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DWR, Tomcat 5.5, and Xalan classpath error

If you get errors attemtping to use DWR with Tomcat 5.5+ with a stack trace similiar to:

342192658 [http-8080-Processor3] ERROR org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/Ajax] - StandardWrapper.Throwable
javax.xml.transform.TransformerFactoryConfigurationError: Provider org.apache.xalan.processor.TransformerFactoryImpl not found
at javax.xml.transform.TransformerFactory.newInstance(Unknown Source)

It is due to an issue with the xml-apis.jar that Tomcat includes in the common/endorsed directory (which is also in the tomcat classpath by default). This jar conflicts with the javax call attempted seen in the stack trace. I renamed xml-apis.jar to .bak and restarted, which solved the problem, but you could probably also just remove /common/endorsed from the startup script. I’m not sure if Tomcat needs either of the jars in this folder for its own work, but so far things seem to work fine.

Thanx………..!

thanks!!

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If you are have no access to Tomcat directories just add xalan jar to your compilation: http://xml.apache.org/xalan-j/

[...] �考文献： DWR, Tomcat 5.5, and Xalan classpath error [...]

Great info. Thanks!

Thanks! That did the trick…

Really, Thanks!!!!!!!!!

Even better, remove the package altogether:

yum remove xml-commons-apis

It has no dependencies declared. HOWEVER, (re)starting Tomcat will elicit whinings:

[root@tardis dnld]# /etc/init.d/tomcat5 restart
Stopping tomcat5: [ OK ]
Starting tomcat5: /usr/bin/rebuild-jar-repository: error: Could not find xml-commons-apis Java extension for this JVM
/usr/bin/rebuild-jar-repository: error: Some detected jars were not found for this jvm
[ OK ]

Don’t be moved: so far I haven’t seen any adverse effect — and Xalan is back!

BTW, my case was unrelated to DWR: I was running Nutch on RHEL5 and the Sun jdk1.6.0_02 .