Handling of inbound jms messages is more or less clear, just as you said, using "selector" or "messageSelector" fields. If I understood right the selector can contain expressions with message header or message property values.

But what would be the right way to set those values when sending jms messages using either jca-jms or camel-jms reference bindings?

I guess when one needs to set a message header or message property he cannot use the reference defined with @Inject @Reference MyService but rather should use ReferenceInvoker because otherwise there is no access to those fields. Is that correct?

Or should one use the custom MessageComposer instead for setting those values for outgoing jms messages?

Btw, what is the meaning of "Selector" field in JMS reference binding in SY editor?

Yes, that's what I thought as well... but for me more important is other questions about how to specify values on outbound messages in SY, which are later used in selectors. Any hints?

Yes. So, two approaches worked for me (when doing this from a Bean).

1) using ReferenceInvoker:

  @Inject

  @Reference("MyService")

  private ReferenceInvoker myService;

  @Override

  public void foo() throws Exception {

    ReferenceInvocation ri = myService.newInvocation();

    ri.setProperty("customHeaderName", "customHeaderValue");

    ri.invoke(n);

  }

2) using custom JMSMessageComposer:

  public class MyCustomComposer extends JMSMessageComposer {

    @Override

    public JMSBindingData decompose(Exchange exchange, JMSBindingData target) throws Exception {

      exchange.getContext().setProperty("customHeaderName", "customHeaderValue", Scope.MESSAGE);

      target = super.decompose(exchange, target);

      return target;

    }

  }

Any hints which one would be more preferable or is it a matter of personal taste? or what other alternatives exist?