PHP地址反查返回经纬度 百度API

/**
     * 百度地图   根据地址反查经纬度
     */
    
    public function search_xy(){
      $address = str_replace(' ','',$address);
      $rows = file_get_contents("http://api.map.baidu.com/geocoder/v2/?ak=xxxxxxxxxxxxxx&callback=renderOption&output=json&address=首都图书馆&city=北京市朝阳区);
      $start = $this->getPos($rows,"{",2);
      $end = $this->getPos($rows,"}",2);  
      $json = mb_substr($rows, $start[2],intval($end[3])-intval($start[2])+1);
      $xy = json_decode($json,true); 
      return $xy;
    }