PHPのリフレクションメカニズムの原理は何ですか?反射機構の機能を詳しく解説

<?php
class person{
public $name;
public $gender;
public function say(){
  echo $this->name," \tis ",$this->gender,"\r\n";
}
public function set($name, $value) {
  echo "Setting $name to $value \r\n";
  $this->$name= $value;
}
public function get($name) {
  if(!isset($this->$name)){
    echo &#39;未设置&#39;;
     　　
     $this->$name="正在为你设置默认值";
  }
  return $this->$name;
  }
}
$student=new person();
$student->name=&#39;Tom&#39;;
$student->gender=&#39;male&#39;;
$student->age=24;

// 获取对象属性列表
$reflect = new ReflectionObject($student);
$props　= $reflect->getProperties();
foreach ($props as $prop) {
  print $prop->getName() ."\n";
}
// 获取对象方法列表
$m=$reflect->getMethods();
foreach ($m as $prop) {
  print $prop->getName() ."\n";
}

// 返回对象属性的关联数组
var_dump(get_object_vars($student));
// 类属性
var_dump(get_class_vars(get_class($student)));
// 返回由类的方法名组成的数组
var_dump(get_class_methods(get_class($student)));

// 获取对象属性列表所属的类
echo get_class($student);

// 反射获取类的原型
$obj = new ReflectionClass('person');
$className = $obj->getName();
$Methods = $Properties = array();
foreach($obj->getProperties() as $v)
{
　　　　$Properties［$v->getName()］ = $v;
}
foreach($obj->getMethods() as $v)
 　　
 {
　　　　$Methods［$v->getName()］ = $v;
}
echo "class {$className}\n{\n";
is_array($Properties)&&ksort($Properties);
foreach($Properties as $k => $v)
{
　　　　echo "\t";
　　　　echo $v->isPublic() ? ' public' : '',$v->isPrivate() ? ' private' : '',
　　　　$v->isProtected() ? ' protected' : '',
　　　　$v->isStatic() ? ' static' : '';
　　　　echo "\t{$k}\n";
}
echo "\n";
if(is_array($Methods)) ksort($Methods);
foreach($Methods as $k => $v)
{
　　　　echo "\tfunction {$k}(){}\n";
}
echo "}\n";

class person
{
  public　gender
  public　name
  function get(){}
  function set(){}
  function say(){}
}

<?php
class mysql {
  function connect($db) {
    echo "连接到数据库${db［0］}\r\n";
  }
}
class sqlproxy {
  private $target;  
  function construct($tar) { 
    $this->target［］ = new $tar();
  }
  function call($name, $args) {
    foreach ($this->target as $obj) {
      $r = new ReflectionClass($obj);
      if ($method = $r->getMethod($name)) {
        if ($method->isPublic() && !$method->isAbstract()) {
          echo "方法前拦截记录LOG\r\n";
          $method->invoke($obj, $args);
          echo "方法后拦截\r\n";
        }
      }
    }
  }
}
$obj = new sqlproxy(&#39;mysql&#39;);
$obj->connect(&#39;member&#39;);