java.lang.IllegalStateException
at com.liferay.portal.servlet.filters.gzip.GZipResponse.getWriter(GZipResponse.java:113)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at com.liferay.portlet.MimeResponseImpl.getWriter(MimeResponseImpl.java:96)
at com.liferay.faces.bridge.context.BridgeContextImpl.getResponseOutputWriter(BridgeContextImpl.java:1212)
at com.liferay.faces.bridge.context.ExternalContextImpl.getResponseOutputWriter(ExternalContextImpl.java:1103)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.createResponseWriter(FaceletViewHandlingStrategy.java:934)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:376)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:288)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at com.liferay.faces.bridge.lifecycle.LifecycleWrapper.render(LifecycleWrapper.java:45)
at com.liferay.faces.bridge.BridgePhaseResourceImpl.execute(BridgePhaseResourceImpl.java:115)
at com.liferay.faces.bridge.BridgeImpl.doFacesRequest(BridgeImpl.java:115)
at javax.portlet.faces.GenericFacesPortlet.serveResource(GenericFacesPortlet.java:178)
at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:119)
at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:71)
at com.liferay.portal.kernel.servlet.PortletServlet.service(PortletServlet.java:92)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at com.liferay.portlet.InvokerPortletImpl.invoke(InvokerPortletImpl.java:635)
at com.liferay.portlet.InvokerPortletImpl.invokeResource(InvokerPortletImpl.java:747)
at com.liferay.portlet.InvokerPortletImpl.serveResource(InvokerPortletImpl.java:504)
at com.liferay.portal.action.LayoutAction.processPortletRequest(LayoutAction.java:871)
at com.liferay.portal.action.LayoutAction.processLayout(LayoutAction.java:613)
at com.liferay.portal.action.LayoutAction.execute(LayoutAction.java:232)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at com.liferay.portal.struts.PortalRequestProcessor.process(PortalRequestProcessor.java:153)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at com.liferay.portal.servlet.MainServlet.callParentService(MainServlet.java:508)
at com.liferay.portal.servlet.MainServlet.service(MainServlet.java:485)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.strip.StripFilter.processFilter(StripFilter.java:309)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.gzip.GZipFilter.processFilter(GZipFilter.java:121)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.secure.SecureFilter.processFilter(SecureFilter.java:182)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.autologin.AutoLoginFilter.processFilter(AutoLoginFilter.java:254)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at com.liferay.portal.servlet.FriendlyURLServlet.service(FriendlyURLServlet.java:134)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.strip.StripFilter.processFilter(StripFilter.java:309)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.gzip.GZipFilter.processFilter(GZipFilter.java:110)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.secure.SecureFilter.processFilter(SecureFilter.java:182)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.i18n.I18nFilter.processFilter(I18nFilter.java:222)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.cache.CacheFilter.processFilter(CacheFilter.java:442)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.etag.ETagFilter.processFilter(ETagFilter.java:45)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.autologin.AutoLoginFilter.processFilter(AutoLoginFilter.java:254)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.sso.ntlm.NtlmPostFilter.processFilter(NtlmPostFilter.java:81)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.sharepoint.SharepointFilter.processFilter(SharepointFilter.java:179)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.virtualhost.VirtualHostFilter.processFilter(VirtualHostFilter.java:240)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:126)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:738)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:196)
at com.liferay.portal.servlet.filters.threadlocal.ThreadLocalFilter.processFilter(ThreadLocalFilter.java:35)
at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:123)
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:191)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:470)
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:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
11:57:34,618 INFO [PortalImpl:3829] Current URL /web/guest/home?p_p_id=ClosedCases_WAR_WBPortlets&p_p_lifecycle=2&p_p_state=normal&p_p_mode=view&p_p_cacheability=cacheLevelPage&p_p_col_id=column-1&p_p_col_count=2&_ClosedCases_WAR_WBPortlets__jsfBridgeAjax=true&_ClosedCases_WAR_WBPortlets__facesViewIdResource=%2Fxhtml%2Fclosedcases%2FapplicationView.xhtml generates exception: java.lang.IllegalStateException


My Code:
xhtml:
<ice:commandButton ajax="false" action="#{closedCasesManagementController.CSVfile()}" value="Export" update="revgrid" immediate="true" />

managed Bean:

public void CSVfile()
{
System.out.println("Begin ------ ");
try
{
FacesContext ctx = FacesContext.getCurrentInstance();
ExternalContext ectx = ctx.getExternalContext();
HttpServletRequest request = (HttpServletRequest) ectx.getRequest();
HttpServletResponse response = (HttpServletResponse) ectx.getResponse();
RequestDispatcher dispatcher = request.getRequestDispatcher("/process");
dispatcher.forward(request, response);
ctx.responseComplete();
}
catch(Exception e){
e.printStackTrace();
}
/*FacesContext context = FacesContext.getCurrentInstance();
ExternalContext externalContext = context.getExternalContext();
externalContext.responseReset();
externalContext.setResponseContentType("text/csv");

// externalContext.setResponseContentType("application/vnd.ms-excel");
externalContext.setResponseHeader("Content-Disposition", "attachment;filename=export.xls");
// workbook.write(externalContext.getResponseOutputStream());
context.responseComplete(); // Prevent JSF from performing navigation.
*/
System.out.println("------ End");
}

Servlet:

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment; filename=\"my.xls\"");
System.out.println("he-------------------");
HSSFWorkbook workbook = new HSSFWorkbook();

HSSFSheet sheet = workbook.createSheet();
HSSFRow row = sheet.createRow(0);
HSSFCell cell = row.createCell(0);
cell.setCellValue(0.0);

FileOutputStream out = new FileOutputStream("my.xls");
workbook.write(out);
out.close();
}

web.xml


<servlet>
<servlet-name>ExportExcel</servlet-name>
<servlet-class>icici.wb.ExportExcel</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ExportExcel</servlet-name>
<url-pattern>/process</url-pattern>
</servlet-mapping>

This is your problem. In a portal environment, the response stream is already partially written to by the time your portlet gets control. You are trying to take control back from the portal in order to output your own stream which contains the CSV file data.

Now, if you were using JSP for example, I'd tell you to turn this into a resource request (those have total access to the output stream and the portal will not have written any data in there before your code gets invoked).

The response to you is basically the same, but the caveat is that I don't know how to tell you to do that within IceFaces...

First, I would recommend that you upgrade to JSF 2 + ICEfaces 3.2.

Second, I would recommend that you look at the source code for the jsf2-export-pdf-portlet demo. It shows how to use a JSF 2 ResourceHandler in order to generate a PDF dynamically. You could modify this to generate a spreadsheet.