设计模式-命令模式
0x00 命令模式定义
命令模式是一个高内聚的模式，其定义为: Encapsulate a request as an object, there by letting you parameterize clients with different requests, queue or log requests, and support undoable oerations.
(将一个请求封装成一个对象，从而让你使用不同的请求把客户端参数化，对请求队列或者记录请求日志，可以提供命令的撤销和回复功能。)
Receive 接受这角色, 命令传递到这里被执行。
Command 命令角色, 声明需要执行的所有命令。
Invoker 调用者角色, 接受到命令，并执行命令。
php 实现1
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<?php
/*
command pattern
*/
// 通用的 Receiver 类
abstract class Receiver {
abstract function dosth();
}
// 具体的 Receiver 类
class ConcreteReceiver1 extends Receiver {
public function doSth() {
}
}
class ConcreteReceiver2 extends Receiver {
public function doSth() {
}
}
// 抽象的Command 类
abstract class Command {
abstract function execute();
}
// 具体 Command 类
class ConcreteCommand1 extends Command {
private $receiver;
public function ConcreteCommand1(Receiver $_receiver) {
$this->receiver = $_receiver;
}
public function execute() {
$this->receiver->doSth();
}
}
class ConcreteCommand2 extends Command {
private $receiver;
public function ConcreteCommand2(Receiver $_receiver) {
$this->receiver = $_receiver;
}
public function execute() {
$this->receiver->doSth();
}
}
// 调用者 Invoker 类
class Invoker {
private $command;
public function setCommand(Command $_command) {
$this->command = $_command;
}
public function act() {
$this->command->execute();
}
}
// 场景调用
class client {
public static function main() {
$invoker = new Invoker();
$receiver = new ConcreteReceiver1();
$command = new ConcreteCommand1($receiver);
$invoker->setCommand($command);
$invoker->act();
}
}