Convert Java String in ISO timestamp format to SimpleDateFormat

I am trying to convert a String in ISO timestamp format to a SimpleDateFormat like so:

public static void convertDate () {
   String timestamp = DateFormatUtils.ISO_DATETIME_TIME_ZONE_FORMAT.format(new Date());
   DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZZ");
   Date date = (Date)formatter.parse(timestamp);  
 }
 

The above code throws the following exception:

java.text.ParseException: Unparseable date:
 

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