public function getAnchorByPopularity($page, $pagesize){

        //验证参数的正确性

        if(!is_numeric($page) || !is_numeric($pagesize)){

            throw new Exception(__METHOD__ . "error param");

        }

        $page = ($page > 0) ? $page - 1 : 0;

        $pagesize = ($pagesize > 0) ? $pagesize : 20;

        $param = func_get_args();

        $redisKey = "autoapp_".__METHOD__ . implode("_", $param);

        $redisVal = $this->redis->get($redisKey);

        if($redisVal === false){

            if ($pagesize > 0) {

                $start = $page * $pagesize;

                $order = "FPopularity desc";

                $limit = "{$start}, {$pagesize}";

               // $limit = "{0},{1}";

            } else {

                $limit = "";

            }

            //从MySQL数据库读取数据

            //如果读取数据不为空，把数据存入redis

            if(!empty($list)){

                $this->redis->setex($redisKey, $this->cacheTime, $list);

            }

        }

        else{

            $list = unserialize($redisVal);

        }

        return $list;

    }