Taglib Sample Working, But Copy Does Not. Why?

[Elisa Green <el...@sheridanc.on.ca>]

New user here.

I have a sample dbtag taglib sample that works.  This sample was
working a month ago and the tomcat server that I use has been
modified a few times since then in minor ways.  When I change the
name of the working file, it does not work.  If I change the name
back, it works again.  However, if I copy this working sample
with the same permissions and to the same directory, the copy
does not work.  If I change the name of the copy to the same name
as the original, it does not work.

Does this has something to do with my CLASSPATH?  If so, why does
the original one still work?

This is the error that I get:
---------------------------

Error: 500

Location: /etest/catalog/mySQLtaglib_test.jsp

Internal Servlet Error:

javax.servlet.ServletException
        at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:399)
        at
javax.servlet.http.HttpServlet.service(HttpServlet.java:865)
        at
org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404)
        at
org.apache.tomcat.core.Handler.service(Handler.java:286)
        at
org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
        at
org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:797)
        at
org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
        at
org.apache.tomcat.service.connector.Ajp12ConnectionHandler.processConnection(Ajp12ConnectionHandler.java:166)
        at
org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
        at
org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498)
        at java.lang.Thread.run(Thread.java:484)

Root cause: 

java.lang.NoSuchMethodError
        at
org.apache.jasper.compiler.TagLibraryInfoImpl.createAttribute(TagLibraryInfoImpl.java:524)
        at
org.apache.jasper.compiler.TagLibraryInfoImpl.createTagInfo(TagLibraryInfoImpl.java:432)
        at
org.apache.jasper.compiler.TagLibraryInfoImpl.parseTLD(TagLibraryInfoImpl.java:385)
        at
org.apache.jasper.compiler.TagLibraryInfoImpl.(TagLibraryInfoImpl.java:233)
        at
org.apache.jasper.compiler.JspParseEventListener.handleDirective(JspParseEventListener.java:706)
        at
org.apache.jasper.compiler.DelegatingListener.handleDirective(DelegatingListener.java:116)
        at
org.apache.jasper.compiler.Parser$Directive.accept(Parser.java:215)
        at
org.apache.jasper.compiler.Parser.parse(Parser.java:1077)
        at
org.apache.jasper.compiler.Parser.parse(Parser.java:1042)
        at
org.apache.jasper.compiler.Parser.parse(Parser.java:1038)
        at
org.apache.jasper.compiler.Compiler.compile(Compiler.java:182)
        at
org.apache.jasper.servlet.JspServlet.doLoadJSP(JspServlet.java:462)
        at
org.apache.jasper.servlet.JasperLoader12.loadJSP(JasperLoader12.java:146)
        at
org.apache.jasper.servlet.JspServlet.loadJSP(JspServlet.java:433)
        at
org.apache.jasper.servlet.JspServlet$JspServletWrapper.loadIfNecessary(JspServlet.java:152)
        at
org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:164)
        at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:318)
        at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:391)
        at
javax.servlet.http.HttpServlet.service(HttpServlet.java:865)
        at
org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404)
        at
org.apache.tomcat.core.Handler.service(Handler.java:286)
        at
org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
        at
org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:797)
        at
org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
        at
org.apache.tomcat.service.connector.Ajp12ConnectionHandler.processConnection(Ajp12ConnectionHandler.java:166)
        at
org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
        at
org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498)
        at java.lang.Thread.run(Thread.java:484)