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";