Henry
Thanks for the reply.
I use the same static xml data DOM tree for
transformations in different threads.
Are you suggesting that I need to synchronize the read
access to this data DOM tree for transformation from
different threads?
Thanks
Kumar
--- Henry Zongaro <[EMAIL PROTECTED]> wrote:
> Hi, Kumar.
>
> Kumar Pandey <[EMAIL PROTECTED]> wrote on
> 2005-06-05 04:39:39 PM:
> > jdk :1.5.0_02-b09
> > xalan: 2.6.0
> >
> > I'm creating a static template using
> > TransformerFactory.newTemplates().
> > creation block is synchronized as it gets called
> in a
> > servlet.
> >
> > Then for each web request I create a new
> Transformer
> > like so -
> >
> > transformerForARequest =
> > staicTemplateInstance.newTransformer();
> >
> > Then I proceed with the transformation on xml
> data.
> ...
> > java.lang.NullPointerException
> > at
> >
>
org.apache.xml.dtm.ref.dom2dtm.DOM2DTM.addNode(DOM2DTM.java:237)
> > at
> >
>
org.apache.xml.dtm.ref.dom2dtm.DOM2DTM.nextNode(DOM2DTM.java:539)
> > at
>
> It looks like the NullPointerException is being
> thrown from the
> following piece of code - the line that checks
> whether name equals or
> begins with "xmlns".
>
> if (Node.ATTRIBUTE_NODE == type)
> {
> String name = node.getNodeName();
>
> if (name.startsWith("xmlns:") ||
> name.equals("xmlns"))
> {
> type = DTM.NAMESPACE_NODE;
> }
> }
>
>
> It looks like the call to getNodeName() for an
> attribute node has
> returned null. Is the same tree used a input for
> more than one
> transformation at the same time? The DOM
> specification requires
> multi-threaded access (even read access) to a DOM
> tree to be synchronized.
> If each thread transforms its own DOM tree, how is
> the DOM tree created?
> Is it possible that the fault lies there? Does the
> processor always throw
> the NPE from the same line in DOM2DTM?
>
> Thanks,
>
> Henry
>
------------------------------------------------------------------
> Henry Zongaro Xalan development
> IBM SWS Toronto Lab T/L 969-6044; Phone +1 905
> 413-6044
> mailto:[EMAIL PROTECTED]
>
>
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