Strange behavior of java.text.DateFormat

[Chaitanya Brahma]

Hi Ranchers,

I have come across a real strange behavior of the class java.text.DateFormat. The code listed below executes properly on one Eclipse environment but gives "java.text.ParseException: Unparsable date" on another one!

Can anyone please throw some light as to what could be the possible issue here?

Thanks a ton in advance!

The code in question is as listed below -

   
package org.remede.ActivityTracker.test;

import java.text.DateFormat;
import java.text.ParseException;

//import java.util.Calendar;

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
//		Double db = new Double(1);
		
		String dtstring = "JUNE 10, 2009";
		DateFormat format = DateFormat.getDateInstance(DateFormat.MEDIUM);
		java.util.Date dt;
		try {
			dt = format.parse(dtstring);
			System.out.println("date: " + dt);
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}

Exception I get :

    
java.text.ParseException: Unparseable date: "JUNE 10, 2009"
	at java.text.DateFormat.parse(DateFormat.java:337)
	at org.remede.ActivityTracker.test.Test.main(Test.java:20)

[Maneesh Godbole]

Try with Jun 10, 2009. Notice the Jun instead of June

[Jesper de Jong]

I'm surprised that it works at all. The reason why this may or may not work depends on what version of Java you use, what the locale setting is and possibly other factors.

Looking at this line:

DateFormat format = DateFormat.getDateInstance(DateFormat.MEDIUM);

Format specifiers such as DateFormat.MEDIUM are really not meant to be used for parsing, but only for formatting dates. The Java API documentation does not even explain in detail what the format is when you use DateFormat.MEDIUM, so if you use this for parsing, you don't know what strings will be accepted and what will be rejected.

You'd better use SimpleDateFormat for parsing date strings, so that you can specify the format yourself, for example:

DateFormat format = new SimpleDateFormat("MMMM dd, yyyy");

I don't know if this accepts all uppercase letters for the month name, such as "JUNE" in your example. See the documentation of SimpleDateFormat for more information on how to specify the format string.

[Chaitanya Brahma]

Hi Jesper,

Thanks a lot for your quick and important input. The problem was resolved using SimpleDateFormat.

Thanks again,
bchaitanya