__PHP_Incomplete_Class 错误处理

//该错误通常是两套php代码公用了redis,mysql等数据
class A{  
   public $name = 'admin_a';    
} 
class B{ 
   public $name = 'admin_b'; 
} 

$objA = new A(); 
$objB = new B(); 

$serializedObjA = serialize($objA); 
$serializedObjB = serialize($objB); 

//如果classA 不存在与代码，那么就会返回__PHP_Incomplete_Class
$dataA = unserialize($serializedObjA);