Thanks for the excellent documentation Clement!
But, I still have one question...
Now, if I use @ServiceController I want to explicitly start my underlying
service (my Camel route) before iPOJO publishes the service for others to
consume. Starting the route in the @PostRegistration callback is therefore
too late.
When using the @Controller I usually connect the life cycle controller to a
property managed by config admin, like so:
@Controller
@Property(name = "enabled", mandatory = true)
private boolean mValid;
I then start my underlying service (my Camel route) in the @Validate
callback, like so:
@Validate
public void start() {
// Start Camel route
}
and stop it like so:
@InValidate
public void stop() {
// Stop Camel route
}
When using @ServiceController what would be the equivalent? Somthing like
this?
@ServiceController(value=false)
private boolean mValid;
@Property(name = "enabled", mandatory = true)
public void setValid(boolean theValid) {
if(theValid) {
// Start Camel route
}
mValid = theValid;
}
@PostRegistration
// Stop Camel route
}
What I want to accomplish is to make sure that the underlying service (the
Camel route) is running for as long as the service is published to others.
/Bengt
2013/10/7 Clement Escoffier <[email protected]>
> Hi,
>
>
> On 4 oct. 2013, at 10:04, Bengt Rodehav <[email protected]> wrote:
>
> > I discussed this with Clement on another thread ("iPOJO and dynamic
> > requires") but thought I'd start a new thread that better describes the
> > subject.
> >
> > A little background...
> >
> > Using iPOJO (currently 1.8.6), I have a system where I'm using a
> > life-cycle-controller (@Controller) to enable(start) / disable(stop) my
> > services. A lot of the services are Camel routes that are then started
> and
> > stopped by changing a config admin property (in a GUI).
> >
> > Basically the code looks like this:
> >
> > @Controller
> > @Property(name = "enabled", mandatory = true, value = "false")
> > private boolean mValid;
> >
> > @Validate
> > public void start() {
> > System.out.println("Starting... valid is: " + mValid);
> > // Start the Camel route
> > }
> >
> > @Invalidate
> > public void stop() {
> > System.out.println("Stopping... valid is: " + mValid);
> > // Stop the Camel route
> > }
> >
> > On startup, if the "enabled" property is set to false, nothing is logged.
> > When I set the enabled property to true I get:
> >
> > Starting... valid is: true
> >
> > If I then set the enabled property to false I get:
> >
> > Stopping... valid is: false
> >
> > This is the way I want it to work. I use the "enabled" property to
> > start/stop my services.
> >
> > However, I now need to make the life-cycle controller more dynamic. In
> > addition to looking at the "enabled" property I also want to add my
> custom
> > extra constraints. Something like this:
> >
> > private boolean mValid;
> >
> > @Property(name = "enabled", mandatory = true, value = "false")
> > public void setValid(boolean theValid) {
> > System.out.println("Setting valid to: " + theValid);
> > mValid = theValid;
> > mAggregateValid = mValid; // I also add extra constraints not shown
> > here: mAggregateValid = mValid && <extra constraints>
> > }
> >
> > @Controller
> > private boolean mAggregateValid;
> >
> > @Validate
> > public void start() {
> > System.out.println("Starting... mValid is: " + mValid + ",
> > mAggregateValid is: " + mAggregateValid);
> > // Start the Camel route
> > }
> >
> > @Invalidate
> > public void stop() {
> > System.out.println("Stopping... mValid is: " + mValid + ",
> > mAggregateValid is: " + mAggregateValid);
> > // Stop the Camel route
> > }
> >
> > I now get:
> >
> > Starting... mValid is: false, mAggregateValid is: false
> > Stopping... mValid is: false, mAggregateValid is: false
> >
> > This is not the way I wanted. Although I've set the @Controller to
> > "mAggregateValid", the instance is becoming valid when the
> mAggregateValid
> > is false. It does stop shortly afterwards but I get a false start this
> way
> > that gives me problems.
> >
> > Question 1: Why does the instance become valid despite the fact that my
> > life-cycle-controller is false?
>
> Because the instance lifecycle controller does not allowed default value.
>
> >
> > Clement, you suggested that I should use the @ServiceController instead.
> I
> > tried this but it seems like the @Validate callback will be called no
> > matter what value my @ServiceController has. I noticed that there are
> other
> > callbacks that I might be able to use instead: @PostRegistration and
> > @PostUnregistration. However, they seem to be called "after the fact".
> If I
> > use those callbacks to actually start my services it would mean that I
> > first publish a service and afterwards make it work. Should be the other
> > way around.
> >
> > Question 2: For my use case, should I use @Controller or
> @ServiceController
>
> In your case you should use @ServiceController. I've published a new page
> about controllers:
>
> http://felix.apache.org/documentation/subprojects/apache-felix-ipojo/apache-felix-ipojo-userguide/instance-vs-service-controller.html
>
>
> >
> > Looking at the annotations documentation (
> >
> http://felix.apache.org/documentation/subprojects/apache-felix-ipojo/apache-felix-ipojo-gettingstarted/how-to-use-ipojo-annotations.html
> )
> > I noticed that @Controller is not mentioned at all.
> >
> > Question 3: Is @Controller deprecated or does the documentation need to
> be
> > updated?
>
> This is a mistake…. We will add it ASAP.
>
> Regards,
>
> Clement
>
> >
> > When the new version of iPOJO is released I might not need to use an
> > "aggregated controller" but could use interceptors instead (see my
> original
> > thread). But I would still like to know why I can't get the above to work
> > correctly.
> >
> > Thanks,
> >
> > /Bengt
>
>
