/**
 * 对象转关联数组
 * @author 
 * @param object $obj
 * @return array
 */
 function object_to_array($obj){
    $_arr = is_object($obj) ? get_object_vars($obj) : $obj;
    foreach ($_arr as $key => $val){
       $val = (is_array($val) || is_object($val)) ? $this->object_to_array($val) : $val;
       $arr[$key] = $val;
    }
    return $arr;
}