Hello, I'm not sure I understand why I shouldn't be using getOut(). Here is what I do at the end of my processor (that is transforming the message Body):
// propagate headers ex.getOut().setHeaders(ex.getIn().getHeaders()); Am I wrong? I saw a couple of Processor samples that were only dealing with getIn() but I don't quite understand how and when the "in" message becomes an "out" message and I noticed that if I was propagating my headers by copying them from the "in" message to the "out" one I was no longer losing them. I'm looking forward to the latest MEAP version of Camel In Action since it seems I got it wrong somewhere. > -----Message d'origine----- > De : bengt.rode...@gmail.com [mailto:bengt.rode...@gmail.com] De la > part de Bengt Rodehav > Envoyé : vendredi 24 septembre 2010 12:47 > À : users@camel.apache.org > Objet : Re: Camel Exchange Patters > > Perfect! > > /Bengt > > 2010/9/24 Claus Ibsen <claus.ib...@gmail.com> > > > On Fri, Sep 24, 2010 at 10:27 AM, Claus Ibsen <claus.ib...@gmail.com> > > wrote: > > > On Tue, Sep 14, 2010 at 2:29 PM, Bengt Rodehav <be...@rodehav.com> > > wrote: > > >> Yeah I remember reading about the problems with losing message > headers > > >> somewhere on this list... > > >> > > >> To be perfectly honest I think that the number of mails on this > thread > > >> indicates the importance of documenting these rules and how things > work. > > >> Claus, you are most definitely the man to do it. I've got your > book > > (haven't > > >> read the last updates though) and it certainly warrants a place > there. > > >> Perhaps it should also be on the wiki somewhere. > > >> > > > > > > We have added information about this in Camel in action, > > > chapter 3 when we drill down and work the Processor which exposes > the > > > Exchange API. > > > > > > > I also added a couple of FAQs as well, such as > > > > > https://cwiki.apache.org/confluence/display/CAMEL/Using+getIn+or+getOut > +methods+on+Exchange > > > > > > > >> /Bengt > > >> > > >> 2010/9/14 Claus Ibsen <claus.ib...@gmail.com> > > >> > > >>> On Tue, Sep 14, 2010 at 2:16 PM, Bengt Rodehav <be...@rodehav.com> > > wrote: > > >>> > I think that was very useful information. I hadn't thought of a > > Processor > > >>> as > > >>> > very low level - it's definitely a level that a lot of us will > use. > > Then > > >>> I > > >>> > guess that in some circumstances (like when coding a custom > > processor) > > >>> you > > >>> > need to set the out messsage if the MEP is "out capable" > otherwise > > you > > >>> just > > >>> > set the in message. Are there more situations where this is > needed? > > >>> > > > >>> > > >>> If the MEP is out capable you can still just change the IN > message. > > >>> If the OUT is null, then Camel will re-use the IN (which you just > > >>> changed) and thus still route whatever you have changed. > > >>> > > >>> You only need to use OUT if you want to create a totally 100% new > > >>> message which is not related to the IN message at all. > > >>> And this is only needed in special cases. > > >>> > > >>> Otherwise you get the problem with: Why do I lose my message > headers > > etc. > > >>> > > >>> > > >>> > > >>> > I think that this subject is definitely complicated enough to > warrant > > a > > >>> good > > >>> > documentation somewhere. I think it's really important for > developers > > to > > >>> > understand core concepts instead of just using boilerplate > samples > > >>> (although > > >>> > they are very useful). > > >>> > > > >>> > /Bengt > > >>> > > > >>> > 2010/9/14 Claus Ibsen <claus.ib...@gmail.com> > > >>> > > > >>> >> On Tue, Sep 14, 2010 at 10:23 AM, Christian Müller > > >>> >> <christian.muel...@gmail.com> wrote: > > >>> >> > Hello Claus! > > >>> >> > > > >>> >> > That's not (in my opinion) how it works currently. At > present I > > work > > >>> on a > > >>> >> > route which looks like this: > > >>> >> > > > >>> >> > errorHandler( > > >>> >> > defaultErrorHandler() > > >>> >> > .retryAttemptedLogLevel(LoggingLevel.DEBUG) > > >>> >> > .retriesExhaustedLogLevel(LoggingLevel.INFO)); > > >>> >> > > > >>> >> > onException(IllegalArgumentException.class) > > >>> >> > .handled(true) > > >>> >> > .maximumRedeliveries(0) > > >>> >> > .beanRef("myResultProvider", "failureResponse"); > > >>> >> > > > >>> >> > from("cxf:bean:MyCoolService") > > >>> >> > .processRef("myValidator") // validates conditional rules > > >>> >> > .inOut("direct:mySubroute") > > >>> >> > .beanRef("myResultProvider", "successResponse") > > >>> >> > > > >>> >> > > > >>> >> > If my validator throws a IllegalArgumentException and the > result > > >>> provider > > >>> >> > writes the response into the in message, the web service > will > > return > > >>> >> null. > > >>> >> > But if I write the response into the out message, the web > service > > will > > >>> >> > return it. So, I changes my bean to the following "pattern": > > >>> >> > > > >>> >> > > >>> >> Well that could CXF Bean component having a bug. > > >>> >> > > >>> >> If you decide to use a Processor and work on Exchange then you > use > > the > > >>> >> low level Camel API and then you have to handle the IN/OUT > stuff > > >>> >> yourself. > > >>> >> > > >>> >> > > >>> >> > > >>> >> > > >>> >> > if (exchange.getPattern().isOutCapable()) { > > >>> >> > exchange.getOut().setBody(response); > > >>> >> > } else { > > >>> >> > exchange.getIn().setBody(response); > > >>> >> > } > > >>> >> > > > >>> >> > And that's the same how the > > >>> >> org.apache.camel.processor.ConvertBodyProcessor > > >>> >> > works (I know you know this, but for the other guys.. :o) ) > > >>> >> > > > >>> >> > public class ConvertBodyProcessor implements Processor { > > >>> >> > ... > > >>> >> > public void process(Exchange exchange) throws Exception { > > >>> >> > Message in = exchange.getIn(); > > >>> >> > if (charset != null) { > > >>> >> > exchange.setProperty(Exchange.CHARSET_NAME, > charset); > > >>> >> > } > > >>> >> > Object value = in.getMandatoryBody(type); > > >>> >> > > > >>> >> > if (exchange.getPattern().isOutCapable()) { > > >>> >> > Message out = exchange.getOut(); > > >>> >> > out.copyFrom(in); > > >>> >> > out.setBody(value); > > >>> >> > } else { > > >>> >> > in.setBody(value); > > >>> >> > } > > >>> >> > } > > >>> >> > ... > > >>> >> > } > > >>> >> > > > >>> >> > Should our custom processors/beans/.. not work in the same > way? > > >>> >> > > > >>> >> > Cheers, > > >>> >> > Christian > > >>> >> > > > >>> >> > > >>> >> > > >>> >> > > >>> >> -- > > >>> >> Claus Ibsen > > >>> >> Apache Camel Committer > > >>> >> > > >>> >> Author of Camel in Action: http://www.manning.com/ibsen/ > > >>> >> Open Source Integration: http://fusesource.com > > >>> >> Blog: http://davsclaus.blogspot.com/ > > >>> >> Twitter: http://twitter.com/davsclaus > > >>> >> > > >>> > > > >>> > > >>> > > >>> > > >>> -- > > >>> Claus Ibsen > > >>> Apache Camel Committer > > >>> > > >>> Author of Camel in Action: http://www.manning.com/ibsen/ > > >>> Open Source Integration: http://fusesource.com > > >>> Blog: http://davsclaus.blogspot.com/ > > >>> Twitter: http://twitter.com/davsclaus > > >>> > > >> > > > > > > > > > > > > -- > > > Claus Ibsen > > > Apache Camel Committer > > > > > > Author of Camel in Action: http://www.manning.com/ibsen/ > > > Open Source Integration: http://fusesource.com > > > Blog: http://davsclaus.blogspot.com/ > > > Twitter: http://twitter.com/davsclaus > > > > > > > > > > > -- > > Claus Ibsen > > Apache Camel Committer > > > > Author of Camel in Action: http://www.manning.com/ibsen/ > > Open Source Integration: http://fusesource.com > > Blog: http://davsclaus.blogspot.com/ > > Twitter: http://twitter.com/davsclaus > > ********************************* This message and any attachments (the "message") are confidential and intended solely for the addressees. 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