           $this->_status = 1;
       }
       if($this->_status != 1){
           $this->log();
       }
       $this->outputMessage();
   }
   //写日志例子
   protected function log(){
       echo isset($this->_errMsg[$this->_status]) ? $this->_errMsg[$this->_status] : '';
       echo PHP_EOL;
   }
}

//微信支付
class Weixin extends StrategyNotify{
   public function checkParam() {
       return false;
   }

   public function outputMessage() {
       if($this->_status === 1){
           die('OK');
       }else{
           die('FAIL');
       }
   }

   public function sendProp() {
       return false;
   }
}

//支付环境类
class Pay{
    private static $_notify = null;
    //策略工厂
    public static function factory($notify){
        if(class_exists($notify) && self::$_notify == null){
            self::$_notify = new $notify();
        }
        return self::$_notify;
    }
}

Pay::factory('Weixin')->notify();