Ontology Plugin problem

["McGibbney, Lewis John" <Le...@gcu.ac.uk>]

Hello list,

I apologies in advance for the rather large post.

Using Nutch-1.2
Tomcat 6.0.26

I attempted to get this working a while ago and I am now back to ask for advice when using this particular plugin (if anyone is using it). According to the wiki, when a search query is executed search.jsp can fail due to Tomcat and Jena using conflicting versions of the same xerces library. In my case I got the following


exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /./refine-query-init.jsp at line 34

31:   try {
32:     Configuration nutchConf = NutchConfiguration.get(application);
33:     String urls = nutchConf.get("extension.ontology.urls");
34:     ontology = new org.apache.nutch.ontology.OntologyFactory(nutchConf).getOntology();
35:     if (urls==null || urls.trim().equals("")) {
36:       // ignored siliently
37:     } else {


Stacktrace:
        org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
        org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:401)
        org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
        org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:717)


root cause

javax.servlet.ServletException: java.lang.NoClassDefFoundError: org/apache/xerces/util/XMLChar
        org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:862)
        org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:791)
        org.apache.jsp.search_jsp._jspService(search_jsp.java:886)
        org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
        org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
        org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:717)


Looking at the java.lang.NoClassDefFoundError's (as there are 3 root causes in all), I see that

XMLChar is consistent. I'm hoping that this is good news and all I need to do is update the Tomcat

Xerces library to match Jena.

Does anyone have information as to how I can do this? I have tracked down the xercesImpl.jar within

\apache-tomcat-6.0.26-windows-x86\apache-tomcat-6.0.26\webapps\nutch-1.2\WEB-INF\classes\plugins\lib-xml

but I am not sure which version this is. I am also not sure which version Jena is using!

Thank you

Lewis

Glasgow Caledonian University is a registered Scottish charity, number SC021474

Winner: Times Higher Education's Widening Participation Initiative of the Year 2009 and Herald Society's Education Initiative of the Year 2009
http://www.gcu.ac.uk/newsevents/news/bycategory/theuniversity/1/name,6219,en.html