時間長度格式化的方法，把時間長度轉換為xx:xx:xx的格式。記錄下來，以備不時之需。

public String secToTime(int time) {
    String timeStr = null;
    int hour = 0;
    int minute = 0;
    int second = 0;
    if (time <= 0)
        return "00:00";
    else {
        minute = time / 60;
        if (minute < 60) {
            second = time % 60;
            timeStr = unitFormat(minute) + ":" + unitFormat(second);
        } else {
            hour = minute / 60;
            if (hour > 99)
                return "99:59:59";
            minute = minute % 60;
            second = time - hour * 3600 - minute * 60;
            timeStr = unitFormat(hour) + ":" + unitFormat(minute) + ":" + unitFormat(second);
        }
    }
    return timeStr;
}

public String unitFormat(int i) {
    String retStr = null;
    if (i >= 0 && i < 10)
        retStr = "0" + Integer.toString(i);
    else
        retStr = "" + i;
    return retStr;
}