Dificuldade com DataExporter'

implementei certinho como ta no exemplo do primefaces mas me da um erro cabuloso o exemplo é esse http://www.primefaces.org/showcase-labs/ui/exporterProcessor.jsf

meu metodo

[code]public void preProcessPDF(Object document) throws IOException, BadElementException, DocumentException {
Document pdf = (Document) document;
pdf.open();
pdf.setPageSize(PageSize.A4);

    ServletContext servletContext = (ServletContext) FacesContext.getCurrentInstance().getExternalContext().getContext();  
    String logo = servletContext.getRealPath("") + File.separator + "images" + File.separator + "prime_logo.png";  
  
    pdf.add(Image.getInstance(logo));  
}  
[/code]

o erro

11/01/2012 17:23:48 com.sun.faces.lifecycle.InvokeApplicationPhase execute AVISO: /paginas/teste.xhtml @52,57 preProcessor="#{funcionarioBean.preProcessPDF}": java.lang.ClassCastException: com.lowagie.text.Document cannot be cast to com.itextpdf.text.Document javax.el.ELException: /paginas/teste.xhtml @52,57 preProcessor="#{funcionarioBean.preProcessPDF}": java.lang.ClassCastException: com.lowagie.text.Document cannot be cast to com.itextpdf.text.Document at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:104) at org.primefaces.component.export.PDFExporter.export(PDFExporter.java:50) at org.primefaces.component.export.DataExporter.processAction(DataExporter.java:94) at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88) at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:772) at javax.faces.component.UICommand.broadcast(UICommand.java:300) at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:775) at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1267) at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:312) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:343) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:177) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:149) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:403) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:301) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:162) at org.apache.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) Caused by: java.lang.ClassCastException: com.lowagie.text.Document cannot be cast to com.itextpdf.text.Document at br.com.projeto.controller.FuncionarioBean.preProcessPDF(FuncionarioBean.java:159) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.el.parser.AstValue.invoke(AstValue.java:262) at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278) at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:98) ... 57 more 11/01/2012 17:23:48 org.apache.catalina.core.StandardWrapperValve invoke GRAVE: Servlet.service() for servlet [Faces Servlet] in context with path [/Projeto_Faculdade] threw exception [com.lowagie.text.Document cannot be cast to com.itextpdf.text.Document] with root cause java.lang.ClassCastException: com.lowagie.text.Document cannot be cast to com.itextpdf.text.Document at br.com.projeto.controller.FuncionarioBean.preProcessPDF(FuncionarioBean.java:159) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.apache.el.parser.AstValue.invoke(AstValue.java:262) at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278) at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:98) at org.primefaces.component.export.PDFExporter.export(PDFExporter.java:50) at org.primefaces.component.export.DataExporter.processAction(DataExporter.java:94) at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88) at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:772) at javax.faces.component.UICommand.broadcast(UICommand.java:300) at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:775) at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1267) at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:312) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:79) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:343) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:177) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:149) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) 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$Http11ConnectionHandler.process(Http11Protocol.java:162) at org.apache.tomcat.util.net.JIoEndpoint$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)

meus imports

[code]import com.itextpdf.text.BadElementException;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
[/code]

coloquei os jars do itext e do POI