PHP设计模式中的命令模式

<?php
// 抽象命令类
abstract class Command
{
    protected $receiver;
    public function __construct(Receiver $receiver)
    {
        $this->receiver = $receiver;
    }
    abstract public function execute();
}
// 具体命令类A
class ConcreteCommandA extends Command
{
    public function execute()
    {
        $this->receiver->actionA();
    }
}
// 具体命令类B
class ConcreteCommandB extends Command
{
    public function execute()
    {
        $this->receiver->actionB();
    }
}
// 接收者类
class Receiver
{
    public function actionA()
    {
        echo "Receiver executes actionA.\n";
    }
    public function actionB()
    {
        echo "Receiver executes actionB.\n";
    }
}
// 客户端代码
$receiver = new Receiver();
$commandA = new ConcreteCommandA($receiver);
$commandB = new ConcreteCommandB($receiver);
$commandA->execute();
$commandB->execute();

<?php
$receiver = new Receiver();
$commandA = new ConcreteCommandA($receiver);
$commandB = new ConcreteCommandB($receiver);
$commandA->execute();
$commandB->execute();