Tag Archives: tag converters

ATG Date Tag Converter is Buggy

Posted on by
Reply

Leaf on my car on Flickr

(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.

<dsp:valueof param=”creationDate” converter=”date” date=”M/dd/yyyy”/>

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.

ATG Currency Converter Not Working With JSTL c:set

Posted on by
Reply

Currency conversion confusion on Flickr!

This JSP code was not outputting the properly formatted amount.

<dspel:valueof value="${dollars}" converter="currency" />

I tried forcing it by specifying the conversion parameters.

<dspel:valueof value="${dollars}" converter="currency" locale="en-CA" format="#.00" currency="$" />

I then debugged atg.droplet.CurrencyTagConverter using Eclipse and found this code being executed.

public String convertObjectToString(DynamoHttpServletRequest pRequest,
                                 Object pValue, Properties pAttributes)
  throws TagConversionException
{
  if ((pValue == null) || (pValue instanceof String))
    return (String)pValue;

It turns out pValue was a String which is why it was never being formatted.  But why is it a String?

Well the code that sets dollars looks like this.

<dspel:tomap var="paymentGroup" param="commerceItem.paymentGroups[1]" />
<c:set var="dollars" value="0" />
<c:if test="${not empty paymentGroup}">
  <c:set var="dollars" value="${paymentGroup.amount}" />
</c:if>

Apparently c:set converts the Double to a String.

To work around this problem I did this.

$<dspel:valueof number="0.00" value="${dollars}" />

For further reading please see Tag Converters in the ATG Page Developer’s Guide.