How to split the full date format in date and time?

Question

I have a lot of Strings in the format shown my example that I have to parse. I'm trying to determine which of the Strings are today.

My problem is, that the time is almost there and I just need to compare that date.

Next I want to check if time is between two timestamps "HH:mm:ss" with .after and .before, but there is the problem, that the date is almost there.

How do I split that parsed format in date and time to handle each in its own way?

I'm working in Android Studio, if that's relevant.

String dtStart = "2016-05-23 07:24:59";
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

try {

     if (new Date().equals(format.parse(dtStart)) ) System.out.println("true");
     else System.out.println("false");

     list.add(new LatLng(lat, lng));

} catch (java.text.ParseException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
}

Answer 1

java.time

Use the java.time classes built into Java 8 and later.

Much of the functionality has been back-ported to Java 6 & 7 in ThreeTen-Backport , and further adapted to Android in ThreeTen-ABP .

String dateToParse = "2016-05-23 07:24:59";
LocalDateTime dateTime = LocalDateTime.parse(dateToParse, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
LocalDate localDate = dateTime.toLocalDate();
LocalTime localTime = dateTime.toLocalTime();
// Compare here to your date & time

Answer 2

You can easily achieve it by using the SimpleDateFormat like that:

//Houres - seconds
SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm:ss");
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");

//Years - days
Date hoursAndMinutes = timeFormat.parse(dtStart);
Date yearsMonthsDays = dateFormat.parse(dtStart);

That way, you only get the hours, minutes and seconds of your date. Then, you can do the same for just the year and month and compare it afterwards.

Answer 3

And just to be complete, here's how you'd do it using the Joda date time library and the toLocalDate() and toLocalTime() method.

DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss");
DateTime today = new DateTime();
DateTime start = formatter.parseDateTime(dtStart);
if (today.toLocalDate().compareTo(start.toLocalDate()) != 0) {
    System.out.println("true");
} else {
    System.out.println("false");
}

if (today.toLocalTime().compareTo(start.toLocalTime()) > 0) {
...
}

Answer 4

thx for help and sry i forgot to say i'm on android studio..

i found my solution here: https://docs.oracle.com/javase/7/docs/api/java/text/DateFormat.html

String dtStart = "2016/05/23 07:24:59";
SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

try {
      Date dtStartOK = format.parse(dtStart);
      String stringDate = DateFormat.getDateTimeInstance().format(dtStartOK);
      System.out.println(stringDate);

      System.out.println(DateFormat.getDateInstance().format(dtStartOK));
      System.out.println(DateFormat.getTimeInstance().format(dtStartOK));

} catch (ParseException e) {
      //Handle exception here, most of the time you will just log it.
      e.printStackTrace();
}

gives me:

23.05.2016 07:24:59

23.05.2016

07:24:59