命令行模式（Command）

模式架构简单代码实现示例：

<?php
interface Command { // 命令角色
    public function execute(); // 执行方法
}
class ConcreteCommand implements Command { // 具体命令方法 
    private $_receiver; 
    public function __construct(Receiver $receiver) {
        $this->_receiver = $receiver;
    }
    public function execute() {
        $this->_receiver->action();
    }
}
class Receiver { // 接收者角色
    private $_name;
    public function __construct($name) {
        $this->_name = $name;
    }
    public function action() {
        echo 'receive some cmd:'.$this->_name;
    }
}
class Invoker { // 请求者角色
    private $_command; 
    public function __construct(Command $command) {
        $this->_command = $command;
    }
    public function action() {
        $this->_command->execute();
    }
}

$receiver = new Receiver('hello world');
$command = new ConcreteCommand($receiver);
$invoker = new Invoker($command);
$invoker->action();
?>