PHP 디자인 패턴: 팩토리 패턴

팩토리 패턴:

팩토리 클래스는 매개변수를 기반으로 생성할 제품 클래스의 인스턴스를 결정합니다.

팩토리 클래스는 다른 개체를 생성하는 데 특별히 사용되는 메서드를 포함한다는 의미입니다. 수업. 소위 주문형 할당은 선택을 위한 매개변수를 전달하고 특정 클래스를 반환하는 것입니다. 팩토리 패턴의 주요 기능은 객체 생성을 캡슐화하고 객체 생성 작업을 단순화하는 것입니다.

간단히 말하면 팩토리 클래스의 메소드를 호출하여(매개변수 전달) 필요한 클래스를 가져오는 것입니다.

코드 구현:

예제 1( 가장 기본적인 팩토리 클래스):

<?php
 
class MyObject {
 
public function __construct(){}
 
public function test(){
return &#39;测试&#39;;
}
 
}
 
class MyFactory {
 
public static function factory(){
//返回对象的实例
return new MyObject();
}
 
}
 
//调用工厂类MyFactory中的静态方法,获取类MyObject的实例
$myobject=MyFactory::factory();
echo $myobject->test();

예시 2:

<?php
//简单工厂模式
/1*
 * 定义运算类
 */
abstract class Operation {
 
protected $_NumberA = 0;
protected $_NumberB = 0;
protected $_Result  = 0;
 
public function __construct($A,$B){
$this->_NumberA = $A;
$this->_NumberB = $B;
}
 
public function setNumber($A,$B){
$this->_NumberA = $A;
$this->_NumberB = $B;
}
 
/1*
protected function clearResult(){
$this->_Result  = 0;
}
*/
 
public function clearResult(){
$this->_Result  = 0;
}
 
//抽象方法无方法体
abstract protected function getResult();
 
}
 
//继承一个抽象类的时候，子类必须实现抽象类中的所有抽象方法；
//另外，这些方法的可见性 必须和抽象类中一样（或者更为宽松）
class OperationAdd extends Operation {
 
public function getResult(){
$this->_Result=$this->_NumberA + $this->_NumberB;
return $this->_Result;
}
 
}
 
class OperationSub extends Operation {
 
public function getResult(){
$this->_Result=$this->_NumberA - $this->_NumberB;
return $this->_Result;
}
 
}
 
class OperationMul extends Operation {
 
public function getResult(){
$this->_Result=$this->_NumberA * $this->_NumberB;
return $this->_Result;
}
 
}
 
class OperationDiv extends Operation {
 
public function getResult(){
$this->_Result=$this->_NumberA / $this->_NumberB;
return $this->_Result;
}
 
}
 
class OperationFactory {
 
//创建保存实例的静态成员变量
private static $obj;
 
//创建访问实例的公共的静态方法
public static function CreateOperation($type,$A,$B){
switch($type){
case &#39;+&#39;:
self::$obj = new OperationAdd($A,$B);
break;
case &#39;-&#39;:
self::$obj = new OperationSub($A,$B);
break;
case &#39;*&#39;:
self::$obj = new OperationMul($A,$B);
break;
case &#39;/&#39;:
self::$obj = new OperationDiv($A,$B);
break;
}
return self::$obj;
}
 
}
 
//$obj = OperationFactory::CreateOperation(&#39;+&#39;);
//$obj->setNumber(4,4);
$obj = OperationFactory::CreateOperation(&#39;*&#39;,5,6);
echo $obj->getResult();
/1*
echo &#39;<br>&#39;;
$obj->clearResult();
echo &#39;<br>&#39;;
echo $obj->_Result;
*/

예 3:

<?php
//抽象工厂
 
//青铜会员的打折商品
class BronzeRebateCommodity {
//描述
public $desc = &#39;青铜会员的打折商品&#39;;
}
 
//白银会员的打折商品
class SilverRebateCommodity {
public $desc = &#39;白银会员的打折商品&#39;;
}
 
//青铜会员的推荐商品
class BronzeCommendatoryCommodity {
public $desc = &#39;青铜会员的推荐商品&#39;;
}
 
//白银会员的推荐商品
class SilverCommendatoryCommodity {
public $desc = &#39;白银会员的推荐商品&#39;;
}
 
//各个工厂的接口
interface ConcreteFactory {
//生产对象的方法
public function create($what);
}
 
//青铜工厂
class BronzeFactory implements ConcreteFactory {
 
//生产对象的方法
public function create($what){
$productName = &#39;Bronze&#39;.$what.&#39;Commodity&#39;;
return new $productName;
}
 
}
 
//白银工厂
class SilverFactory implements ConcreteFactory {
 
//生产对象的方法
public function create($what){
$productName = &#39;Silver&#39;.$what.&#39;Commodity&#39;;
return new $productName;
}
 
}
 
//调度中心
class CenterFactory {
 
//获取工厂的方法
public function getFactory($what){
$factoryName = $what.&#39;Factory&#39;;
return new $factoryName;
}
 
//获取工厂的静态方法
public static function getFactory2($what){
$factoryName = $what.&#39;Factory&#39;;
return new $factoryName;
}
 
}
 
//实例化调度中心
$center  = new CenterFactory();
//获得一个白银工厂
$factory = $center->getFactory(&#39;Silver&#39;);
//让白银工厂制造一个推荐商品
$product = $factory->create(&#39;Commendatory&#39;);
//得到白银会员的推荐商品
echo $product->desc.&#39;<br>&#39;;
 
//获得一个青铜工厂
$factory2 = CenterFactory::getFactory2(&#39;Bronze&#39;);
//让青铜工厂制造一个打折商品
$product2 = $factory2->create(&#39;Rebate&#39;);
//得到青铜会员的推荐商品
echo $product2->desc;

예 4:

<?php
//使用工厂类解析图像文件
interface IImage {
 
function getWidth();
function getHeight();
function getData();
 
}
 
class Image_PNG implements IImage {
 
protected $_width,$_height,$_data;
 
public function __construct($file){
$this->_file = $file;
$this->_parse();
}
 
private function _parse(){
//完成PNG格式的解析工作
//并填充$_width,$_height和$_data
$this->_data   = getimagesize($this->_file);
list($this->_width,$this->_height)=$this->_data;
}
 
public function getWidth(){
return $this->_width;
}
 
public function getHeight(){
return $this->_height;
}
 
public function getData(){
return $this->_data;
}
 
}
 
class Image_JPEG implements IImage {
 
protected $_width,$_height,$_data;
 
public function __construct($file){
$this->_file = $file;
$this->_parse();
}
 
private function _parse(){
//完成JPEG格式的解析工作
//并填充$_width,$_height和$_data
//$this->_width  = imagesx($this->_file);
//$this->_height = imagesy($this->_file);
$this->_data   = getimagesize($this->_file);
list($this->_width,$this->_height)=$this->_data;
}
 
public function getWidth(){
return $this->_width;
}
 
public function getHeight(){
return $this->_height;
}
 
public function getData(){
return $this->_data;
}
 
}
 
//工厂类
class ImageFactory {
 
public static function factory($file){
 
$filename = pathinfo($file);
switch(strtolower($filename[&#39;extension&#39;])){
case &#39;jpg&#39;:
$return = new Image_JPEG($file);
break;
case &#39;png&#39;:
$return = new Image_PNG($file);
break;
default:
echo &#39;图片类型不正确&#39;;
break;
}
if($return instanceof IImage){
return $return;
}else{
echo &#39;出错了&#39;;
exit();
}
 
}
 
}
 
$image = ImageFactory::factory(&#39;images/11.jpg&#39;);
var_dump($image->getWidth());
echo &#39;<br>&#39;;
print_r($image->getheight());
echo &#39;<br>&#39;;
print_r($image->getData());

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