PHP常用设计模式汇总
装饰模式:
<?php abstract class Tile { abstract function getWealthFactor(); } class Plains extends Tile { private $wealthfactor = 2; function getWealthFactor() { return $this->wealthfactor; } } abstract class TileDecorator extends Tile { // 装饰 protected $tile; function __construct( Tile $tile ) { $this->tile = $tile; } } class DiamondDecorator extends TileDecorator { // 钻石装饰 function getWealthFactor() { return $this->tile->getWealthFactor()+2; } } class PollutionDecorator extends TileDecorator { // 污染装饰 function getWealthFactor() { return $this->tile->getWealthFactor()-4; } } $tile = new Plains(); print $tile->getWealthFactor(); // 2 $tile = new DiamondDecorator( new Plains()); print $tile->getWealthFactor(); // 4 $tile = new PollutionDecorator( new DiamondDecorator( new Plains())); print $tile->getWealthFactor(); // 0 ?>
组合模式:
<?php abstract class Unit { abstract function bombardStrength(); } class Archer extends Unit { function bombardStrength() { return 4; } } class LaserCannonUnit extends Unit { function bombardStrength() { return 44; } } class Army { private $units = array(); private $armies= array(); function addUnit( Unit $unit ) { array_push( $this->units, $unit ); } function addArmy( Army $army ) { array_push( $this->armies, $army ); } function bombardStrength() { $ret = 0; foreach( $this->units as $unit ) { $ret += $unit->bombardStrength(); } foreach( $this->armies as $army ) { $ret += $army->bombardStrength(); } return $ret; } } $unit1 = new Archer(); $unit2 = new LaserCannonUnit(); $army = new Army(); $army->addUnit( $unit1 ); $army->addUnit( $unit2 ); print $army->bombardStrength(); print "\n"; $army2 = clone $army; // 克隆军队 $army->addArmy( $army2 ); print $army->bombardStrength(); print "\n"; ?>
工厂模式
<?php /** * 操作类 * 因为包含有抽象方法,所以类必须声明为抽象类 */ abstract class Operation{ //抽象方法不能包含函数体 abstract public function getValue($num1,$num2);//强烈要求子类必须实现该功能函数 } /** * 加法类 */ class OperationAdd extends Operation { public function getValue($num1,$num2){ return $num1+$num2; } } /** * 减法类 */ class OperationSub extends Operation { public function getValue($num1,$num2){ return $num1-$num2; } } /** * 乘法类 */ class OperationMul extends Operation { public function getValue($num1,$num2){ return $num1*$num2; } } /** * 除法类 */ class OperationDiv extends Operation { public function getValue($num1,$num2){ try { if ($num2==0){ throw new Exception("除数不能为0"); }else { return $num1/$num2; } }catch (Exception $e){ echo "错误信息:".$e->getMessage(); } } /** * 工厂类,主要用来创建对象 * 功能:根据输入的运算符号,工厂就能实例化出合适的对象 * */ class Factory{ public static function createObj($operate){ switch ($operate){ case '+': return new OperationAdd(); break; case '-': return new OperationSub(); break; case '*': return new OperationSub(); break; case '/': return new OperationDiv(); break; } } } $test=Factory::createObj('/'); $result=$test->getValue(23,0); echo $result; ?>
单例模式
<?php /** * Singleton of Database */ class Database { // We need a static private variable to store a Database instance. privatestatic $instance; // Mark as private to prevent it from being instanced. private function__construct() { // Do nothing. } private function__clone() { // Do nothing. } public static function getInstance() { if (!(self::$instanceinstanceofself)) { self::$instance = newself(); } returnself::$instance; } } $a =Database::getInstance(); $b =Database::getInstance(); // true var_dump($a === $b);
策略模式
<?php interface FlyBehavior{ public function fly(); } class FlyWithWings implements FlyBehavior{ public function fly(){ echo "Fly With Wings \n"; } } class FlyWithNo implements FlyBehavior{ public function fly(){ echo "Fly With No Wings \n"; } } class Duck{ private $_flyBehavior; public function performFly(){ $this->_flyBehavior->fly(); } public function setFlyBehavior(FlyBehavior $behavior){ $this->_flyBehavior = $behavior; } } class RubberDuck extends Duck{ } // Test Case $duck = new RubberDuck(); /* 想让鸭子用翅膀飞行 */ $duck->setFlyBehavior(new FlyWithWings()); $duck->performFly(); /* 想让鸭子不用翅膀飞行 */ $duck->setFlyBehavior(new FlyWithNo()); $duck->performFly(); ?>
适配器模式
class User { private $name; function __construct($name) { $this->name = $name; } public function getName() { return $this->name; } } //新代码,开放平台标准接口 interface UserInterface { function getUserName(); } class UserInfo implements UserInterface { protected $user; function __construct($user) { $this->user = $user; } public function getUserName() { return $this->user->getName(); } } $olduser = new User('张三'); echo $olduser->getName()."n"; $newuser = new UserInfo($olduser); echo $newuser->getUserName()."n";