Dateformatter in java

Question

I am using the below code to format millisecond resolution date strings. It works for 2018-09-14T13:05:21.329Z but not 2018-09-14T13:05:21.3Z. Can anybody suggest the reason and how to correct it?

DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX");
SimpleDateFormat sdfDestination = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try {
    Date parsedDate = formatter.parse(date);
    String destDate = sdfDestination.format(parsedDate);
    return destDate;
} catch (java.text.ParseException parseException) {
    logger.error("Parse Exception occured while converting publication time to date "
            + "format 'yyyy-MM-dd HH:mm:ss'", parseException);
}

I get below exception:

java.text.ParseException: Unparseable date: "2018-09-14T13:05:21.3Z"
    at java.text.DateFormat.parse(Unknown Source) ~[na:1.8.0_181]
    at com.noordpool.api.implementation.utility.Utility.parseDate(Utility.java:136) [classes/:na]
    at com.noordpool.api.implementation.utility.Utility.parseMessage(Utility.java:77) [classes/:na]

Answer 1

Your only problem is that you are using a wrong pattern for SimpleDateFormat, you need to change:

DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX");

To:

DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");

Because the Z used in the date string means "zero hour offset" so you just need to pass it as 'Z' in your pattern.

This is a working demo with the right pattern.

Edit:

And to make things work with different Locales and Timezones, you need to use the appropriate Locale when you are creating the SimpleDateFormat instance, this is how should be the code:

DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US);