Simple Java 7 RFC3339 parser (Android compatible)

DateUtil.java

/*
Inspired by http://cokere.com/RFC3339Date.txt
All rights deserve to Chad Okere
*/

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

public class DateUtil {
    /*
        Values tested :
        "2007-05-01T15:43:26+07:00"
	"2007-05-01T15:43:26.3+07:00"
    	"2007-05-01T15:43:26.3452+07:00"
	"2007-05-01T15:43:26-07:00"
	"2007-05-01T15:43:26.3-07:00"
    	"2007-05-01T15:43:26.3452-07:00"
    	"2007-05-01T15:43:26.3452Z"
    	"2007-05-01T15:43:26.3Z"
    	"2007-05-01T15:43:26Z"
     */

    public synchronized static Date parseRFC3339Date(String dateString) throws java.text.ParseException, IndexOutOfBoundsException {
        Date d;

        //if there is no time zone, we don't need to do any special parsing.
        if (dateString.endsWith("Z")) {
            try {
                SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.getDefault());//spec for RFC3339 with a 'Z'
                s.setTimeZone(TimeZone.getTimeZone("UTC"));
                d = s.parse(dateString);
            } catch (java.text.ParseException pe) {//try again with optional decimals
                SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSSSS'Z'", Locale.getDefault());//spec for RFC3339 with a 'Z' and fractional seconds
                s.setTimeZone(TimeZone.getTimeZone("UTC"));
                s.setLenient(true);
                d = s.parse(dateString);
            }
            return d;
        }

        //step one, split off the timezone.
        String firstPart;
        String secondPart;
        if (dateString.lastIndexOf('+') == -1) {
            firstPart = dateString.substring(0, dateString.lastIndexOf('-'));
            secondPart = dateString.substring(dateString.lastIndexOf('-'));
        } else {
            firstPart = dateString.substring(0, dateString.lastIndexOf('+'));
            secondPart = dateString.substring(dateString.lastIndexOf('+'));
        }

        //step two, remove the colon from the timezone offset
        secondPart = secondPart.substring(0, secondPart.indexOf(':')) + secondPart.substring(secondPart.indexOf(':') + 1);
        dateString = firstPart + secondPart;
        SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.getDefault());//spec for RFC3339
        try {
            d = s.parse(dateString);
        } catch (java.text.ParseException pe) {//try again with optional decimals
            s = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ", Locale.getDefault());//spec for RFC3339 (with fractional seconds)
            s.setLenient(true);
            d = s.parse(dateString);
        }
        return d;
    }
}

This breaks in line 32 on date strings with a positive timezone offset which is perfectly valid according to RFC 3339.

Eg. 2016-03-13T17:20:24+00:00

@liminal I've updated the gist to support + time zones.
Thanks.

Test results : http://ideone.com/DW4vDg

For Java8, can directly use java.time.format.DateTimeFormatter.ISO_OFFSET_DATE_TIME

Thank you for the code snippet. It's really helpful.
Would you consider a Kotlin version?

@anticafe Sorry but I'm no longer using this snippet since I'm working on other projects