Want to convert timezone (from any timezone to "America/Los_Angeles"(PST))

[Roopesh Rana]

Hi All,

I am working on multi country application, user can login from any country, now I need to convert my Date in PST time zone. Every time it will get user time zone and convert it into "America/Los_Angeles" (PST) time zone, and it will return date object with converted date.

@Override
	public Date deserialize(JsonParser jsonparser, DeserializationContext ctxt) throws IOException, JsonProcessingException {
		try {
			Date date = null;
			final TimeZone timeZone = new UserSession(http_request.getSession()).getTimeZone();
			SimpleDateFormat format = new SimpleDateFormat(ConfigBean.getProperty("api.format.date"));
			format.setLenient(false);
			format.setTimeZone(timeZone);
			String userDateString = jsonparser.getText();
			date = format.parse(userDateString);

			DateFormat convertedFormat = new SimpleDateFormat(ConfigBean.getProperty("api.format.date"));

			// Convert date in PST timezone
			convertedFormat.setTimeZone(TimeZone.getTimeZone("America/Los_Angeles"));
			convertedFormat.setLenient(false);
			String convertedDate = convertedFormat.format(date);
			format.setTimeZone(TimeZone.getTimeZone("America/Los_Angeles"));
			date = format.parse(convertedDate);
			
			logger.error("Temp Logger added: " + jsonparser.getText() + "converted to " + date);
			return date;
		} catch (Exception e) {
			logger.error("Fatal failure during JSON Date Deserialization.", e);
			throw new JsonGenerationException("Unexcpected exception during JSON Deserialization.", e);
		}

Please help.

Regards,
Roopesh

[K. Tsang]

So what problem are you facing? Does the code work?

[Roopesh Rana]

No, this code not working, it is returning IST But I need PST time zone

[Dave Tolls]

There may be other problems, but the main thing I see is that Date doesn't have a Timezone associated with it.
It's always milliseconds from the Epoch.
The display format used determines what TimeZone you see.

[Roopesh Rana]

I got some thing, but this is also giving wrong result,

 Calendar currentdate = Calendar.getInstance();
            String strdate = null;
            DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
            formatter.setLenient(false);
            strdate = formatter.format(currentdate.getTime());
            TimeZone obj = TimeZone.getTimeZone("PST");

            formatter.setTimeZone(obj);
            //System.out.println(strdate);
            //System.out.println(formatter.parse(strdate));
            Date theResult = formatter.parse(strdate);
          
            System.out.println("The current time in India is  :: " +currentdate.getTime());

            System.out.println("The date and time in :: "+ obj.getDisplayName() + "is ::" + theResult);

[Dave Tolls]

Roopesh Rana wrote:I got some thing, but this is also giving wrong result,

If the thing that is incorrect is 'theResult' then, again, it is a Date object, which has no concept of Timezone.
When you print out a Date it is formatted based on your systems Timezone by default.

[Roopesh Rana]

Through this you can achieve date in different timezone

public static void main(String[] args) {
		// TODO Auto-generated method stub
		DateTime dateTimeUserTime = new DateTime("2015-03-21T05:00:00", DateTimeZone.forID("Asia/Karachi"));
		dateTimeUserTime.toLocalDateTime();
		dateTimeUserTime.toDateTime(DateTimeZone.forID("Asia/Calcutta")).toDate();
	}

[Jesper de Jong]

Now you are using the DateTime class, which is from the Joda Time library (?), instead of java.util.Date.

Joda Time's DateTime class does have timezone information, in contrast to java.util.Date.

Note that lines 4 and 5 really have no effect, since you're not doing anything with the return values of the methods that you are calling.

When you convert the DateTime to a jav.util.Date in line 5, you will lose the timezone information again (simply because java.util.Date does not store this information), so this doesn't really help you anything.