Need some help with servlet filters and ...

[bsmithjj.bradley.1.smith.gmail.com]

Hello,

I have a servlet filter that responds to URL patterns of *.xls.  I would like to be able to lookup a Seam component and invoke a method on it to generate the excel content that the filter streams out.  The problem I am having is that this call is returning null:

SavedQuerySearchBean savedQuerySearchBean = (SavedQuerySearchBean) Contexts.lookupInStatefulContexts("savedQuerySearchBean");

inside my filter.

I looked at the @Filter annotation in the documentation but I don't see how to have this filter respond only to *.xls URL's.

1. Why is the Contexts.lookup...() call failing?

2. What is a good way to achieve what I am trying to do (i.e. have a servlet filter that renders binary data be able to call Seam components (EJB's))?

Thanks,
Brad Smith

[srini.ragu]

Check if the SeamContextFilter also applied to that url pattern. Also try using Component.getInstance().

[pmuir]

Override getPattern() to return "*.xls"

1) no idea, what is savedQuerySearchBean? Are you wrapping the call inside a ContextualHttpServletRequest?

2) What you are doing.

[bsmithjj.bradley.1.smith.gmail.com]

Starting with 2) What are you doing. ...

We need to be able to stream out an Excel doc created using POI when the user clicks a link on a page.  The page is a JSF form and the state used to produce the Excel doc comes from the user working with the form.  The form is backed by a SFSB (SESSION scope).  The generated doc will be in Excel binary format - to my knowledge this isn't possible directly using Facelets (we're not generating textual csv data).

Override getPattern to return .xls

what does this mean?

Thanks,
Brad

[monkeyden]

Is SavedQuerySearchBean an EJB?  If so, the type needs to be the @Local interface instead.

[bsmithjj.bradley.1.smith.gmail.com]

Kyle Burke wrote on Mar 31, 2008 10:17 PM:


Is SavedQuerySearchBean an EJB?  If so, the type needs to be the @Local interface instead.

I wish I could give negative stars for replies like this ;-)

[mmichalek.mmichalek.micros-retail.com]

We need to be able to stream out an Excel doc created using POI when the user clicks a link on a page

Sounds like your filter plan will work.  Would a servlet be more appropriate for this situation? I second Pete's suggestion about checking on the ContextualHttpServletRequest in your filter as a servlet or filter needs this to tie into the Seam context somehow.

Override getPattern to return .xls

I think Pete means override the getUrlPattern method of org.jboss.seam.web.AbstractFilter and return the pattern for which you want your new filter to be invokved (*.xls). 

[bsmithjj.bradley.1.smith.gmail.com]

What is the exact set of steps I need to do to turn on a filter?

I followed section 25.1.4.8. Adding custom filters, but got the following exception:

09:06:39,663 ERROR [[/component-demo]] Exception starting filter Seam Filter
java.lang.NullPointerException
        at org.jboss.seam.servlet.SeamFilter.getSortedFilters(SeamFilter.java:131)
        at org.jboss.seam.servlet.SeamFilter.init(SeamFilter.java:93)
        at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
        at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
        at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
        at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3722)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:4367)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:790)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:770)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:553)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:296)
        at org.jboss.mx.server.RawDynamicInvoker.invoke(RawDynamicInvoker.java:164)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.apache.catalina.core.StandardContext.init(StandardContext.java:5312)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:296)
        at org.jboss.mx.server.RawDynamicInvoker.invoke(RawDynamicInvoker.java:164)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.web.tomcat.service.TomcatDeployer.performDeployInternal(TomcatDeployer.java:301)
        at org.jboss.web.tomcat.service.TomcatDeployer.performDeploy(TomcatDeployer.java:104)
        at org.jboss.web.AbstractWebDeployer.start(AbstractWebDeployer.java:375)
        at org.jboss.web.WebModule.startModule(WebModule.java:83)
        at org.jboss.web.WebModule.startService(WebModule.java:61)
        at org.jboss.system.ServiceMBeanSupport.jbossInternalStart(ServiceMBeanSupport.java:289)
        at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java:245)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:86)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.system.ServiceController$ServiceProxy.invoke(ServiceController.java:978)
        at $Proxy0.start(Unknown Source)
        at org.jboss.system.ServiceController.start(ServiceController.java:417)
        at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:86)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at $Proxy44.start(Unknown Source)
        at org.jboss.web.AbstractWebContainer.start(AbstractWebContainer.java:466)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:133)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:142)
        at org.jboss.mx.interceptor.DynamicInterceptor.invoke(DynamicInterceptor.java:97)
        at org.jboss.system.InterceptorServiceMBeanSupport.invokeNext(InterceptorServiceMBeanSupport.java:238)
        at org.jboss.wsf.container.jboss42.DeployerInterceptor.start(DeployerInterceptor.java:87)
        at org.jboss.deployment.SubDeployerInterceptorSupport$XMBeanInterceptor.start(SubDeployerInterceptorSupport.java:188)
        at org.jboss.deployment.SubDeployerInterceptor.invoke(SubDeployerInterceptor.java:95)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at $Proxy45.start(Unknown Source)
        at org.jboss.deployment.MainDeployer.start(MainDeployer.java:1025)
        at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:819)
        at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:782)
        at sun.reflect.GeneratedMethodAccessor20.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:133)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:142)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at $Proxy9.deploy(Unknown Source)
        at org.jboss.deployment.scanner.URLDeploymentScanner.deploy(URLDeploymentScanner.java:421)
        at org.jboss.deployment.scanner.URLDeploymentScanner.scan(URLDeploymentScanner.java:610)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.doScan(AbstractDeploymentScanner.java:263)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.loop(AbstractDeploymentScanner.java:274)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.run(AbstractDeploymentScanner.java:225)

[bsmithjj.bradley.1.smith.gmail.com]

I got it - thanks for the help Pete and Mark.

The filter has this structure:

@Name("StreamExcelFilter")
@Scope(ScopeType.APPLICATION)
@Filter(within="org.jboss.seam.web.ajax4jsfFilter")
public class StreamExcelFilter extends AbstractFilter {

    @In(required = false)
    private List<EvergreenUser> targetEmployees;

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse,
                         FilterChain filterChain)
        throws IOException, ServletException {

        servletResponse.setContentType("application/vnd.ms-excel");


        // generate some excel content

    }

    public String getUrlPattern() {
        return "*.xls";
    }
}

and EVERY annotation shown in the sample code MUST be used for it to work. 

Thanks,
Brad Smith

PS - the seam text drives me krazeee!

[monkeyden]

Bradley Smith wrote on Apr 01, 2008 01:44 AM:


I wish I could give negative stars for replies like this ;-)

Believe it or not, this was recently at the root of an associate's problems.  Of course not knowing you, let alone your apparently impressive credentials, it was worth asking.

[bsmithjj.bradley.1.smith.gmail.com]

Kyle Burke wrote on Apr 01, 2008 05:32 PM:


Believe it or not, this was recently at the root of an associate's problems.  Of course not knowing you, let alone your apparently impressive credentials, it was worth asking.

I have had many obvious blunders (with Seam, JSF, etc... pick one) before but I didn't think anything in my post suggested an issue with EJB's and EJB-annotation usage.  Anyway, as you can see, I've got the filter working.  I kinda like it better than the ole-fashioned filter-in-web.xml approach.