[ 
https://issues.jboss.org/browse/RF-13674?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Brian Leathem updated RF-13674:
-------------------------------

    Fix Version/s:     (was: 4.5.0.Beta1)


> a4j:push broken on WebLogic 12c in Chrome
> -----------------------------------------
>
>                 Key: RF-13674
>                 URL: https://issues.jboss.org/browse/RF-13674
>             Project: RichFaces
>          Issue Type: Bug
>      Security Level: Public(Everyone can see) 
>          Components: component-push/poll
>    Affects Versions: 4.2.0.Final
>         Environment: WebLogic 12c
>            Reporter: Val Blant
>         Attachments: atmosphere-weblogic12c-bug-0.8.4-sources.jar, 
> atmosphere-weblogic12c-bug-0.8.4.war, RichFacesPushFixFilter.java
>
>
> <a4j:push />  works properly on Tomcat 7, but fails on WebLogic 12c in Chrome 
> (Firefox works fine).
> {code:title=Page.xhtml|borderStyle=solid}
> <a4j:push address="systemLinks" >  
>   <a4j:ajax event="dataavailable" render="systemLinksPanel" />  
> </a4j:push>  
>   
> <a4j:outputPanel id="systemLinksPanel">  
>      stuff here  
> </a4j:outputPanel>  
> {code}
> {code:title=Java Code}
> TopicKey topicKey = new TopicKey("systemLinks");  
> TopicsContext topicsContext = TopicsContext.lookup();  
> topicsContext.publish(topicKey, "fly, you fools!");  
> {code}
> On Tomcat 7 this work perfectly, and always refreshes '_systemLinksPanel_' 
> when data is published. 
> On Weblogic 12c the data is not flushed correctly. If you use Wireshark, 
> you'd see the following response coming back from the server:
> {panel:title=Tomcat 7}
> 3b
> <"topic":"systemLinks","data":"fly, you fools!","number":0>
> 0
> {panel}
> {panel:title=Weblogic 12c}
> 003b
> <"topic":"systemLinks","data":"fly, you fools!","number":0>
> {panel}
> *Note the missing zero terminator line in the WebLogic response!*
> I narrowed down the problem to the following:
> {code:title=org.richfaces.application.push.impl.RequestImpl}
>     public synchronized void 
> onBroadcast(AtmosphereResourceEvent<HttpServletRequest, HttpServletResponse> 
> event) {
>         MessageDataScriptString serializedMessages = 
> (MessageDataScriptString) event.getMessage();
>         
> getSession().clearBroadcastedMessages(serializedMessages.getLastSequenceNumber());
>         hasActiveBroadcaster = false;
>         if (isPolling()) {
>             event.getResource().resume(); // <= THIS LINE
>         } else {
>             postMessages();
>         }
>     }
> {code}
> There is nothing wrong with this in principle, but it does not work due to a 
> bug in Atmosphere 0.8.4. Calling _AtmosphereResource.resume()_ at this point 
> seems reasonable, since it is supposed to properly finish/commit the 
> _HttpServletResponse_.  However, this does not work on WebLogic 12c and leads 
> to incorrectly flushed data demonstrated above. 
> The underlying problem seems to be the fact that 
> _AtmosphereResource.resume()_ method interrupts the thread which flushed the 
> socket Writer before a call to _asyncContext.complete()_ is made:
> {code}
> public AtmosphereResource resume() {
> ....
>  if (!b.isDestroyed()) {
>      b.removeAtmosphereResource(event.getResource());
>  }
> ....
>  asyncSupport.action(this); // <= This is where asyncContext.complete() is 
> called
> }
> {code}
> I have verified that calling _asyncContext.complete()_ before we clean up 
> Atmosphere resources fixes the problem.
> Here's the fix, which needs to go into _RequestImpl.onBroadcast_:
> {code:title=org.richfaces.application.push.impl.RequestImpl}
>     public synchronized void 
> onBroadcast(AtmosphereResourceEvent<HttpServletRequest, HttpServletResponse> 
> event) {
>   ..............
>         if (isPolling()) {
> // This is the workaround. Completing AsyncContext before cleaning up 
> Atmosphere resources
> // seems to make this work everywhere.
> //
> AsyncContext asyncContext = (AsyncContext) 
>       event
>               .getResource()
>               .getRequest()
>               .getAttribute("org.atmosphere.container.asyncContext");
>    if ( asyncContext != null ) {
>       asyncContext.complete();
>    }
>             event.getResource().resume();
>         } else {
>             postMessages();
>         }
>     }
>   ..............
> {code}
> I am attaching a very simple WAR file that demonstrates the problem clearly. 
> The demo app does not use Richfaces, b/c I wanted to remove all unnecessary 
> complexity. Instead I created a couple of simple classes that mimic the 
> behavior of _org.richfaces.webapp.PushHandlerFilter_ and 
> _org.richfaces.application.push.impl.RequestImpl_. In the demo app, 
> _MeteorRequest = RequestImpl_, which is where the fix needs to go.
> Please note that this issue is fixed in Atmosphere 2.1. I ran the demo jar 
> with v2.1.5, and it works correctly, so the easiest fix on the RichFaces side 
> could be to simply upgrade the underlying Atmosphere framework. The API 
> differences, at least as far as the PushHandlerFilter is concerned are 
> minimal.
> Now, the reason why only Chrome is effected has to do with processing of 
> chunked responses by the XMLHttpRequest. Unlike other browsers, Chrome is not 
> capable of handling improperly terminated chunked responses. So:
> {noformat}
> HTTP/1.1 200 OK
> Cache-Control: no-store, no-cache, must-revalidate
> Date: Wed, 18 Jun 2014 05:37:55 GMT
> Pragma: no-cache
> Transfer-Encoding: chunked <<--- THIS IS IMPORTANT
> Content-Type: text/plain
> Expires: -1
> Access-Control-Allow-Credentials: true
> Access-Control-Allow-Origin: *
> X-Powered-By: Servlet/3.0 JSP/2.2
> 0841
> <!-- ---------------------------------------------------------------- 
> http://github.com/Atmosphere 
> ------------------------------------------------------------------------ -->
> <!-- Welcome to the Atmosphere Framework. To work with all the browsers when 
> suspending connection, Atmosphere must output some data to makes WebKit based 
> browser working.-->
> <!-- 
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>  -->
> <!-- 
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>  -->
> <!-- 
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>  -->
> <!-- 
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>  -->
> <!-- 
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>  -->
> <!-- 
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
>  -->
> <!-- --------------------001c
> Wed Jun 18 13:37:57 CST 201
> <<--- MISSING 0 TERMINATOR
> {noformat}
> This can be fixed by explicitly setting Content-Length in the response, as 
> per these discussions:
> http://stackoverflow.com/questions/22219565/iis-chrome-failed-to-load-resource-neterr-incomplete-chunked-encoding
> http://www.rahulsingla.com/blog/2010/06/asp-net-sets-the-transfer-encoding-as-chunked-on-premature-flushing-the-response
> However, that does not seem to be feasible here, since we must reply with a 
> header of known length, followed by the data of unknown length.



--
This message was sent by Atlassian JIRA
(v6.2.6#6264)
_______________________________________________
richfaces-issues mailing list
richfaces-issues@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/richfaces-issues

Reply via email to