private static function getCacheFile()
 {
     self::$accessRule = F('access/rule');
     if (!self::$accessRule) {
         //生成公共模块缓存
         $rsPub = M('admin_node')->field('n_group,n_action')->where(array('is_public_action' => 1))->findAll();
         if ($rsPub) {
             foreach ($rsPub as $val) {
                 self::$accessRule['public'][$val['n_group']][$val['n_action']] = 1;
             }
         } else {
             self::$accessRule['public'] = array();
         }
         //生成用户组缓存
         $rsUser = M('admin_access')->field('group_id,n_group,n_action,n_model')->findAll();
         if ($rsUser) {
             foreach ($rsUser as $val) {
                 self::$accessRule['user'][$val['group_id']][$val['n_group']][$val['n_action']][$val['n_model']] = 1;
             }
         } else {
             self::$accessRule['user'] = array();
         }
         F('access/rule', self::$accessRule);
     }
     return true;
 }