Simple manipulation of Java timestamp object?

Question

I'm trying to do some simple client side date manipulation in Java. It's stored in UTC down to the millisecond, but for client side display I would like to truncate it to the second and display it in PST.

Currently, I'm getting the time from the db as a string like so:

    myDataSet.someDate = resultSet.getString("some_date"));

I was thinking that I get some sort of Time object, manipulate it so it displays in the format I want and then wrap it in a string for display purposes. Here's what I have so far.

    myDataSet.someDate = String.valueOf(resultSet.getTimestamp("some_date"));

This gets me the string, but the time is not in the correct form. I've found a few answers, but they all seem to want me to write another function. This seems like something I should be able to do in one line of code.

See [`SimpleDateFormat`](http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html) and any [example usage](http://stackoverflow.com/questions/9872419/converting-string-to-date-using-simpledateformat). — maerics, May 27 '14 at 18:16

score 1 · Answer 1 · edited May 27 '14 at 18:31

The following code takes a Calendar object, makes a Date object out of it, and formats it into a readable String.

Calendar cal = new GregorianCalendar();
cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
Date s = new Date(cal.getTimeInMillis());
SimpleDateFormat sdf = new SimpleDateFormat("EEE, d MMM yyyy");
String formatted = sdf.format(s);

This returns something like:
Tue, May 27, 2014

score 0 · Answer 2 · answered May 27 '14 at 18:28

Date formatting in Java is a terrible pain, so it is unlikely that you will find a one-liner. However, you should be able to use a SimpleDateFormat like so (untested):

String format = "yyyy-MM-dd HH:mm z"; // <-- change as needed
DateFormat formatter = new SimpleDateFormat(format);
Timestamp timestamp = resultSet.getTimestamp("some_date");
String dateString = formatter.format(new java.util.Date(timestamp.getTime()));

score 0 · Accepted Answer · edited May 29 '14 at 08:14

I decided to use Joda-Time. It seemed to offer more complete functionality than anything native.

DateTime date = DateTime.parse(myDataSet.getString("some_date"), DateTimeFormat.forPattern("yy-MM-dd HH:mm:ss.SSS"));
myDataSet.someDate = date.toString("dd-MMM-yy HH:mm:ss");

This converts my string to a Joda DateTime object and then reformats it. Still working on a good way to convert UTC to PST while accounting for offset besides .minusHours, but it seems like the functionality is there.

Simple manipulation of Java timestamp object?

3 Answers3