php中怎么在外部修改类的私有或受保护属性值

在做单元测试框架时，发现了个比较郁闷的问题：测试人员需要在类外修改类的private或protected成员变量的值，而这些变量没有抽象成public的属性，同时为了代码量的问题，也不可能修改要测试的类。怎么在类外修改类的私有变量呢？请看下面的关键代码：

类文件sellAction.php， 内容如下：

class SellAction{

protected $cUid;

private $id;

public $pId;

public function output(){

echo "output protected cUid :".$this->cUid;

echo "
";

echo "output private id :".$this->id;

echo "
";

echo "output public pId:".$this->pId;

echo "
";

}

}

测试文件test.php，内容如下：

require "sellAction.php";

function initReferenceAttr(& $reference, $arr)

{

if(!is_object($reference))

{

throw new Exception('reference must be object');

}

if(!is_array($arr))

{

throw new Exception('arr must be array');

}

$cls = get_class($reference);

$reflectCls = new ReflectionClass ($cls);

foreach($arr as $key => $val)

{

$pro = $reflectCls->getProperty($key);

if($pro && ($pro->isPrivate() || $pro->isProtected())){

$pro->setAccessible(true);

$pro->setValue($reference, $val);

}else{

$reference->$key = $val;

}

}

return true;

}

$act = new SellAction();

echo "not set private protect public var";

echo "
";

var_dump($act);

$act->output();

$attr = array('cUid'=>'234556', 'pId'=>'987676757', 'id'=> '782100');

initReferenceAttr($act, $attr);

echo "
";

print_r($attr);

echo "
";

echo "
";

echo "set private protect public var ";

echo "
";

var_dump($act);

echo "
";

$act->output();

在浏览器中，直接浏览test.php，内容大致如下：

not set private protect public var

object(SellAction)#1 (3) { ["cUid":protected]=> NULL ["id":"SellAction":private]=> NULL ["pId"]=> NULL } output protected cUid :

output private id :

output public pId:

Array ( [cUid] => 234556 [pId] => 987676757 [id] => 782100 )

set private protect public var

object(SellAction)#1 (3) { ["cUid":protected]=> string(6) "234556" ["id":"SellAction":private]=> string(6) "782100" ["pId"]=> string(9) "987676757" }

output protected cUid :234556

output private id :782100

output public pId:987676757

上面的demo主要是通过反射实现该功能。反射功能需要php版本>=5.3，反射的相关信息请参阅：http://php.net/manual/en/book.reflection.php