Using Facelets as <error-page><location> causes IllegalStateException: getWriter() has already been called for this response

Question

I'm trying to setup the Omniface's FaceExceptionFilter on my Glassfish 4.0 server, using Mojarra 2.2.8, Primefaces 4.0 and Omnifaces 1.8.1.

The filters and error pages in web.xml are defined as follow:

<filter>
    <filter-name>facesExceptionFilter</filter-name>
    <filter-class>org.omnifaces.filter.FacesExceptionFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>facesExceptionFilter</filter-name>
    <servlet-name>Faces Servlet</servlet-name>
</filter-mapping>
<filter>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <filter-class>org.primefaces.webapp.filter.FileUploadFilter         </filter-class>
</filter>
<filter-mapping>
    <filter-name>PrimeFaces FileUpload Filter</filter-name>
    <servlet-name>Faces Servlet</servlet-name>
</filter-mapping>
<error-page>
    <error-code>500</error-code>
    <location>/errors/500.xhtml</location>
</error-page>
<error-page>
    <error-code>404</error-code>
    <location>/errors/404.xhtml</location>
</error-page>
<error-page>
    <exception-type>javax.faces.application.ViewExpiredException</exception-type>
    <location>/errors/expired.xhtml</location>
</error-page>
<error-page>
    <exception-type>java.lang.Throwable</exception-type>
    <location>/errors/throwable.xhtml</location>
</error-page>

I try to trigger the 404 exception by going to an non-existing page. This result in the following exception:

Severe:   PWC6117: File "/home/cghislai/Misc/dev/kountos/repo/kountos/jkountos-web/target/tagific-1.0-SNAPSHOT/feesd.jsp" not found
Warning:   Servlet.service() for servlet default threw exception
java.lang.IllegalStateException: getWriter() has already been called for this response
    at org.apache.catalina.connector.Response.getOutputStream(Response.java:746)
    at org.apache.catalina.connector.ResponseFacade.getOutputStream(ResponseFacade.java:206)
    at javax.servlet.ServletResponseWrapper.getOutputStream(ServletResponseWrapper.java:142)
    at org.apache.catalina.servlets.DefaultServlet.serveResource(DefaultServlet.java:1033)
    at org.apache.catalina.servlets.DefaultServlet.doGet(DefaultServlet.java:518)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:875)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:739)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:695)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:626)
    at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:492)
    at org.apache.catalina.core.StandardHostValve.dispatchToErrorPage(StandardHostValve.java:691)
    at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:376)
    at org.apache.catalina.core.StandardHostValve.postInvoke(StandardHostValve.java:234)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:359)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
    at java.lang.Thread.run(Thread.java:745)

Warning:   org.apache.catalina.core.StandardHostValve@a5ebfc0: Exception Processing ErrorPage[errorCode=404, location=/errors/404.xhtml]
java.lang.IllegalStateException: getWriter() has already been called for this response
    at org.apache.catalina.connector.Response.getOutputStream(Response.java:746)
    at org.apache.catalina.connector.ResponseFacade.getOutputStream(ResponseFacade.java:206)
    at javax.servlet.ServletResponseWrapper.getOutputStream(ServletResponseWrapper.java:142)
    at org.apache.catalina.servlets.DefaultServlet.serveResource(DefaultServlet.java:1033)
    at org.apache.catalina.servlets.DefaultServlet.doGet(DefaultServlet.java:518)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:875)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:739)
    at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:695)
    at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:626)
    at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:492)
    at org.apache.catalina.core.StandardHostValve.dispatchToErrorPage(StandardHostValve.java:691)
    at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:376)
    at org.apache.catalina.core.StandardHostValve.postInvoke(StandardHostValve.java:234)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:359)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
    at java.lang.Thread.run(Thread.java:745)

I've checked any filter that could write to the response before the FacesExceptionFilter, and ended up disabling all my @WebFilters, but the error remains.

Thanks for any tip!

Answer 1

If you're setting a JSF/Facelets page as <error-page><location>, then you need to make sure that the URL in <location> matches the <url-pattern> of the FacesServlet. The stack trace indicates that the DefaultServlet is being invoked instead of FacesServlet, which means that the URL in <location> indeed doesn't match the <url-pattern> of FacesServlet.

It's recommended to map the FacesServlet directly on *.xhtml instead of e.g. *.jsf or /faces/*, so that you never need to fiddle with virtual URLs.

<servlet-mapping>
    <servlet-name>Faces Servlet</servlet-name>
    <url-pattern>*.xhtml</url-pattern>
</servlet-mapping>

See also:

• JSF Facelets: Sometimes I see the URL is .jsf and sometimes .xhtml. Why?