(Photo: Leaf on my car by exfordy)

The ATG Date Tag Converter is buggy because Java’s DateFormat is inherently unsafe for multithreaded use.  This is documented in ATG PR #123210 DateTagConverter.convertObjectToString() method is not thread safe.

You run into this problem whenever you do something like this.

Unfortunately there is no work around.  If using the Date Tag Converter is not causing problems for you, i.e you don’t see a stack trace like below, then you can ignore this bug.

2009-04-17 00:19:08,220 ERROR [nucleusNamespace.atg.dynamo.servlet.dafpipeline.DynamoServlet] java.lang.ArrayIndexOutOfBoundsException: 502
  at sun.util.calendar.BaseCalendar.getCalendarDateFromFixedDate(BaseCalendar.java:436)
  at java.util.GregorianCalendar.computeFields(GregorianCalendar.java:2081)
  at java.util.GregorianCalendar.computeFields(GregorianCalendar.java:1996)
  at java.util.Calendar.setTimeInMillis(Calendar.java:1071)
  at java.util.Calendar.setTime(Calendar.java:1037)
  at java.text.SimpleDateFormat.format(SimpleDateFormat.java:785)
  at java.text.SimpleDateFormat.format(SimpleDateFormat.java:778)
  at java.text.DateFormat.format(DateFormat.java:314)
  at atg.droplet.DateTagConverter.convertObjectToString(DateTagConverter.java:176)

But if you do see a bug like this then you might need to create a custom droplet to format the date.  The droplet should only use DateFormat instances that are not static.  I usually make my DateFormat instances local.