1. 解析器模式//解析器内容类//用于存放表达式的运算结果,并且能根据传入的表达式返回当初记录的结果class InterpreterContext{ private $expressionstore=array(); //将对象放进array里面,索引号是对象ID号 function replace(Expression $exp,$value){ $this->expressionstore[$exp->getKey()]=$value; } function lookup(Expression $exp){ return $this->expressionstore[$exp->getKey()]; }}abstract class Expression{ private static $keyCount=0; private $key; abstract function interpret(InterpreterContext $context); //每一个对象都有一个唯一的key function getKey(){ if(!isset($this->key)){ $this->key=++self::$keyCount; } return $this->key; }}//字符串class LiteralExpression extends Expression{ private $value; function __construct($value){ $this->value=$value; } function interpret(InterpreterContext $context){ $context->replace($this, $this->value); }}//变量class VariableExpression extends Expression{ private $value; private $name; function __construct($name,$value=null){ $this->name=$name; $this->value=$value; } function setValue($value){ $this->value=$value; } function getKey(){ return $this->name; } function interpret(InterpreterContext $context){ if(!is_null($this->value)){ $context->replace($this, $this->value); //设置为空,可以避免在没有修改value的情况下再次调用该方法的时候, //也第二次调用了InterpreterContext::replece $this->value=null; } }}//操作符表达式 抽象基类abstract class OperatorExpression extends Expression{ //左右操作数 protected $l_op; protected $r_op; function __construct(Expression $l_op,Expression $r_op){ $this->l_op=$l_op; $this->r_op=$r_op; } function interpret(InterpreterContext $context){ $this->l_op->interpret($context); $this->r_op->interpret($context); $result_l=$context->lookup($this->l_op); $result_r=$context->lookup($this->r_op); $this->doInterpret($context, $result_l, $result_r); } protected abstract function doInterpret(InterpreterContext $context,$result_l,$result_r);}//相等表达式class EqualsExpression extends OperatorExpression{ //计算后将结果保存进this里... protected function doInterpret(InterpreterContext $context,$result_l,$result_r){ $context->replace($this, $result_l==$result_r); }}//布尔或表达式class BooleanOrExpression extends OperatorExpression{ protected function doInterpret(InterpreterContext $context, $result_l, $result_r){ $context->replace($this, $result_l || $result_r); }}//布尔与表达式class BooleanAndExpression extends OperatorExpression{ protected function doInterpret(InterpreterContext $context, $result_l, $result_r){ $context->replace($this, $result_l && $result_r); }}/*$context=new InterpreterContext();$literal=new LiteralExpression("Bob");$literal->interpret($context);print $context->lookup($literal);//Bob$context=new InterpreterContext();$myvar=new VariableExpression("V","one");$myvar->interpret($context);print $context->lookup($myvar);//one$myothervar=new VariableExpression("V");$myvar->interpret($context);print $context->lookup($myvar);//one*///利用上面的代码来检测迷你型语言//$input equals "4" or $input equals "four"$context=new InterpreterContext();//一个没有赋值的变量$input=new VariableExpression('input');//定义一个复杂的布尔型变量,初始化的参数被保存在l_op,r_op里面//注意,此时他们还没有进行相关运算,必须等到调用布尔型变量的interpret()//之后,布尔型变量里面的参数才会各自调用自身的interpret,形成一个调用栈...$statement=new BooleanOrExpression( new EqualsExpression($input, new LiteralExpression('four')), new EqualsExpression($input, new LiteralExpression('4')));$statement->interpret($context);print $context->lookup($statement);foreach (array('four','4','52') as $val){ $input->setValue($val); print "$val:\n"; $statement->interpret($context); if($context->lookup($statement)){ print "top marks\n"; }else{ print "dunce hat on\n\n"; }}/*four:top marks4:top marks52:dunce hat on*/ 2.策略模式 将类中许多不同操作而且是来自同一个接口的算法,独立起来封装在一个新类中,主类在由分类组合或者聚合而成//Question类将由Marker聚合而成abstract class Question{ protected $prompt; protected $marker; function __construct($prompt,Marker $marker){ $this->marker=$marker; $this->prompt=$prompt; } //利用委托实现 function mark($response){ return $this->marker->mark($response); }}class TextQuestion extends Question{ //处理文本问题特有的操作}class AVQuestion extends Question{ //处理语音问题特有操作}//策略对象//将算法部分独立出来封装在Marker类中....abstract class Marker{ protected $test; function __construct($test){ $this->test=$test; } abstract function mark($response);}//MarkLogic语言class MarkLogicMarker extends Marker{ protected $engine; function __construct($test){ parent::__construct($test); } function mark($response){ //模拟返回true return true; }}//直接匹配class MatchMarker extends Marker{ function mark($response){ return ($this->test==$response); }}//正则表达式class RegexpMarker extends Marker{ function mark($response){ return (preg_match($this->test, $response)); }}//客户端示例代码$markers=array(new RegexpMarker("/f.ve/"), new MatchMarker("fivev"), new MarkLogicMarker('$input equals "five"'));foreach($markers as $marker){ print get_class($marker)."\n"; //新建一个问题,将marker实例传进去 $question=new TextQuestion("How many beans make five", $marker); foreach (array("five","four") as $response){ print "\t response:$response: "; if($question->mark($response)){ print "well done\n"; }else{ print "never mind\n"; } }}/*RegexpMarker response:five: well done response:four: never mindMatchMarker response:five: never mind response:four: never mindMarkLogicMarker response:five: well done response:four: well done*/3 观察者模式 观察者模式的和兴是把客户元素(观察者)从一个中心类中分离开来.当主体中有事件发生时,观察者必须被通知到!同时观察者和主体类不是通过硬编码实现,而是通过接口组合聚合实现*问题// Login类(主体类)class Login { const LOGIN_USER_UNKNOWN = 1; const LOGIN_WRONG_PASS = 2; const LOGIN_ACCESS = 3; private $status = array (); // 登录操 function handleLogin($user, $pass, $ip) { $ret=false; switch (rand ( 1, 3 )) { case 1 : $this->setStatus ( self::LOGIN_ACCESS, $user, $ip ); $ret=ture; break; case 2 : $this->setStatus ( self::LOGIN_WRONG_PASS, $user, $ip ); $ret=false; break; case 3 : $this->setStatus ( self::LOGIN_USER_UNKNOWN, $user, $ip ); $ret=false; break; default: $ret=false; } //如果需要记录IP时 Logger::logIP($user, $ip, $this->getStatus()); //如果需要把登录失败的人的IP发送到管理员邮箱时... if(!$ret){ Notifier::mailWarning($user, $ip, $this->getStatus()); } //还需要其他功能时,比如特殊IP需要设置cookie等... //需要在这里面一直添加... return $ret; } function setStatus($status, $user, $ip) { $this->status = array ($status,$user,$ip); } function getStatus(){ return $this->status; }}class Logger{ static function logIP($user,$ip,$status){}}class Notifier{ static function mailWarning($user,$ip,$status){}}*利用观察者模式,使代码改动少些....// 主体类的抽象接口interface Observable{ //附加 function attach(Observer $observer); //删除 function detach(Observer $observer); //通知 function notify();}// Login类(主体类)class Login implements Observable{ const LOGIN_USER_UNKNOWN = 1; const LOGIN_WRONG_PASS = 2; const LOGIN_ACCESS = 3; private $observers; private $status = array (); // 登录操作 function handleLogin($user, $pass, $ip) { $ret=false; switch (rand ( 1, 3 )) { case 1 : $this->setStatus ( self::LOGIN_ACCESS, $user, $ip ); $ret=ture; break; case 2 : $this->setStatus ( self::LOGIN_WRONG_PASS, $user, $ip ); $ret=false; break; case 3 : $this->setStatus ( self::LOGIN_USER_UNKNOWN, $user, $ip ); $ret=false; break; default: $ret=false; } //使用观察者模式之后,如果需要增加新功能,只需要在本类中添加观察者实例即可... $this->notify(); return $ret; } function setStatus($status, $user, $ip) { $this->status = array ($status,$user,$ip); } function getStatus(){ return $this->status; } function attach(Observer $observer){ $this->observers[]=$observer; } function detach(Observer $observer){ $newObserver=array(); foreach ($this->observers as $obs){ if($obs!==$observer){ $newObserver[]=$obs; } } $this->observers=$newObserver; } //通知所有观察者 function notify(){ foreach ($this->observers as $bos){ $bos->update($this); } }}//观察者接口interface Observer{ function update(Observable $observable);}class SecurityMonitor implements Observer{ function update(Observable $observable){ //getStatus()不是Observable接口规定的方法 $status=$observable->getStatus(); //对status的判断也涉及到耦合问题 if($status[0]==Login::LOGIN_WRONG_PASS){ //发送邮件给管理员 print __CLASS__.":\t sending mail to sysadmin\n"; } }}$login=new Login();$login->attach(new SecurityMonitor());$login->handleLogin("coco", "123456", "127.0.0.1");//有可能输出发送消息到管理员 *改进后的观察者模式//可观察元素:主体类的基接口interface Observable{ //附加 function attach(Observer $observer); //删除 function detach(Observer $observer); //通知 function notify();}// Login类(主体类)class Login implements Observable{ const LOGIN_USER_UNKNOWN = 1; const LOGIN_WRONG_PASS = 2; const LOGIN_ACCESS = 3; private $observers; private $status = array (); // 登录操作 function handleLogin($user, $pass, $ip) { $ret=false; switch (rand ( 1, 3 )) { case 1 : $this->setStatus ( self::LOGIN_ACCESS, $user, $ip ); $ret=ture; break; case 2 : $this->setStatus ( self::LOGIN_WRONG_PASS, $user, $ip ); $ret=false; break; case 3 : $this->setStatus ( self::LOGIN_USER_UNKNOWN, $user, $ip ); $ret=false; break; default: $ret=false; } //使用观察者模式之后,如果需要增加新功能,只需要在本类中添加观察者实例即可... $this->notify(); return $ret; } function setStatus($status, $user, $ip) { $this->status = array ($status,$user,$ip); } function getStatus(){ return $this->status; } function attach(Observer $observer){ $this->observers[]=$observer; } function detach(Observer $observer){ $newObserver=array(); foreach ($this->observers as $obs){ if($obs!==$observer){ $newObserver[]=$obs; } } $this->observers=$newObserver; } //通知所有观察者 function notify(){ foreach ($this->observers as $bos){ $bos->update($this); } }}//观察者接口interface Observer{ function update(Observable $observable);}//Login:观察者超类(用于解决直接在Observer中调用具体的Observable子类造成的风险)abstract class LoginObserver implements Observer{ private $login; function __construct(Login $login){ $this->login=$login; $this->login->attach($this); } //该方法在Observable的子类某些方法被调用时触发 function update(Observable $observable){ //触发该方法时,传入的参数必须是Login才有效... if($this->login===$observable){ $this->doUpdate($observable); } } abstract function doUpdate(Login $login); }//改进后的观察者能保证调用的Observable实例方法一定存在class SecurityMonitor extends LoginObserver{ function doUpdate(Login $login){ $status=$login->getStatus(); //对status的判断也涉及到耦合问题 if($status[0]==Login::LOGIN_WRONG_PASS){ //发送邮件给管理员 print __CLASS__.":\t sending mail to sysadmin\n"; } }}//日常记录class GeneralLogger extends LoginObserver{ function doUpdate(Login $login){ $status=$login->getStatus(); //添加记录到log中 //... print __CLASS__."\t add login data to log\n"; }}//合作伙伴工具类class PartnershipTool extends LoginObserver{ function doUpdate(Login $login){ $status=$login->getStatus(); //检查IP,如果匹配,则设置cookie... //... print __CLASS__."\t set cookie if IP matches a list\n"; }}//客户端代码有一点点改变...$login=new Login();new SecurityMonitor($login);new GeneralLogger($login);new PartnershipTool($login);$login->handleLogin("coco", "123456", "127.0.0.1");/* * 有可能输出 *SecurityMonitor: sending mail to sysadmin *GeneralLogger add login data to log *PartnershipTool set cookie if IP matches a list **/4. 访问者模式 当使用对象集合时,我们可能需要对结构上每一个单独的组件应用各种操作.这样的操作可以内建于组件本身,毕竟组件内部调用其他组件是最方便的. 但是这种方法也存在问题,因为我们并不知道所有可能需要的执行的操作.如果每增加一个操作,就在类中增加一个对于新操作的支持,类就会变得越来越臃肿.访问者模式可以解决这个问题.//本例是基于"文明"游戏的代码建立而成...//*战斗单元类abstract class Unit{ //深度 protected $depth=0; //攻击强度 abstract function bombardStrength(); function getComposite(){ return null; } //为访问者模式打造的方法 function accept(ArmyVisitor $visitor){ //构建一个根据自己规则定义的方法名,然后交给visitor自身调用 $method="visit".get_class($this); $visitor->$method($this); } //用于计算Unit在对象树中的深度 protected function setDepth($depth){ $this->depth==$depth; } function getDepth(){ return $this->depth; }}//复合抽象类abstract class CompositeUnit extends Unit{ protected $units=array(); //为访问者模式打造的方法 function accept(ArmyVisitor $visitor){ //构建一个根据自己规则定义的方法名,然后交给visitor自身调用 //先调用父类accept(),再遍历调用子元素accept() parent::accept($visitor); foreach ($this->units as $thisunit){ $thisunit->accept($visitor); } } //可以不用写bombardStrength() function getComposite(){ return $this; } //添加单元 //同时标记节点在对象树中的深度 function addUnit(Unit $unit){ if(!empty($unit)){ if(in_array($unit, $this->units,true)){ return; } //可以用下面代码替换in_array()函数// foreach ($this->units as $thisunit){// if($thisunit===$unit){// return;// }// } //计算好深度先... $unit->setDepth($this->depth+1); array_push($this->units, $unit); } } function removeUnit(Unit $unit){ $this->units=array_udiff($this->units, array($unit), function ($a,$b){return ($a===$b?0:1);}); } }//射手class Archer extends Unit{ function bombardStrength(){ return 4; }}//激光塔class LaserCannonUnit extends Unit{ function bombardStrength(){ return 44; }}//军队:由战斗单元组成class Army extends CompositeUnit{ //计算总强度 function bombardStrength(){ $ret=0; foreach ($this->units as $unit){ $ret+=$unit->bombardStrength(); } return $ret; } //移动能力,防御能力...省略}//运兵船:一个类似军队的单元,它具备10个战斗单元,有攻击力class TroopCarrier extends CompositeUnit{ //具备和军队差不多的方法和属性 function bombardStrength(){ //Do something... }}//军队访问者基类abstract class ArmyVisitor{ //相关方法待会写... //Army可能有多少种Unit,这里就有多少个visit方法... //方法命名规则为visit+类名 //默认的visit abstract function visit(Unit $unit); function visitArcher(Archer $node){ $this->visit($node); } function visitLaserCannonUnit(LaserCannonUnit $node){ $this->visit($node); } function visitArmy(Army $node){ $this->visit($node); } function visitTroopCarrier(TroopCarrier $node){ $this->visit($node); }}//具体的Army访问者类,用于转存文本class TextDumpArmyVisitor extends ArmyVisitor{ private $text=""; function visit(Unit $node){ $ret=""; $pad=4*$node->getDepth(); $ret.=sprintf("%{$pad}s",""); $ret.=get_class($node).":"; $ret.="bombard: ".$node->bombardStrength()."\n"; $this->text.=$ret; } function getText(){ return $this->text; }}//客户端实例代码$army=new Army();$army->addUnit(new Archer());$army->addUnit(new LaserCannonUnit());$textdump=new TextDumpArmyVisitor();$army->accept($textdump);print $textdump->getText();/* * Army:bombard: 48 * Archer:bombard: 4 * LaserCannonUnit:bombard: 44 */5. 命令模式//命令模式//命令模式最初来源于图形化用户界面设计,但现在广泛应用于企业应用设计,特别促进了控制器(请求和分法处理)//和领域模型(应用逻辑)的分离.说得更简单一点,命令模式有助于系统更好地进行组织,并易于扩展//Command可以设计成接口,因为它很简单...//Commands/Command.phpabstract class Command{ abstract function execute(CommandContext $context);} require_once("Command.php");class Registry{ //一个空类... static function getAccessManager(){ return new AccessManager(); }}class AccessManager{ function login(){ return new stdClass(); } function getError(){}}class LoginCommand extends Command{ function execute(CommandContext $context){ $manager=Registry::getAccessManager(); $user=$context->get('username'); $user=$context->get('pass'); //虚构出来的空类空方法 $user_obj=$manager->login(); if(is_null($user_obj)){ $context->setError($manager->getError()); return false; } $context->addParam("user", $user); return true; }} //CommandContext类用来做任务扩增用,在这儿主要功能是传递数据给Command类class CommandContext{ private $params=array(); private $error=""; function __construct(){ $this->params=$_REQUEST; } function addParam($key,$val){ $this->params[$key]=$val; } function get($key){ return $this->params[$key]; } function setError($error){ $this->error=$error; } function getError(){ return $this->error; }}//客户端代码(用于创建命令)已经调用者代码class CommandNotFoundException extends Exception{ }//创建命令的工厂class CommandFactory{ private static $dir="Commands"; //根据参数action,以及类文件存放目录$dir动态创建相应的$action+Command类 static function getCommand($action='default'){ //匹配是否出现非法字符(非字母数字下划线) if(preg_match('/\W/', $action)){ throw new Exception("Illegal characters in action"); } $class=ucfirst(strtolower($action)."Command"); $file=self::$dir.DIRECTORY_SEPARATOR."{$class}.php"; if(!file_exists($file)){ throw new CommandNotFoundException("File could not be find !"); } require_once("$file"); if(!class_exists($class)){ throw new CommandNotFoundException("Class could not be find !"); } return new $class(); }}//调用者,里面包含一个CommandContext对象实例,用于存放web请求的数据class Controller{ private $context; function __construct(){ $this->context=new CommandContext(); } function getContext(){ return $this->context; } function process(){ $cmd=CommandFactory::getCommand($this->getContext()->get('action')); if(!$cmd->execute($this->context)){ //处理失败 print "Faile in process!"; }else{ //处理成功,可以显示相应的视图层 print "Success in process!"; } }}$controller=new Controller();$context=$controller->getContext();$context->addParam('action', 'Login');$context->addParam('user', 'cocos');$context->addParam('pass', 'tiddles');//controller执行process方法,需要不理解command的意义.$controller->process();//Success in process
