Java EE (Java Enterprise Edition) General Discussion

I have several JSP's I wanted to add logging to, so I changed the following:

web.xml - added the entry:

 <jsp-config>
     <taglib>
         <taglib-uri>http://jakarta.apache.org/taglibs/log-1.0</taglib-uri>
          <taglib-location>/WEB-INF/tld/taglibs-log.tld</taglib-location>
     </taglib>
 </jsp-config>

in WEB-INF/classes I put log4j.xml and log4j.dtd
in WEB-INF/tld I put taglibs-log.tld

and in my JSP added the following entries - just to test that it works:

<%@ taglib uri="http://jakarta.apache.org/taglibs/log-1.0" prefix="log" %>

....

<log:debug>I am in page: home.jsp</log:debug>

Then, when I started the server from Eclipse, I navigated to the JSP and got the following error:

500 Servlet Exception

[show] java.lang.SecurityException: class "org.apache.log4j.Category"'s signer

information does not match signer information of other classes in the same
package

Could someone please tell me what I am doing wrong?