將日期格式轉換為毫秒

要以 dd / MM / yyyy 格式將日期轉換為毫秒，可以使用資料作為字串呼叫此函式

public long getMilliFromDate(String dateFormat) {
    Date date = new Date();
    SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
    try {
        date = formatter.parse(dateFormat);
    } catch (ParseException e) {
        e.printStackTrace();
    }
    System.out.println("Today is " + date);
    return date.getTime();
}

此方法將毫秒轉換為時間戳格式日期：

public String getTimeStamp(long timeinMillies) {
    String date = null;
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); // modify format
    date = formatter.format(new Date(timeinMillies));
    System.out.println("Today is " + date);

    return date;
}

此方法將特定的日，月和年轉換為毫秒。使用 Timpicker 或 Datepicker 時會非常有幫助

public static long getTimeInMillis(int day, int month, int year) {
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month, day);
    return calendar.getTimeInMillis();
}

它將從日期返回毫秒

public static String getNormalDate(long timeInMillies) {
    String date = null;
    SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
    date = formatter.format(timeInMillies);
    System.out.println("Today is " + date);
    return date;
}

它將返回當前日期

public static String getCurrentDate() {
    Calendar c = Calendar.getInstance();
    System.out.println("Current time => " + c.getTime());
    SimpleDateFormat df = new SimpleDateFormat("dd/MM/yyyy");
    String formattedDate = df.format(c.getTime());
    return formattedDate;
}

注意： Java 提供日期格式支援日期模式的數量