PHP设计模式应用实例（多态模式，工厂模式，命令模式）
1、多态模式
<?
class pub {
protected function working() {
echo '这是一个可以重写的方法';
}
}
class student extends pub {
public function working() {
echo '学生在学习';
}
}
class teacher extends pub {
public function working() {
echo '老师在讲课';
}
}
public function doing($obj) {
if ($obj instanceof pub) {
$obj->working();
} else {
echo '没有这个对象！';
}
}
doing(new student());
doing(new teacher());
?>
2、工厂模式：根据传入的类型名实例化对象，只负责生成对象，而不负责对象的具体内容
//定义一个适配器接口
interface Db_Adapter{
public function connect();
public function query();
}
//定义MySQL数据库操作类
class Db_Adapter_Mysql implements Db_Adapter{
public function connect(){
echo "mysql数据库连接操作";
}
public function query(){
echo "mysql数据库查询操作";
}
}
//定义SQLite数据库操作类
class Db_Adapter_Sqlite implements Db_Adapter{
public function connect(){
echo "sqlite数据库连接操作";
}
public function query(){
echo "sqlite数据库查询操作";
}
}
//定义工厂类
class sqlFactory{
public static function factory($type) {
$classname = 'Db_Adapter_'.$type;
return new $classname;
}
}
//调用
$db = sqlFactory::factory('Mysql');
$db = sqlFactory::factory('Sqlite');
3、命令模式
//定义厨师类，命令接受者与执行者
class cook{
public function meal() {
echo "西红柿炒鸡蛋<br>";
}
public function drink() {
echo "紫菜蛋花汤<br>";
}
public function ok() {
echo "完成<br>";
}
}
//命令接口
interface command{
public function execute();
}
//模拟服务员与厨师的过程
class mealCommand implements command{
private $cook;
public function __construct($cook){
$this->cook = $cook;
}
public function execute(){
$this->cook->meal();
}
}
class drinkCommand implements command{
private $cook;
public function __construct($cook){
$this->cook = $cook;
}
public function execute(){
$this->cook->drink();
}
}
//模拟顾客与服务员的过程
class cookControl{
private $mealCommand;
private $drinkCommand;
public function addCommond($mealCommand,$drinkCommand) {
$this->mealCommand = $mealCommand;
$this->drinkCommand = $drinkCommand;
}
public function callMeal(){
$this->mealCommand->execute();
}
public function callDrink(){
$this->drinkCommand->execute();
}
}
//实现命令模式
$cookControl = new cookControl();
$cook = new cook();
$mealCommand = new mealCommand($cook);
$drinkCommand = new drinkCommand($cook);
$cookControl->addCommond($mealCommand,$drinkCommand);
$cookControl->callMeal();
$cookControl->callDrink();
