[jsf 2 , iText ] problem to generate pdf file

[ensemien]

Hello everyone 

i am working my Graduation Project with jee technology (JSF 2 ,Spring,richfaces4) and i have to generate report (pdf file) ,

i tried some solution like ireport but i am not satidfied ; i want to try iText with jsf ; i am reading this tutorial : http://docs.jboss.com/seam/1.1.6.GA/reference/en/html/itext.html

but i have error to generate the pdf ;

this is my facelet (testRich2.xhtml) :

<p:document xmlns:p="http://jboss.com/products/seam/pdf"> 

    <p:font size="24">
        <p:paragraph spacingAfter="50">My First Document</p:paragraph>
    </p:font>

    <p:paragraph alignment="justify">
        This is a simple document.  It isn't very fancy.
    </p:paragraph>
</p:document>

and this is the error :

Grave: "Servlet.service()" pour la servlet Faces Servlet a généré une exception
java.lang.IllegalArgumentException: null source
    at java.util.EventObject.<init>(Unknown Source)
    at javax.faces.event.SystemEvent.<init>(SystemEvent.java:71)
    at javax.faces.event.ComponentSystemEvent.<init>(ComponentSystemEvent.java:73)
    at javax.faces.event.PostRestoreStateEvent.<init>(PostRestoreStateEvent.java:73)
    at com.sun.faces.lifecycle.RestoreViewPhase.deliverPostRestoreStateEvent(RestoreViewPhase.java:271)
    at com.sun.faces.lifecycle.RestoreViewPhase.execute(RestoreViewPhase.java:257)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.RestoreViewPhase.doPhase(RestoreViewPhase.java:116)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Unknown Source)

in my  lib directory : there are : iText 2.1.7 .jar  ,     jboos-seam-pdf.2.1.2 .jar  and . jboos.seam.jar

i need your help please .