常量日期和当前日期之间的差异(Joda)

你可以使用Days.daysBetween(jodaDate1,jodaDate2)

这里有一个例子:

        val dateTime: DateTime = DateTime.parse("14/09/2020",
            DateTimeFormat.forPattern("dd/MM/yyyy"))
        val currentDate = DateTime.now()
        //To calculate the days in between
        val dayCount = Days.daysBetween(dateTime,currentDate).days
        //Set Value to TextView 
        binding.daysCount.text = dayCount.toString()

public static int getDifferenceIndays(long timestamp1, long timestamp2) {
    final int SECONDS = 60;
    final int MINUTES = 60;
    final int HOURS = 24;
    final int MILLIES = 1000;
    long temp;
    if (timestamp1 < timestamp2) {
        temp = timestamp1;
        timestamp1 = timestamp2;
        timestamp2 = temp;
    }
    Calendar startDate = Calendar.getInstance(TimeZone.getDefault());
    Calendar endDate = Calendar.getInstance(TimeZone.getDefault());
    endDate.setTimeInMillis(timestamp1);
    startDate.setTimeInMillis(timestamp2);
    if ((timestamp1 - timestamp2) < 1 * HOURS * MINUTES * SECONDS * MILLIES) {
        int day1 = endDate.get(Calendar.DAY_OF_MONTH);
        int day2 = startDate.get(Calendar.DAY_OF_MONTH);
        if (day1 == day2) {
            return 0;
        } else {
            return 1;
        }
    }
    int diffDays = 0;
    startDate.add(Calendar.DAY_OF_MONTH, diffDays);
    while (startDate.before(endDate)) {
        startDate.add(Calendar.DAY_OF_MONTH, 1);
        diffDays++;
    }
    return diffDays;
}

java.time.Period

使用java.time.Period类计算天数。

由于Java 8计算差异时使用LocalDate、LocalDateTime来表示两个日期更为直观

    LocalDate now = LocalDate.now();
    LocalDate inputDate = LocalDate.of(2018, 11, 28);

    Period period = Period.between( inputDate, now);
    int diff = period.getDays();
    System.out.println("diff = " + diff);

常量日期和当前日期之间的差异(Joda)

你可以使用Days.daysBetween(jodaDate1,jodaDate2)

这里有一个例子:

        val dateTime: DateTime = DateTime.parse("14/09/2020",
            DateTimeFormat.forPattern("dd/MM/yyyy"))
        val currentDate = DateTime.now()
        //To calculate the days in between
        val dayCount = Days.daysBetween(dateTime,currentDate).days
        //Set Value to TextView 
        binding.daysCount.text = dayCount.toString()

DateTime  dt  = new DateTime(laterDate);        

DateTime newDate = dt.minus( new  DateTime ( previousDate ).getMillis());

System.out.println("No of days : " + newDate.getDayOfYear() - 1 );    

令人恼火的是，withTimeAtStartOfDay答案是错误的，但只是偶尔错误。你想要的:

Days.daysBetween(start.toLocalDate(), end.toLocalDate()).getDays()

事实证明，“午夜/一天的开始”有时意味着凌晨1点(夏令时在某些地方是这样发生的)。daysBetween不能正确处理。

// 5am on the 20th to 1pm on the 21st, October 2013, Brazil
DateTimeZone BRAZIL = DateTimeZone.forID("America/Sao_Paulo");
DateTime start = new DateTime(2013, 10, 20, 5, 0, 0, BRAZIL);
DateTime end = new DateTime(2013, 10, 21, 13, 0, 0, BRAZIL);
System.out.println(daysBetween(start.withTimeAtStartOfDay(),
                               end.withTimeAtStartOfDay()).getDays());
// prints 0
System.out.println(daysBetween(start.toLocalDate(),
                               end.toLocalDate()).getDays());
// prints 1

通过LocalDate可以避免整个问题。