js时间毫秒转换为字符串时分秒

convertTimeFormat(timems) {
    let str = '';
    const time = parseInt(timems);
    const hour = Math.floor(time / 3600);
    const hourFormat = hour > 9 ? hour : ('0' + hour);
    const minute = Math.floor((time - hour * 3600) / 60);
    const minuteFormat = minute > 9 ? minute : ('0' + minute);
    const second = Math.floor((time - hour * 3600) - minute * 60);
    const secondFormat = second > 9 ? second : ('0' + second);
    str += hourFormat + ":" + minuteFormat + ":" + secondFormat;
    return str;
  }