I'm still trying to get a handle on how to create a simple POJO-based
component that does nothing but receive a message exchange, log the
fact that it received the message exchange, then allows the exact same
message to be passed to the next service in line--if there is one. (Go
grab a cup of coffee, 'cause this is going to take awhile...)
To that end, I have written a handful of components, all of which
resemble this one:
public class NetworkServiceImpl extends ComponentSupport
implements MessageExchangeListener {
private static final Log LOG = LogFactory.getLog(BillingServiceImpl.class);
public NetworkServiceImpl() {}
public void onMessageExchange(MessageExchange exchange)
throws MessagingException {
LOG.info("NETWORK : RECEIVED A MESSAGE");
NormalizedMessage message = exchange.getMessage("in");
LOG.info("NETWORK : DISPATCHING MESSAGE");
InOnly exchange2 = getExchangeFactory().createInOnlyExchange();
exchange2.setInMessage(message);
done(exchange2);
}
}
First of all, this works but is it the correct approach? Or is there a
better way of doing this?
Next, I'd really like to *NOT* extend ComponentSupport or PojoSupport,
as I feel that makes my component not-so-POJO. I'm a bit uncomfortable
with implementing MessageExchangeListener, but I can live with that
because it's an interface and not a class.
So, looking through some of the examples, I see that instead of
extending ComponentSupport (or PojoSupport), I can inject a
ServiceMixClient into my component...so the above class now changes
to:
public class NetworkServiceImpl
implements MessageExchangeListener {
private static final Log LOG = LogFactory.getLog(BillingServiceImpl.class);
public NetworkServiceImpl() {}
public void onMessageExchange(MessageExchange exchange)
throws MessagingException {
LOG.info("NETWORK : RECEIVED A MESSAGE");
NormalizedMessage message = exchange.getMessage("in");
LOG.info("NETWORK : DISPATCHING MESSAGE");
InOnly exchange2 = client.createInOnlyExchange();
exchange2.setInMessage(message);
client.done(exchange2);
}
private ServiceMixClient client;
public void setClient(ServiceMixClient client) {
this.client = client;
}
}
This makes me feel better. But I can't get it to work, because I can't
seem to come up with the correct Spring wiring to inject the
client. I've tried this:
<container id="jbi">
<component id="network"
service="foo:network"
endpoint="network"
class="com.habuma.telco.sm.components.NetworkServiceImpl"
destinationService="foo:install"
destinationEndpoint="install">
<property name="client" ref="client" />
</component>
</container>
<bean id="client"
class="org.servicemix.client.DefaultServiceMixClient" >
<constructor-arg ref="jbi" /> <!-- References the container above -->
</bean>
But when I start up my context, Spring complains of a circular
reference (because "jbi" contains "network" which references "client"
which references "jbi" which contains "network" which...). I tried to
do a lazy-init on the "client" bean, but that didn't help much either
(different error, similar circular reference reason for the error).
In all of the packaged examples that contain a "client" bean, I don't
see any of them actually injecting the client into a component as I've
done above. So this makes me question if I'm taking the right approach
or not.
Any help that anyone can provide will be great.
Thanks,
Craig
