本文实例讲述了PHP面向对象程序设计之类与反射API。分享给大家供大家参考,具体如下:
了解类
class_exists验证类是否存在
<?php // TaskRunner.php $classname = "Task"; $path = "tasks/{$classname}.php"; if ( ! file_exists( $path ) ) { throw new Exception( "No such file as {$path}" ); //抛出异常,类文件不存在 } require_once( $path ); $qclassname = "tasks\$classname"; if ( ! class_exists( $qclassname ) ) { throw new Exception( "No such class as $qclassname" ); //抛出异常,类不存在Fatal error: Uncaught exception 'Exception' with message 'No such class as tasksTask' Stack trace: #0 {main} } $myObj = new $qclassname(); $myObj->doSpeak(); ?>
get_class 检查对象的类 instanceof 验证对象是否属于某个类
<?php class CdProduct {} function getProduct() { return new CdProduct( "Exile on Coldharbour Lane", "The", "Alabama 3", 10.99, 60.33 ); // 返回一个类对象 } $product = getProduct(); if ( get_class( $product ) == 'CdProduct' ) { print "$product is a CdProduct objectn"; } ?> <?php class CdProduct {} function getProduct() { return new CdProduct( "Exile on Coldharbour Lane", "The", "Alabama 3", 10.99, 60.33 ); } $product = getProduct(); if ( $product instanceof CdProduct ) { print "$product is a CdProduct objectn"; } ?>
get_class_methods 得到类中所有的方法列表,只获取public的方法,protected,private的方法获取不到。默认的就是public。
<?php class CdProduct { function __construct() { } function getPlayLength() { } function getSummaryLine() { } function getProducerFirstName() { } function getProducerMainName() { } function setDiscount() { } function getDiscount() { } function getTitle() { } function getPrice() { } function getProducer() { } } print_r( get_class_methods( 'CdProduct' ) ); ?>
output:
Array ( [0] => __construct [1] => getPlayLength [2] => getSummaryLine [3] => getProducerFirstName [4] => getProducerMainName [5] => setDiscount [6] => getDiscount [7] => getTitle [8] => getPrice [9] => getProducer )
更多验证
<?php class ShopProduct {} interface incidental {}; class CdProduct extends ShopProduct implements incidental { public $coverUrl; function __construct() { } function getPlayLength() { } function getSummaryLine() { } function getProducerFirstName() { } function getProducerMainName() { } function setDiscount() { } function getDiscount() { } function getTitle() { return "titlen"; } function getPrice() { } function getProducer() { } } function getProduct() { return new CdProduct(); } $product = getProduct(); // acquire an object $method = "getTitle"; // define a method name print $product->$method(); // invoke the method if ( in_array( $method, get_class_methods( $product ) ) ) { print $product->$method(); // invoke the method } if ( is_callable( array( $product, $method) ) ) { print $product->$method(); // invoke the method } if ( method_exists( $product, $method ) ) { print $product->$method(); // invoke the method } print_r( get_class_vars( 'CdProduct' ) ); if ( is_subclass_of( $product, 'ShopProduct' ) ) { print "CdProduct is a subclass of ShopProductn"; } if ( is_subclass_of( $product, 'incidental' ) ) { print "CdProduct is a subclass of incidentaln"; } if ( in_array( 'incidental', class_implements( $product )) ) { print "CdProduct is an interface of incidentaln"; } ?>
output:
title title title title Array ( [coverUrl] => ) CdProduct is a subclass of ShopProduct CdProduct is a subclass of incidental CdProduct is an interface of incidental
__call方法
<?php class OtherShop { function thing() { print "thingn"; } function andAnotherthing() { print "another thingn"; } } class Delegator { private $thirdpartyShop; function __construct() { $this->thirdpartyShop = new OtherShop(); } function __call( $method, $args ) { // 当调用未命名方法时执行call方法 if ( method_exists( $this->thirdpartyShop, $method ) ) { return $this->thirdpartyShop->$method( ); } } } $d = new Delegator(); $d->thing(); ?>
output:
thing
传参使用
<?php class OtherShop { function thing() { print "thingn"; } function andAnotherthing( $a, $b ) { print "another thing ($a, $b)n"; } } class Delegator { private $thirdpartyShop; function __construct() { $this->thirdpartyShop = new OtherShop(); } function __call( $method, $args ) { if ( method_exists( $this->thirdpartyShop, $method ) ) { return call_user_func_array( array( $this->thirdpartyShop, $method ), $args ); } } } $d = new Delegator(); $d->andAnotherThing( "hi", "hello" ); ?>
output:
another thing (hi, hello)
反射API
fullshop.php
<?php class ShopProduct { private $title; private $producerMainName; private $producerFirstName; protected $price; private $discount = 0; public function __construct( $title, $firstName, $mainName, $price ) { $this->title = $title; $this->producerFirstName = $firstName; $this->producerMainName = $mainName; $this->price = $price; } public function getProducerFirstName() { return $this->producerFirstName; } public function getProducerMainName() { return $this->producerMainName; } public function setDiscount( $num ) { $this->discount=$num; } public function getDiscount() { return $this->discount; } public function getTitle() { return $this->title; } public function getPrice() { return ($this->price - $this->discount); } public function getProducer() { return "{$this->producerFirstName}". " {$this->producerMainName}"; } public function getSummaryLine() { $base = "{$this->title} ( {$this->producerMainName}, "; $base .= "{$this->producerFirstName} )"; return $base; } } class CdProduct extends ShopProduct { private $playLength = 0; public function __construct( $title, $firstName, $mainName, $price, $playLength=78 ) { parent::__construct( $title, $firstName, $mainName, $price ); $this->playLength = $playLength; } public function getPlayLength() { return $this->playLength; } public function getSummaryLine() { $base = parent::getSummaryLine(); $base .= ": playing time - {$this->playLength}"; return $base; } } class BookProduct extends ShopProduct { private $numPages = 0; public function __construct( $title, $firstName, $mainName, $price, $numPages ) { parent::__construct( $title, $firstName, $mainName, $price ); $this->numPages = $numPages; } public function getNumberOfPages() { return $this->numPages; } public function getSummaryLine() { $base = parent::getSummaryLine(); $base .= ": page count - {$this->numPages}"; return $base; } public function getPrice() { return $this->price; } } /* $product1 = new CdProduct("cd1", "bob", "bobbleson", 4, 50 ); print $product1->getSummaryLine()."n"; $product2 = new BookProduct("book1", "harry", "harrelson", 4, 30 ); print $product2->getSummaryLine()."n"; */ ?> <?php require_once "fullshop.php"; $prod_class = new ReflectionClass( 'CdProduct' ); Reflection::export( $prod_class ); ?>
output:
Class [ <user> class CdProduct extends ShopProduct ] { @@ D:xampphtdocspopp-code5fullshop.php 53-73 - Constants [0] { } - Static properties [0] { } - Static methods [0] { } - Properties [2] { Property [ <default> private $playLength ] Property [ <default> protected $price ] } - Methods [10] { Method [ <user, overwrites ShopProduct, ctor> public method __construct ] { @@ D:xampphtdocspopp-code5fullshop.php 56 - 61 - Parameters [5] { Parameter #0 [ <required> $title ] Parameter #1 [ <required> $firstName ] Parameter #2 [ <required> $mainName ] Parameter #3 [ <required> $price ] Parameter #4 [ <optional> $playLength = 78 ] } } Method [ <user> public method getPlayLength ] { @@ D:xampphtdocspopp-code5fullshop.php 63 - 65 } Method [ <user, overwrites ShopProduct, prototype ShopProduct> public method getSummaryLine ] { @@ D:xampphtdocspopp-code5fullshop.php 67 - 71 } Method [ <user, inherits ShopProduct> public method getProducerFirstName ] { @@ D:xampphtdocspopp-code5fullshop.php 17 - 19 } Method [ <user, inherits ShopProduct> public method getProducerMainName ] { @@ D:xampphtdocspopp-code5fullshop.php 21 - 23 } Method [ <user, inherits ShopProduct> public method setDiscount ] { @@ D:xampphtdocspopp-code5fullshop.php 25 - 27 - Parameters [1] { Parameter #0 [ <required> $num ] } } Method [ <user, inherits ShopProduct> public method getDiscount ] { @@ D:xampphtdocspopp-code5fullshop.php 29 - 31 } Method [ <user, inherits ShopProduct> public method getTitle ] { @@ D:xampphtdocspopp-code5fullshop.php 33 - 35 } Method [ <user, inherits ShopProduct> public method getPrice ] { @@ D:xampphtdocspopp-code5fullshop.php 37 - 39 } Method [ <user, inherits ShopProduct> public method getProducer ] { @@ D:xampphtdocspopp-code5fullshop.php 41 - 44 } } }
点评:把类看的透彻的一塌糊涂,比var_dump强多了。哪些属性,继承了什么类。类中的方法哪些是自己的,哪些是重写的,哪些是继承的,一目了然。
查看类数据
<?php require_once("fullshop.php"); function classData( ReflectionClass $class ) { $details = ""; $name = $class->getName(); if ( $class->isUserDefined() ) { $details .= "$name is user definedn"; } if ( $class->isInternal() ) { $details .= "$name is built-inn"; } if ( $class->isInterface() ) { $details .= "$name is interfacen"; } if ( $class->isAbstract() ) { $details .= "$name is an abstract classn"; } if ( $class->isFinal() ) { $details .= "$name is a final classn"; } if ( $class->isInstantiable() ) { $details .= "$name can be instantiatedn"; } else { $details .= "$name can not be instantiatedn"; } return $details; } $prod_class = new ReflectionClass( 'CdProduct' ); print classData( $prod_class ); ?>
output:
CdProduct is user defined
CdProduct can be instantiated
查看方法数据
<?php require_once "fullshop.php"; $prod_class = new ReflectionClass( 'CdProduct' ); $methods = $prod_class->getMethods(); foreach ( $methods as $method ) { print methodData( $method ); print "n----n"; } function methodData( ReflectionMethod $method ) { $details = ""; $name = $method->getName(); if ( $method->isUserDefined() ) { $details .= "$name is user definedn"; } if ( $method->isInternal() ) { $details .= "$name is built-inn"; } if ( $method->isAbstract() ) { $details .= "$name is abstractn"; } if ( $method->isPublic() ) { $details .= "$name is publicn"; } if ( $method->isProtected() ) { $details .= "$name is protectedn"; } if ( $method->isPrivate() ) { $details .= "$name is privaten"; } if ( $method->isStatic() ) { $details .= "$name is staticn"; } if ( $method->isFinal() ) { $details .= "$name is finaln"; } if ( $method->isConstructor() ) { $details .= "$name is the constructorn"; } if ( $method->returnsReference() ) { $details .= "$name returns a reference (as opposed to a value)n"; } return $details; } ?>
output:
__construct is user defined __construct is public __construct is the constructor ---- getPlayLength is user defined getPlayLength is public ---- getSummaryLine is user defined getSummaryLine is public ---- getProducerFirstName is user defined getProducerFirstName is public ---- getProducerMainName is user defined getProducerMainName is public ---- setDiscount is user defined setDiscount is public ---- getDiscount is user defined getDiscount is public ---- getTitle is user defined getTitle is public ---- getPrice is user defined getPrice is public ---- getProducer is user defined getProducer is public
获取构造函数参数情况
<?php require_once "fullshop.php"; $prod_class = new ReflectionClass( 'CdProduct' ); $method = $prod_class->getMethod( "__construct" ); $params = $method->getParameters(); foreach ( $params as $param ) { print argData( $param )."n"; } function argData( ReflectionParameter $arg ) { $details = ""; $declaringclass = $arg->getDeclaringClass(); $name = $arg->getName(); $class = $arg->getClass(); $position = $arg->getPosition(); $details .= "$$name has position $positionn"; if ( ! empty( $class ) ) { $classname = $class->getName(); $details .= "$$name must be a $classname objectn"; } if ( $arg->isPassedByReference() ) { $details .= "$$name is passed by referencen"; } if ( $arg->isDefaultValueAvailable() ) { $def = $arg->getDefaultValue(); $details .= "$$name has default: $defn"; } if ( $arg->allowsNull() ) { $details .= "$$name can be nulln"; } return $details; } ?>
output:
$title has position 0 $title can be null $firstName has position 1 $firstName can be null $mainName has position 2 $mainName can be null $price has position 3 $price can be null $playLength has position 4 $playLength has default: 78 $playLength can be null
希望本文所述对大家PHP程序设计有所帮助。