zoukankan      html  css  js  c++  java
  • PHP面向对象深入研究之【了解类】与【反射API】

    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 object
    ";
    }
    
    ?>
    
    <?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 object
    ";
    }
    ?>
    

    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 "title
    "; }
        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 ShopProduct
    ";
    }
    
    if ( is_subclass_of( $product, 'incidental' ) ) {
        print "CdProduct is a subclass of incidental
    ";
    }
    
    if ( in_array( 'incidental', class_implements( $product )) ) {
        print "CdProduct is an interface of incidental
    ";
    }
    
    ?>
    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 "thing
    ";
        }
        function andAnotherthing() {
            print "another thing
    ";
        }
    }
    
    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 "thing
    ";
        }
        function andAnotherthing( $a, $b ) {
            print "another thing ($a, $b)
    ";
        }
    }
    
    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()."
    ";
    $product2 = new BookProduct("book1", "harry", "harrelson", 4, 30 );
    print $product2->getSummaryLine()."
    ";
    */
    ?>
    
    <?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 defined
    ";
      }
      if ( $class->isInternal() ) {
        $details .= "$name is built-in
    ";
      }
      if ( $class->isInterface() ) {
        $details .= "$name is interface
    ";
      }
      if ( $class->isAbstract() ) {
        $details .= "$name is an abstract class
    ";
      }
      if ( $class->isFinal() ) {
        $details .= "$name is a final class
    ";
      }
      if ( $class->isInstantiable() ) {
        $details .= "$name can be instantiated
    ";
      } else {
        $details .= "$name can not be instantiated
    ";
      }
      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 "
    ----
    ";
    }
    
    function methodData( ReflectionMethod $method ) {
      $details = "";
      $name = $method->getName();
      if ( $method->isUserDefined() ) {
        $details .= "$name is user defined
    ";
      }
      if ( $method->isInternal() ) {
        $details .= "$name is built-in
    ";
      }
      if ( $method->isAbstract() ) {
        $details .= "$name is abstract
    ";
      }
      if ( $method->isPublic() ) {
        $details .= "$name is public
    ";
      }
      if ( $method->isProtected() ) {
        $details .= "$name is protected
    ";
      }
      if ( $method->isPrivate() ) {
        $details .= "$name is private
    ";
      }
      if ( $method->isStatic() ) {
        $details .= "$name is static
    ";
      }
      if ( $method->isFinal() ) {
        $details .= "$name is final
    ";
      }
      if ( $method->isConstructor() ) {
        $details .= "$name is the constructor
    ";
      }
      if ( $method->returnsReference() ) {
        $details .= "$name returns a reference (as opposed to a value)
    ";
      }
      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 )."
    ";
    }
    
    function argData( ReflectionParameter $arg ) {
      $details = "";
      $declaringclass = $arg->getDeclaringClass();
      $name  = $arg->getName();
      $class = $arg->getClass();
      $position = $arg->getPosition();
      $details .= "$$name has position $position
    ";
      if ( ! empty( $class )  ) {
        $classname = $class->getName();
        $details .= "$$name must be a $classname object
    ";
      }
      
      if ( $arg->isPassedByReference() ) {
        $details .= "$$name is passed by reference
    ";
      }
    
      if ( $arg->isDefaultValueAvailable()  ) {
        $def = $arg->getDefaultValue();
        $details .= "$$name has default: $def
    ";
      }
    
      if ( $arg->allowsNull()  ) { 
        $details .= "$$name can be null
    ";
      }
    
      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
    
  • 相关阅读:
    Pythonday01
    PYTHON_DAY2
    PYTHON_DAY3
    数据字典生成SQL语句
    Spring cloud Netflix >readMe
    SecureCRT的安装与激活
    MyBatis映射文件UserMapper.xml(mysql环境)
    数据库模糊查询4种用法
    MyBatis配置文件myBatisconfig.xml
    计算机基础:2进制和2进制算法。
  • 原文地址:https://www.cnblogs.com/jiqing9006/p/5171327.html
Copyright © 2011-2022 走看看