《Head First 设计模式》代码之PHP版(面向对象学习)第1/2页

书中的例子都比较浅显易懂，不过由于是外国佬写的，所以例子的习惯不是很附合中国特色，可能偶尔看起来有些别扭，还有语言习惯也不是中国风。当然��看过这本书之后，你才能深刻理解设计模式到底能为你解决哪些问题，不能为你解决哪些问题（比如不能代替你的编码）。
　　我将书中部分代码改成php，看下代码再配合概念应该是比较容易理解了。

策略模式

<?php
/**
* 策略模式
* 定义了算法族，分别封装起来，让它们之间可以互相替换，
* 此模式让算法的变化独立于使用算法的客户。
*/
//飞行行为接口
interface flybehavior {
public function fly();
}
//呱呱叫行为接口
interface quackbehavior {
public function quack();
}
//翅膀飞行
class flywithwings implements flybehavior {
public function fly() {
echo "i'm flying!!\n";
}
}
//不会飞
class flynoway implements flybehavior {
public function fly() {
echo "i can't fly!\n";
}
}
class flyrocketpowered implements flybehavior {
public function fly() {
echo "i'm flying with a rocket!\n";
}
}
class qquack implements quackbehavior {
public function quack() {
echo "quack\n";
}
}
class squeak implements quackbehavior {
public function quack() {
echo "squeak\n";
}
}
class mutequack implements quackbehavior {
public function quack() {
echo "<< silence >>\n";
}
}
abstract class duck {
protected $quack_obj;
protected $fly_obj;
public abstract function display();

public function performquack() {
$this->quack_obj->quack();
}
public function performfly() {
$this->fly_obj->fly();
}
public function swim() {
echo "all ducks float, even decoys!\n";
}
public function setflybehavior(flybehavior $fb) {
$this->fly_obj = $fb;
}
public function setquackbehavior(quackbehavior $qb) {
$this->quack_obj = $qb;
}
}

class modelduck extends duck {
public function __construct() {
$this->fly_obj = new flynoway();
$this->quack_obj = new mutequack();
}
public function display() {
echo "i'm a model duck!\n";
}
}

$model = new modelduck();
$model->performfly();
$model->performquack();
//提供新的能力
$model->setflybehavior(new flyrocketpowered());
$model->setquackbehavior(new squeak());
$model->performfly();
$model->performquack();

?>

单件模式

<?php
/**
* 单件模式
* 确保一个类只有一个实例，并提供一个全局访问点。
*/
class myclass {
private static $uniqueinstance;
private function __construct() {

}
public static function getinstance() {
if (self::$uniqueinstance == null) {
self::$uniqueinstance = new myclass();
}
return self::$uniqueinstance;
}
}
$myclass = myclass::getinstance();
var_dump($myclass);
$myclass = myclass::getinstance();
var_dump($myclass);
?>

工厂方法模式

<?php
abstract class pizzastore {
public function orderpizza($type) {
$pizza = $this->createpizza($type);

$pizza->prepare();
$pizza->bake();
$pizza->cut();
$pizza->box();
return $pizza;
}

public abstract function createpizza($type);
}
class nypizzastore extends pizzastore {
public function createpizza($type) {
if ($type == "cheese") {
return new nystylecheesepizza();
} elseif ($type == "veggie") {
return new nystyleveggiepizza();
} elseif ($type == "clam") {
return new nystyleclampizza();
} elseif ($type == "papperoni") {
return new nystylepapperonipizza();
} else {
return null;

}
}
}
class chicagopizzastore extends pizzastore {
public function createpizza($type) {
if ($type == "cheese") {
return new chicagostylecheesepizza();
} elseif ($type == "veggie") {
return new chicagostyleveggiepizza();
} elseif ($type == "clam") {
return new chicagostyleclampizza();
} elseif ($type == "papperoni") {
return new chicagostylepapperonipizza();
} else {
return null;
}
}
}
abstract class pizza {
public $name;
public $dough;
public $sauce;
public $toppings = array();

public function prepare() {
echo "preparing " . $this->name . "\n";
echo "yossing dough...\n";
echo "adding sauce...\n";
echo "adding toppings: \n";
for ($i = 0; $i < count($this->toppings); $i++) {
echo " " . $this->toppings[$i] . "\n";
}
}

public function bake() {
echo "bake for 25 minutes at 350\n";
}

public function cut() {
echo "cutting the pizza into diagonal slices\n";
}

public function box() {
echo "place pizza in official pizzastore box\n";
}

public function getname() {
return $this->name;
}
}

class nystylecheesepizza extends pizza {
public function __construct() {
$this->name = "ny style sauce and cheese pizza";
$this->dough = "thin crust dough";
$this->sauce = "marinara sauce";

$this->toppings[] = "grated reggiano cheese";
}
}

class nystyleveggiepizza extends pizza {
public function __construct() {
$this->name = "ny style sauce and veggie pizza";
$this->dough = "thin crust dough";
$this->sauce = "marinara sauce";

$this->toppings[] = "grated reggiano veggie";
}
}
class nystyleclampizza extends pizza {
public function __construct() {
$this->name = "ny style sauce and clam pizza";
$this->dough = "thin crust dough";
$this->sauce = "marinara sauce";

$this->toppings[] = "grated reggiano clam";
}
}
class nystylepapperonipizza extends pizza {
public function __construct() {
$this->name = "ny style sauce and papperoni pizza";
$this->dough = "thin crust dough";
$this->sauce = "marinara sauce";

$this->toppings[] = "grated reggiano papperoni";
}
}

class chicagostylecheesepizza extends pizza {
public function __construct() {
$this->name = "chicago style deep dish cheese pizza";
$this->dough = "extra thick crust dough";
$this->sauce = "plum tomato sauce";

$this->toppings[] = "shredded mozzarella cheese";
}

public function cut() {
echo "cutting the pizza into square slices\n";
}
}

$mystore = new nypizzastore();
$chicagostore = new chicagopizzastore();
$pizza = $mystore->orderpizza("cheese");
echo "ethan ordered a " . $pizza->getname() . "\n";

$pizza = $chicagostore->orderpizza("cheese");
echo "ethan ordered a " . $pizza->getname() . "\n";

?>

工厂模式

<?php
abstract class pizzastore {
public function orderpizza($type) {
$pizza = $this->createpizza($type);

$pizza->prepare();
$pizza->bake();
$pizza->cut();
$pizza->box();
return $pizza;
}

public abstract function createpizza($type);
}
class nypizzastore extends pizzastore {
public function createpizza($type) {
$pizza = null;
$ingredientfactory = new nypizzaingredientfactory();
if ($type == "cheese") {
$pizza = new cheesepizza($ingredientfactory);
$pizza->setname('new york style cheese pizza');
} elseif ($type == "veggie") {
$pizza = new veggiepizza($ingredientfactory);
$pizza->setname('new york style veggie pizza');
} elseif ($type == "clam") {
$pizza = new clampizza($ingredientfactory);
$pizza->setname('new york style clam pizza');
} elseif ($type == "papperoni") {
$pizza = new papperonipizza($ingredientfactory);
$pizza->setname('new york style papperoni pizza');
}
return $pizza;
}
}
class chicagopizzastore extends pizzastore {
public function createpizza($type) {
if ($type == "cheese") {
return new chicagostylecheesepizza();
} elseif ($type == "veggie") {
return new chicagostyleveggiepizza();
} elseif ($type == "clam") {
return new chicagostyleclampizza();
} elseif ($type == "papperoni") {
return new chicagostylepapperonipizza();
} else {
return null;
}
}
}
interface pizzaingredientfactory {
public function createdough();
public function createsauce();
public function createcheese();
public function createveggies();
public function createpepperoni();
public function createclam();
}
class nypizzaingredientfactory implements pizzaingredientfactory {
public function createdough() {
return new thincrustdough();
}
public function createsauce() {
return new marinarasauce();
}
public function createcheese() {
return new reggianocheese();
}
public function createveggies() {
$veggies = array(
new garlic(),
new onion(),
new mushroom(),
new redpepper(),
);
return $veggies;
}
public function createpepperoni() {
return new slicedpepperoni();
}
public function createclam() {
return new freshclams();
}
}
class chicagopizzaingredientfactory implements pizzaingredientfactory {
public function createdough() {
return new thickcrustdough();
}
public function createsauce() {
return new plumtomatosauce();
}
public function createcheese() {
return new mozzarella();
}
public function createveggies() {
$veggies = array(
new blackolives(),
new spinach(),
new eggplant(),
);
return $veggies;
}
public function createpepperoni() {
return new slicedpepperoni();
}
public function createclam() {
return new frozenclams();
}
}
abstract class pizza {
public $name;
public $dough;
public $sauce;
public $veggies = array();
public $cheese;
public $pepperoni;
public $clam;

public abstract function prepare();

public function bake() {
echo "bake for 25 minutes at 350\n";
}

public function cut() {
echo "cutting the pizza into diagonal slices\n";
}

public function box() {
echo "place pizza in official pizzastore box\n";
}

public function getname() {
return $this->name;
}

public function setname($name) {
$this->name = $name;
}

public function __tostring() {

}
}

class cheesepizza extends pizza {
public $ingredientfactory;

public function __construct(pizzaingredientfactory $ingredientfactory) {
$this->ingredientfactory = $ingredientfactory;
}

public function prepare() {
echo "preparing " . $this->name . "\n";
$this->dough = $this->ingredientfactory->createdough();
$this->sauce = $this->ingredientfactory->createsauce();
$this->cheese = $this->ingredientfactory->createcheese();
}
}

class clampizza extends pizza {
public $ingredientfactory;

public function __construct(pizzaingredientfactory $ingredientfactory) {
$this->ingredientfactory = $ingredientfactory;
}

public function prepare() {
echo "preparing " . $this->name . "\n";
$this->dough = $this->ingredientfactory->createdough();
$this->sauce = $this->ingredientfactory->createsauce();
$this->cheese = $this->ingredientfactory->createcheese();
$clam = $this->ingredientfactory->createclam();
}
}

$nypizzastore = new nypizzastore();
$nypizzastore->orderpizza('cheese');
?>

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