Ireport + JSF

Tenho um metódo:

public static void executeReport() throws IOException, ParseException,SQLException {

Connection con = JdbcDAO.getConexao();

FacesContext context = FacesContext.getCurrentInstance();

HttpServletResponse response = (HttpServletResponse) context.getExternalContext().getResponse();

ServletContext scontext = (ServletContext) context.getExternalContext().getContext();

ServletOutputStream servletOutputStream = response.getOutputStream();

File reportFile = new File(scontext.getRealPath("/WEB-INF/reports/JDBCHoldingReport.jasper"));

byte[] bytes = null;

try {

bytes = JasperRunManager.runReportToPdf(reportFile.getPath(), null, con);

response.setContentType(“application/pdf”);

response.setContentLength(bytes.length);

servletOutputStream.write(bytes, 0, bytes.length);
        servletOutputStream.flush();
        servletOutputStream.close();
    } catch (JRException e) {
        StringWriter stringWriter = new StringWriter();
        PrintWriter printWriter = new PrintWriter(stringWriter);
        e.printStackTrace(printWriter);
        response.setContentType("text/plain");
        response.getOutputStream().print(stringWriter.toString());
    }
}

java.lang.IllegalStateException: Servlet response already use stream, Writer not possible

at org.ajax4jsf.webapp.FilterServletResponseWrapper.getWriter(FilterServletResponseWrapper.java:226)

at com.sun.facelets.FaceletViewHandler.createResponseWriter(FaceletViewHandler.java:414)

at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:571)

at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108)

at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:216)

at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:41)

at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:140)

at javax.faces.webapp.FacesServlet.service(FacesServlet.java:152)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141)

at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:111)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

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:175)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)

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:263)

at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)

at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)

at java.lang.Thread.run(Thread.java:619)