#使用工厂方法模式是不知道要创建类的对象有哪些.
interface IFactory
{
public function CreateOperation();#工厂方法模式只有单个产品
}
class Operation extends Model
{
private $numberA;
private $numberB;
public function getResult(){
$result = 0;
return $result;
}
public function getNumberA(){
return $this->numberA;
}
public function setNumberA($numberA){
$this->numberA = $numberA;
}
public function getNumberB(){
return $this->numberB;
}
public function setNumberB($numberB){
$this->numberB = $numberB;
}
}
class OperationAdd extends Operation
{
public function getResult()
{
$result = 0 ;
$result = $this->numberA + $this->numberB;
return $result;
}
}
class OperationSub extends Operation
{
public function getResult()
{
$result = 0;
$result = $this->numberA - $this->numberB;
return $result;
}
}
class OperationMul extends Operation
{
public function getResult(){
$result = 0;
$result = $this->numberA * $this->numberB;
return $result;
}
}
class OperationDiv extends Operation
{
public function getResult(){
$result = 0;
if ($this->numberA == 0){
throw new HttpException("除数不能为0");
}
$result = $this->numberA / $this->numberB;
return $result;
}
}
class AddFactory implements IFactory
{
public function CreateOperation()
{
return new OperationAdd();
}
}
class SubFactory implements IFactory
{
public function CreateOperation()
{
return new OperationSub();
}
}
class MulFactory implements IFactory
{
public function CreateOperation()
{
return new OperationMul();
}
}
class DivFactory implements IFactory
{
public function CreateOperation()
{
return new OperationDiv();
}
}
$operFactory = new AddFactory();
$oper = $operFactory->CreateOperation();
$oper->numberA = 1;
$oper->numberB = 2;
$result = $oper->getResult();
echo $result;
简单工厂和工厂方法的区别:简单工厂模式的最大优点在于工厂类中包含了必要的逻辑判断,根据客户端的选择条件动态实例化相关的类，但是如果要添加新的功能,就要修改里面的case条件修改原有的类，这样违背了开放-封闭原则。工厂方法模式,定义一个用于创建对象的接口,让子类决定实例化
那个类。工厂方法使一个类的实例化延迟到其子类。
工厂方法模式实现时,客户端需要决定实例化那一个工厂来实现运算类，选择判断的问题还是存在的,也就是说,工厂方法把简单工厂的内部逻辑判断移到了客户端代码来进行
