Question

This question is a duplicate of this question by intention. It seems like the older one is “ignored”, while none of the answers there is the answer.

I need to parse a given date with a given date pattern/format.

I have this code, which is supposed to work:

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class Main
{

    public static void main(String[] args)
    {
        final Date date = string_to_date("EEE MMM dd HH:mm:ss zzz yyyy",
                "Thu Aug 14 16:45:37 UTC 2011");
        System.out.println(date);
    }

    private static Date string_to_date(final String date_format,
            final String textual_date)
    {
        Date ret = null;

        final SimpleDateFormat date_formatter = new SimpleDateFormat(
                date_format);
        try
        {
            ret = date_formatter.parse(textual_date);
        }
        catch (ParseException e)
        {
            e.printStackTrace();
        }

        return ret;
    }
}

For some reason I’m getting this output:

java.text.ParseException: Unparseable date: "Thu Aug 14 16:45:37 UTC 2011"
    at java.text.DateFormat.parse(DateFormat.java:337)
    at Main.string_to_date(Main.java:24)
    at Main.main(Main.java:10)
null

What’s wrong with my date pattern? This seems to be a mystery.

Answer 1

Your platform default locale is apparently not English. Thu and Aug are English. You need to explicitly specify the Locale as 2nd argument in the constructor of SimpleDateFormat:

final SimpleDateFormat date_formatter = 
    new SimpleDateFormat(date_format, Locale.ENGLISH); // <--- Look, with locale.

Without it, the platform default locale will be used instead to parse day/month names. You can learn about your platform default locale by Locale#getDefault() the following way:

System.out.println(Locale.getDefault());