Error con JSF

Antes que nada quiero mandar saludos a la comunidad Java Mexico, excelente pagina. La verdad soy nuevo en JSF leyendo unos tutoriales y ejemplos he creado mi propia pagina con JSF.

Estoy JSF1.2 Weblogic 10 R 3, como pueden ver el stacktrace me manda ese error.

La verdad no tengo idea, ese error se genera cuando genero mi reporte en pdf, en mi ManagedBean

public String aceptar() {

// logica...

response.getOutputStream().write(bytes);

return null;

}

regreso un null ya que no quiero irme a otra pagina, pero genero un pdf lo muestro en pantalla antes
response.getOutputStream().write(bytes);

Yo creo que es por eso que me manda, pero la verdad no tengo ni idea, cualquier ayuda que me puedan brindar se los agradeceria mucho

Saludos =)

<17/12/2009 12:38:38 PM CST> <[weblogic.servlet.internal.WebAppServletContext@a74ad1 - appName: 'RecepcionPagosEAR', name: 'Talonarios', context-path: '/Talonarios', spec-version: '2.5', request: weblogic.servlet.internal.ServletRequestImpl@36ca59[
POST /Talonarios/faces/pregunta.jsp HTTP/1.1
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; es-ES; rv:1.9.1.2) Gecko/20090729 Firefox/3.5.2
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: es-es,es;q=0.8,en-us;q=0.5,en;q=0.3
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: http://localhost:7001/Talonarios/faces/pregunta.jsp
Cookie: JSESSIONID=7grgLq3V4GTR6T849HJJJJGvnL5Wmtg8CnC1cLKwc151D9gclH5x!1515880587
Content-Type: application/x-www-form-urlencoded
Content-Length: 89

]] Root cause of ServletException.
java.lang.IllegalStateException: Cannot forward a response that is already committed
at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:122)
at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:408)
at com.sun.faces.application.ViewHandlerImpl.executePageToBuildView(ViewHandlerImpl.java:442)
at com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:115)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:106)
Truncated. see log file for complete stacktrace
>
17/12/2009 12:38:38 PM com.sun.faces.lifecycle.LifecycleImpl phase
ADVERTENCIA: executePhase(RENDER_RESPONSE 6,com.sun.faces.context.FacesContextImpl@27886) threw exception
java.lang.IllegalStateException: Cannot forward a response that is already committed
at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:122)
at com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:408)
at com.sun.faces.application.ViewHandlerImpl.executePageToBuildView(ViewHandlerImpl.java:442)
at com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:115)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:106)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:251)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:144)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:245)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:292)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:27)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3496)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(Unknown Source)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2180)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2086)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1406)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:173)