OpenSAML with Spring on Weblogic and Java Core JSTL issue

There is a good example to start with here by Jim Cox http://sourceforge.net/projects/spring-saml/, so kudos to him.

I could strightaway get started with Spring + OpenSAML on Mavan & Tomcat.

However when it comes to getting making my own web app work on WLS 9.2+ server had various issues but mostly due to JAXP and JSTL (indirectly xml-apis-xxx) JARs conflicts on Weblogic.

If you are not using Mavan then you mainly need to add following to your WEB-INF/lib (apart from other standar jars & as per your requirement);

opensaml-2.4.1.jar
openws-1.4.1.jar
xmltooling-1.3.1.jar
resolver-2.8.0.jar
xercesImpl-2.8.0.jar
xml-apis-2.8.0.jar
And slf4j-xxx + log4j

Since I run other apps, I had to set <prefer-web-inf-classes>true</prefer-web-inf-classes> in weblogic.xml to make sure that my app web-inf/lib gets the preference.

Still I faced issue as web app JSPs use tlds core tlds like http://java.sun.com/jsp/jstl/core and I got conflicts with Weblogic JAR, suspect due to xml-apis;

<17-Feb-2012 00:39:17 o'clock GMT> <Error> <HTTP> <BEA-101017> <[weblogic.servlet.internal.WebAppServletContext@12a4caf - appName: 'samlsp', name: 'samlsp', context-path: '/samlsp'] Root cause of ServletException.weblogic.servlet.jsp.CompilationException: Failed to compile JSP /home.jsp
home.jsp:1:1: The validator class: "org.apache.taglibs.standard.tlv.JstlCoreTLV" has failed with the following exception:"java.lang.ClassCastException: weblogic.xml.jaxp.RegistrySAXParserFactory".

Same web app works like a charm in Tomcat, no problem at all.

To fix this I had to pre-compile JSPs by setting following in weblogic.xml & that cures the odd Javelin9 JSP compiler error;

      <jsp-param>
        <param-name>precompile</param-name>
        <param-value>true</param-value>
      </jsp-param>
      <jsp-param>
        <param-name>precompile-continue</param-name>
        <param-value>true</param-value>
      </jsp-param>

This works as at startup Weblogic would trigger JSP compilation first which would use Weblogic jaxp parser, later for web app class loader is set to web-inf/lib. So, technically this is a workaround.

Still, I hope Weblogic (now Oracle) gets better with package conflicts.