Custom Spring Bean Parameters

Question

I'm using the Spring Akka example posted on activator to create Spring managed bean actors. This is the code I'm currently using including a demo class:

@Component
class Test extends UntypedActor {

    @Autowired
    protected ObjectMapper objectMapper;

    protected final Account account;
    protected final Order order;

    public Test(Account account, Order order) {
        this.account = account;
        this.order = order;
    }

    @Override
    public void onReceive(Object message) throws Exception {
        if (message instanceof SomeCommand) {
            // Do something using the order and the account;
        } else if (message instanceof FooCommand) {
            // More stuff
        }
    }
}

@Component
public class SpringExtension extends AbstractExtensionId<SpringExtensionImpl> implements ExtensionIdProvider {

    @Autowired
    private ApplicationContext applicationContext;

    @Override
    public SpringExtensionImpl createExtension(ExtendedActorSystem system) {
        return applicationContext.getBean(SpringExtensionImpl.class);
    }

    @Override
    public ExtensionId<? extends Extension> lookup() {
        return applicationContext.getBean(SpringExtension.class);
    }

}

@Component
public class SpringExtensionImpl implements Extension {

    @Autowired
    private ApplicationContext applicationContext;

    public Props props(String actorBeanName) {
        return Props.create(SpringActorProducer.class, applicationContext, actorBeanName);
    }

}

public class SpringActorProducer implements IndirectActorProducer {

    private final ApplicationContext applicationContext;
    private final String actorBeanName;

    public SpringActorProducer(ApplicationContext applicationContext, String actorBeanName) {
        this.applicationContext = applicationContext;
        this.actorBeanName = actorBeanName;
    }

    @Override
    public Actor produce() {
        return (Actor) applicationContext.getBean(actorBeanName);
    }

    @Override
    public Class<? extends Actor> actorClass() {
        return (Class<? extends Actor>) applicationContext.getType(actorBeanName);
    }

}

Now my question is, how do instantiate an actor with custom constructor arguments. I have thought about using a factory or setter methods but I don't think this is an option since the underlying Actor class is not accessible I believe. Any input on this matter is greatly appreciated. If something is now clear, please post a comment.

PS. If you believe my there is an error in my code or there is a better way of going about it, please do tell me! I have little experience with Spring and Akka combined so any advice is appreciated.

Answer 1

You could pass the additional arguments as varargs (Object...) to SpringExtensionImpl and SpringActorProducer. So your code would look like this:

@Component
public class SpringExtensionImpl implements Extension {

   @Autowired
   private ApplicationContext applicationContext;

   public Props props(String actorBeanName, Object... args) {
       return (args != null && args.length > 0) ?
            Props.create(SpringActorProducer.class,
                    applicationContext,
                    actorBeanName, args) :
            Props.create(SpringActorProducer.class,
                    applicationContext,
                    actorBeanName);
    }
}

public class SpringActorProducer implements IndirectActorProducer {

    private final ApplicationContext applicationContext;
    private final String actorBeanName;
    private final Object[] args;

    public SpringActorProducer(ApplicationContext applicationContext, String actorBeanName) {
        this.applicationContext = applicationContext;
        this.actorBeanName = actorBeanName;
        this.args = null;
    }

    public SpringActorProducer(ApplicationContext applicationContext, String actorBeanName, Object... args) {
        this.applicationContext = applicationContext;
        this.actorBeanName = actorBeanName;
        this.args = args;
    }

    @Override
    public Actor produce() {
        return args == null ? 
              (Actor) applicationContext.getBean(actorBeanName):
              (Actor) applicationContext.getBean(actorBeanName, args);
    }

    @Override
    public Class<? extends Actor> actorClass() {
        return (Class<? extends Actor>) applicationContext.getType(actorBeanName);
    }

}

You can then create your Test actor like this:

SpringExtensionImpl springExtensionImpl; actorSystem.actorOf(springExtensionImpl.create(Test.class, account, order));