Failed to load or instantiate TagLibraryValidator

[Schandha Ravi]

Hi,

I'm trying to create a sample web application using JSTL. I'm using Tomcat 5.5, J2EE 1.4.

On running the app, I'm getting the exception

    
Servlet.service() for servlet jsp threw exception
java.lang.ClassNotFoundException: [B][B]org.apache.taglibs.standard.tlv.JstlCoreTLV[/B][/B]at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1363)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1209)
at org.apache.jasper.compiler.TagLibraryInfoImpl.createValidator(TagLibraryInfoImpl.java:658)
at org.apache.jasper.compiler.TagLibraryInfoImpl.parseTLD(TagLibraryInfoImpl.java:247)
        .....................

I copied both jstl.jar and standard.jar into WEB-INF/lib folder and all tlds to WEB-INF folder. In fact org.apache.taglibs.standard.tlv.JstlCoreTLV is present in the lib folder.

In one of the FAQS for JSP, it is told that keeping jstl.jar and standard.jar in classpath does not make any difference.

Please let me know, what could be the reason for the exception inspite of the availability of the class. Do I need to make any entry in web.xml?

[Bear Bibeault]

Originally posted by Schandha Ravi:
and all tlds to WEB-INF folder

What tlds? You shouldn't need to copy any tlds anywhere. Where did you get these tld files?

In one of the FAQS for JSP, it is told that keeping jstl.jar and standard.jar in classpath does not make any difference.

That is correct. The container ignores the system classpath. That's why you place the jar files in WEB-INF/lib.

Do I need to make any entry in web.xml?

No.

What URIs are you using? Is your web.xml correctly declared for servlets 2.4?
[ March 10, 2008: Message edited by: Bear Bibeault ]

[Schandha Ravi]

Hi Bear,

I downloaded a jar from Jstl Download and copied the tlds into WEB-INF folder.

I'm using the uri

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>    

in my jsp code. and my web.xml is based on following schema

    
<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee <a href="http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">" target="_blank" rel="nofollow">http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"></a>
<display-name>

[Bear Bibeault]

and copied the tlds

Again, what TLDs? There should be no TLDs copied.

[Schandha Ravi]

Hi Bear,

this time I removed all tlds , just copied the jstl.jar and standard.jar in to WEB-INF/lib folder. But still I'm getting the exception

    
SEVERE: Servlet.service() for servlet Controller threw exception
java.lang.ClassNotFoundException: org.apache.taglibs.standard.tlv.JstlCoreTLV
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1363)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1209)
at org.apache.jasper.compiler.TagLibraryInfoImpl.createValidator(TagLibraryInfoImpl.java:658)
at org.apache.jasper.compiler.TagLibraryInfoImpl.parseTLD(TagLibraryInfoImpl.java:247)
at org.apache.jasper.compiler.TagLibraryInfoImpl.<init>(TagLibraryInfoImpl.java:163)
at org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:424)
at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:493)
at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1557)
at org.apache.jasper.compiler.Parser.parse(Parser.java:127)
at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:212)
at org.apache.jasper.compiler.ParserController.parse(ParserController.java:101)
at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:156)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:296)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:277)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:265)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:564)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:302)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:679)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:461)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:399)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
at com.example.Controller.doGet(Controller.java:25)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:595)
 

[Schandha Ravi]

Hi,

Can some one please clarify me on this exception.

Thanks
Ravi

[Bear Bibeault]

Are you sure that you grabbed the JSTL 1.1 jar files?

[Schandha Ravi]

Hi Bear,

I downloaded jakarta-taglibs-standard-1.1.2 from the JSP FAQS link provided in javaranch, and copied jstl.jar and standard.jar into lib folder of WEB-INF. I have also included these jar files classpath. But no use

[Christophe Verré]

And you restarted the container ?

[Schandha Ravi]

Yes I did.

Let me put my code below, so that it would be easy for you to let me know where am I making mistake

My Servlet

    
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class Controller extends HttpServlet {
private ServletContext sctx=null;
public void init()throws ServletException{
super.init();
sctx=getServletContext();
}
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,IOException{
Collection c=new ArrayList();
HttpSession session=req.getSession(true);
c.add("Ravi");
c.add("Kota");
c.add("NTR");
c.add("ANR");
c.add("MGR");
session.setAttribute("Collection", c);
req.setAttribute("Collection", c);
sctx.log("Hi I'm in servlet");
RequestDispatcher rad=req.getRequestDispatcher("Result.jsp");
rad.forward(req,res);
}
public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException,IOException{
doGet(req,res);
}
 
}

My Results.jsp

    
<%@ page language="java" import="java.util.*" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<table border=2>
<c:forEach var="Collection" items="${sessionScope.Collection}">
<tr>
<i>${Collection}</i>
</tr>
</c:forEach>
</table>
 
</body>
</html>

web.xml

    
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee <a href="http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">" target="_blank" rel="nofollow">http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"></a>
<display-name>
ExampleWeb</display-name>
<servlet>
<servlet-name>Controller</servlet-name>
<servlet-class>com.example.Controller</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Controller</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>
 

apart from these, I'm using tomcat 5.5 and copied jstl.jar, standard.jar into WEB-INF/lib folder

and my url is http://localhost:8080/ExampleWeb/*.do

[Schandha Ravi]

It is working now.

I redesigned my application. This time as bear suggested, I just copied the jstl.jar and standard.jar into WEB-INF/lib folder and neither added any tlds nor added any taglib in my web.xml. It worked fine for me. Not sure what went wrong previously..

Thanks for all the information shared

[Bear Bibeault]

Thank goodness! I was running out of ideas!

[Schandha Ravi]

Hi Bear,

Not sure if my question is related to struts or general JSP. In this post, I understood that we neither need to copy any tlds nor editing web.xml to include taglib element is needed. However when we use struts framework, in many books I referred they copied the tlds to WEB-INF folder and also added taglib element in web.xml.

My first question is, for struts framework, do we need to copy tlds as this is separate from JSP specification.
Secondly, my web.xml is based on web-app_2_4.xsd, in which taglib element is not allowed. But all the examples I referred as based on previous versions, where in taglib is allowed. So how do I accomplish my task with web.xml based on 2.4 xsd. How do I map say

    
<%@ taglib uri="/tags/struts-logic" prefix="logic" %>

to the actual location of tld for struts-logic.

Thanks in advance.

[Bear Bibeault]

Originally posted by Schandha Ravi:
in many books I referred they copied the tlds to WEB-INF folder and also added taglib element in web.xml.

This is only necessary if the TLD does not contain a proper URI declaration.

My first question is, for struts framework, do we need to copy tlds as this is separate from JSP specification.

It has nothing to do with whether the taglibs are "official JSP" or not, but rather with how the TLD is constructed.

What you have to do for Struts is a better question for the Struts forum. I won't use it.
[ March 18, 2008: Message edited by: Bear Bibeault ]

[Schandha Ravi]

Thanks Bear.

I shall go through struts forum.