Servlets - error en ServletOutputStream

Hola, estoy intentando generar un pdf, al ejecutar, da un error en tiempo de ejecucion :

java.lang.IllegalStateException: Response has already been committed<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].server.http.EvermindHttpServletResponse.resetBuffer(EvermindHttpServletResponse.java:1904)<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].server.http.ServletRequestDispatcher.forward(ServletRequestDispatcher.java:211)<br> at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)<br> at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)<br> at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)<br> at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)<br> at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)<br> at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)<br> at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:823)<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:322)<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)<br> at com.evermind[Oracle Application Server Containers for J2EE 10g (10.1.2.0.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)<br> at java.lang.Thread.run(Thread.java:534

El codigo es este:
byte[] pdf = OperacionesAuxiliares.ejecutaPDF(ficheroReport,mapParametros,true);
ServletOutputStream outputStream = response.getOutputStream();
response.setContentType(\"application/pdf\");
response.setContentLength(pdf.length);
response.addHeader(\"Content-Disposition\",\"attachment;\");
response.setBufferSize(1024 * 15);
outputStream.write(pdf);
outputStream.flush();
outputStream.close();
return (mapping.findForward(\"success\"));

Haber si alguien sabe algo de este error.

hola esta mostrandose un error por invocacion de los metodos

outputStream.close();
// estas diciendo a tu servlet que muestre el contenido segun las configuraciones
//dirijas la salida

return (mapping.findForward(\"success\"));
// aqui nuevamente estas redirijiendo el servlet cosa q no se puede hacer por que ya tienes un destino