func GetMgoURL(ip, user, password string, port int) string {
    urlString := ""
    if user == "" && password == "" {
        urlString = fmt.Sprintf("mongodb://%s:%d/admin", ip, port)
    }else {
        urlString = fmt.Sprintf("mongodb://%s:%s@%s:%d/admin", url.QueryEscape(user), url.QueryEscape(password), ip, port)
    }

    return urlString
}


url := service.GetMgoURL(reqPara.Ip, reqPara.User, reqPara.Password, reqPara.Port)
    session, err := mgo.Dial(url)