Witam...
robiłem przykład ze strony : http://frogermcs.blogspot.com/2011/03/wstep-do-managed-bean-w-jsf20.html
Wszystko wykonywałem krok po kroku i w rezultacie gdy wpiszę w przeglądarce http://localhost:8080/HelloJSF/
wywala mi :

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: javax/servlet/jsp/jstl/core/Config
javax.faces.webapp.FacesServlet.service(FacesServlet.java:325)

root cause

java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/Config
com.sun.faces.application.view.JspViewHandlingStrategy.executePageToBuildView(JspViewHandlingStrategy.java:344)
com.sun.faces.application.view.JspViewHandlingStrategy.buildView(JspViewHandlingStrategy.java:154)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:100)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:313)

root cause

java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.Config
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
com.sun.faces.application.view.JspViewHandlingStrategy.executePageToBuildView(JspViewHandlingStrategy.java:344)
com.sun.faces.application.view.JspViewHandlingStrategy.buildView(JspViewHandlingStrategy.java:154)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:100)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:313)

i z eclipse'a :

2011-07-01 1752 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Faces Servlet] in context with path [/HelloJSF] threw exception [javax/servlet/jsp/jstl/core/Config] with root cause
java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/Config
at com.sun.faces.application.view.JspViewHandlingStrategy.executePageToBuildView(JspViewHandlingStrategy.java:344)
at com.sun.faces.application.view.JspViewHandlingStrategy.buildView(JspViewHandlingStrategy.java:154)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:100)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:313)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:403)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:301)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:162)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:140)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Może ktoś wie ocb?
do pliku faces-config.xml nie dodałem beana klasy ponieważ w klasie wstawiłem @ManagedBean i @SessionScoped(JSF2.0).
Zresztą i tak jak dodam to jest to samo....

Pozdrawiam...