Monday, April 9, 2012

Simple trick to convert Date format with timezone in Java!

I am sure most of you got frustrated from the fact that SimpleDateFormat can not handle ISO8601 format. Here is my little trick to solve this nuisance.

Create a list of Know format you know that you will use for your application and apply SimpleDateFormat to the list. Now, in your formatDate() method, simply try all your known format and trap the Exception, then if still did not have a date, just use javax.xml.bind.DatatypeConverter.parseDateTime(date) to try it and see if that work.

Here is my

package org.cnci.util;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
public abstract class DateUtils {
    // XML formater: this only for converting date into XML string
    private static final SimpleDateFormat xmlFormater = 
                           new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
    // define all known date formats
    private static final SimpleDateFormat[] allFormats = new SimpleDateFormat[] {
        //new SimpleDateFormat("MM/dd/yyyy hh:mm:ss.SSS a"),
        new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ"), // XSD 
        new SimpleDateFormat("MM/dd/yyyy HH:mm:ssZ"), // Oracle
        new SimpleDateFormat("EEE MMM d HH:mm:ss z yyyy"), 
        new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z"), // rfc822
        new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.US), 
        new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss"), // XSD
        new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS"), 
        new SimpleDateFormat("MM/dd/yyyy HH:mm:ss.SSS"),
        new SimpleDateFormat("MM/dd/yyyy HH:mm:ss"), // Oracle
        new SimpleDateFormat("dd.MM.yyyy HH:mm:ss"),
        new SimpleDateFormat("yyyy.MM.dd G 'at' HH:mm:ss z"),
        new SimpleDateFormat("yyyy.MM.dd GGG hh:mm aaa"),
        new SimpleDateFormat("yy-MM-dd HH:mm:ss.SSS"),
        new SimpleDateFormat("M/d/yyyy hh:mm:ss"), 
        new SimpleDateFormat("M/d/yyyy hh:mm a"), 
        new SimpleDateFormat("M/d/yy hh:mm:ss"), 
        new SimpleDateFormat("M/d/yy hh:mm a"),
        new SimpleDateFormat("M/d/yy HH:mm"),
        new SimpleDateFormat("M/d/yyyy HH:mm"),
        new SimpleDateFormat("M-d-yy HH:mm"), 
        new SimpleDateFormat("M-d-yyyy HH:mm"), 
        new SimpleDateFormat("M/d/yy"), 
        new SimpleDateFormat("M/d/yyyy"), 
        new SimpleDateFormat("M-d-yy"),
        new SimpleDateFormat("M-d-yyyy"), 
        new SimpleDateFormat("MMMM d, yyyyy"), 
        new SimpleDateFormat("MMM d, yyyyy") 
    public static Date parseDate(final String date) throws ParseException {
        if (isEmptyString(date))
            throw new ParseException("Error: date is null or empty!", 0);
        // iterate over the array and parse
        Date myDate = null;
        if (date.endsWith("Z")) {
            myDate = parseXMLDate(date);
        if (myDate == null) {
            for (DateFormat df : allFormats) {
                try {
                    myDate = df.parse(date);
                    return myDate;
                catch (Exception e) {
                    // do nothing because we want to try the next
                    // format if current one fails
            if (myDate == null) {
                myDate = parseXMLDate(date);
            // nothing returned so couldn't parse
            if (myDate == null) throw new ParseException("Error: unable to parse date: " + date, 0);
        return myDate;
    //Use the JAXB data type conversion, since it already know the xml valid date format
    private static java.util.Date parseXMLDate(final String date) {
        Calendar cal = javax.xml.bind.DatatypeConverter.parseDateTime(date);
        return cal.getTime();
    //convert to the string representation of the datetime format
    //NOTES: this should be the same as formatDate() but keep 
    // and preferred to use this one instead.  Just in case the JAXB
    // document DatetypeConverter change in the future.
    public static String formatXMLDate(final java.util.Date date) {
        Calendar cal = Calendar.getInstance();
        return javax.xml.bind.DatatypeConverter.printDateTime(cal);
    // should yield the same results as formatXMLDate() method above.
    public static String formatDate(final java.util.Date date) {
        return xmlFormater.format(date);
    public static boolean isEmptyString(String str)
        if (str == null) return true;
        return "".equals(str.trim());

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