Date Parsing Issue...

[Somnath Mallick]

Hi Everyone,

I have a date which of the format "15-Dec-2009 06:13:14" enetered by the user as String. I want to convert it to Date format (java.util.Date). But i am getting the error as unable to parse in my code.

try
{
        DateFormat dateFormat = new SimpleDateFormat("DD-MM-YYYY HH:MM:SS");
	Date time = dateFormat.parse(timeStamp);
}
catch (ParseException parseException) 
{
	System.out.println("Unable to recognize the date entered! Illegal format.");
	parseException.printStackTrace();
}

Error Stack:

java.text.ParseException: Unparseable date: "15-Dec-2009 06:13:14 "
	at java.text.DateFormat.parse(DateFormat.java:337)
	at com.techm.bt.b2b.or.jupiter.createLogs.LogCreator.createLogs(LogCreator.java:126)
	at com.techm.bt.b2b.or.jupiter.takeInput.UserConsole.main(UserConsole.java:41)

[Christophe Verré]

The first thing striking my eyes is that you're using MM for both months and minutes You need to read carefully the java.text.SimpleDateFormat API.

[Jesper de Jong]

The codes you use to specify the date format when you create a SimpleDateFormat object are case-sensitive. So "DD-MM-YYYY HH:MM:SS" doesn't mean what you think it means. Lookup the documentation for SimpleDateFormat for information on how to specify the format.

Also, the "MM" you use for the months is not going to match three-letter month abbreviations like "Dec".

[Somnath Mallick]

I modified the code after going through the API.

DateFormat dateFormat = new SimpleDateFormat("dd-mmm-yyyy HH:MM:SS");
Date time = dateFormat.parse(timeStamp);

Now I get the error as:

java.text.ParseException: Unparseable date: "14-Dec-2009 17:00:00 "
	at java.text.DateFormat.parse(DateFormat.java:337)
	at com.techm.bt.b2b.or.jupiter.createLogs.LogCreator.createLogs(LogCreator.java:123)
	at com.techm.bt.b2b.or.jupiter.takeInput.UserConsole.main(UserConsole.java:41)

Also i checked the API and found that 14-Dec-2009 17:00:00 type of date is not mentioned anywhere!

[Somnath Mallick]

Got it after a little further reading and experiments. This worked for me! Thanks!

DateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy HH:MM:SS");
Date time = dateFormat.parse(timeStamp);

[Jesper de Jong]

Somnath Mallick wrote:Got it after a little further reading and experiments. This worked for me! Thanks!

DateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy HH:MM:SS");
Date time = dateFormat.parse(timeStamp);

Are you sure that this works correctly? Note that MM (upper-case) is the month number, not minutes, and SS (upper-case) is milliseconds, not seconds.

[Somnath Mallick]

^^Well at least, Well do you mean to say that i should change it like this?

DateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy hh:mm:ss"); 

Also one more question, Lets for example take the code:

if (time.after(InputBean.getSearchStartTimeStamp()) && time.before(InputBean.getSearchEndTimeStamp()))
{
	String errorDetails = errorLine.substring(errorLine.lastIndexOf("<"), errorLine.lastIndexOf(">"));
	System.out.println("Error Details: " + errorDetails);
}

time is in GMT.
InputBean.getSearchStartTimeStamp() and InputBean.getSearchEndTimeStamp() are in IST.
Will they yield a proper result? I mean does JVM does the IST to GMT conversions internally?

[Ulf Dittmer]

I mean does JVM does the IST to GMT conversions internally?

No. The Date class has no notion of timezones; you'll need to use the Calendar class instead.

[Somnath Mallick]

I modified the code to this:

SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy hh:mm:ss");
Calendar calendar = Calendar.getInstance(new SimpleTimeZone(0, "GMT"));
dateFormat.setCalendar(calendar);
Date time = dateFormat.parse(timeStamp);

System.out.println("Time: " + time.toString());

But still all the dates are printing in IST!

[Ulf Dittmer]

As I said before, the Date class has no concept of timezones, therefore Date.toString is not likely to do the right thing. Use DateFormat.format instead, and make sure to set its timezone (which the code currently is not doing).

[Jesper de Jong]

Somnath Mallick wrote:^^Well at least, Well do you mean to say that i should change it like this?

DateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy hh:mm:ss"); 

Yes, but note that hh (lower-case) for the hours means the hour in AM/PM (1-12) - this will fail if hours is 17. Try this:

DateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss"); 

Somnath Mallick wrote:But still all the dates are printing in IST!

Yes, because Date.toString() uses the local timezone setting of your system - it displays the Date object in your local timezone. Instead of using Date.toString(), format the date object using a DateFormat object; set the timezone that you want your date displayed in on the DateFormat object. As Ulf said, class Date itself doesn't know about timezones.

[Somnath Mallick]

SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss");
Calendar calendar = Calendar.getInstance(new SimpleTimeZone(0, "GMT"));
dateFormat.setCalendar(calendar);
Date time = dateFormat.parse(timeStamp);
						
System.out.println("Time: " + dateFormat.format(time));

I hope this is correct? But when the time is printing no time zone is getting printed so i cant really say the times are really in GMT or IST.
Also when i am trying to insert this value in an excel sheet using POI API, i had to convert all time values to string, so all the data entered in the Excel sheet is IST!