Re: Exception Listener in servicemix

[Guillaume Nodet <gn...@gmail.com>]

Maybe we should put this example on a wiki page ?

On Sat, Mar 1, 2008 at 4:55 PM, Bruce Snyder <br...@gmail.com> wrote:
>
> On Fri, Feb 29, 2008 at 3:27 PM, Tropi Geek <tr...@gmail.com> wrote:
>  > Guys, things seem to be working very well with servicemix but one of the
>  >  challenges I am facing is to track errors happening at component level.
>  >
>  >  Is there a generic listener that I can use/implement to listen to all
>  >  exceptions and then send it to a common exception queue component. I need to
>  >  report issues back to the requesting application. I can do that with most
>  >  bean/pojo components in a  try/catch block but not with any components.
>  >
>  >  Seems like a generic problem but I dont seem to be getting the right pointer
>  >  for this. Kindly help.
>
>  Well, you could create an ExchangeListener to capture every message
>  exchange flowing through the NMR. This gives you the ability to
>  manipulate the message exchanges however you like including checking
>  for errors on the exchange. Below is an example of something I wrote
>  to enhance the error messages on an exchange:
>
>  package org.apache.servicemix.jbi.exceptions;
>
>  import javax.jbi.messaging.MessageExchange;
>
>  import org.apache.servicemix.jbi.event.ExchangeEvent;
>  import org.apache.servicemix.jbi.event.ExchangeListener;
>
>  /**
>   * An {@link org.apache.servicemix.jbi.event.ExchangeListener} implementation
>   * to handle exception customization.
>   *
>   * @org.apache.xbean.XBean element="exceptionListenerService"
>   * @version $Revision$
>   * @author bsnyder
>   */
>  public class ExceptionListenerService implements ExchangeListener {
>
>     public void exchangeAccepted(ExchangeEvent event) {
>         // TODO Auto-generated method stub
>
>     }
>
>     public void exchangeSent(ExchangeEvent event) {
>         MessageExchange me = event.getExchange();
>         Exception exception = null;
>
>         if (me.getError() != null) {
>             exception = analyzeException(me);
>         }
>
>         me.setError(exception);
>     }
>
>     /**
>      * This method abstracts any special exception handling behavior.
>      *
>      * @TODO Abstract this further using pluggable strategies to hold the
>      * custom functionality. Then we just stuff the strategies that are
>      * named in the servicemix.xml config into an array and just walk the
>      * array, invoking the execute method on each strategy.
>      *
>      * @param error The exception that was thrown
>      * @param endpointName The name of the endpoint that threw the exception
>      * @return
>      */
>     private Exception analyzeException(MessageExchange me) {
>         Exception error = me.getError();
>         String serviceName = me.getEndpoint().getServiceName().toString();
>         String endpointName = me.getEndpoint().getEndpointName();
>         String errorMessage = error.getMessage();
>
>         // Add calls to custom processing here
>
>         StringBuilder newErrorMessage =
>             new StringBuilder("The following error was caused by service: [");
>         newErrorMessage.append(serviceName != null ? serviceName : "null");
>         newErrorMessage.append("] and endpoint: [");
>         newErrorMessage.append(endpointName != null ? endpointName : "null");
>         newErrorMessage.append("] ");
>         newErrorMessage.append("Original error: ");
>         newErrorMessage.append(errorMessage);
>
>         return new Exception(newErrorMessage.toString(), error);
>     }
>
>  }
>
>  To use this with ServiceMIx, you simply register it as a service in
>  the servicemix.xml file using the XBean element in the class level
>  XBean annotation (exceptionListenerService).
>
>  Bruce
>  --
>  perl -e 'print unpack("u30","D0G)U8V4\@4VYY9&5R\"F)R=6-E+G-N>61E<D\!G;6%I;\"YC;VT*"
>  );'
>
>  Apache ActiveMQ - http://activemq.org/
>  Apache Camel - http://activemq.org/camel/
>  Apache ServiceMix - http://servicemix.org/
>  Apache Geronimo - http://geronimo.apache.org/
>
>  Blog: http://bruceblog.org/
>



-- 
Cheers,
Guillaume Nodet
------------------------
Blog: http://gnodet.blogspot.com/

Re: Exception Listener in servicemix

[Bruce Snyder <br...@gmail.com>]

On Sat, Mar 1, 2008 at 12:51 PM, Guillaume Nodet <gn...@gmail.com> wrote:
> Maybe we should put this example on a wiki page ?

Yeah I was thinking that as well. Let me enhance it a bit and I'll
commit it and document it on the wiki.

Bruce
-- 
perl -e 'print unpack("u30","D0G)U8V4\@4VYY9&5R\"F)R=6-E+G-N>61E<D\!G;6%I;\"YC;VT*"
);'

Apache ActiveMQ - http://activemq.org/
Apache Camel - http://activemq.org/camel/
Apache ServiceMix - http://servicemix.org/
Apache Geronimo - http://geronimo.apache.org/

Blog: http://bruceblog.org/