Hello,

I am trying to figure out how to use just one singleton bean that "lives" on a cluster. I have found an approximation of that using HA singleton (example from wildfly/quickstart · GitHubhttps://github.com/wildfly/quickstart).

Basically that solution is to have a service running in only one machine of a cluster. This service has a method, getValue(), wich allows to call a singleton bean, guaranteeing that

there is only one singleton bean instance inside the cluster.

The problem with that approach, is that the getValue() method of the service invokes a singleton bean and allows to call to one method. Untill here, all good. But, what happen if the singleton bean I want to invoke has more than one method? The idea is not to implement several services per each method that I need to invoke.

The basic idea (according the quickstart ha singleton example) is, from the client, call to a @Stateless bean (AccessBean) that calls the Service... I implemented something like that :

     //from my @stateless accessBean

    ServiceController<?> service = CurrentServiceContainer.getServiceContainer().getService(MyService.DEFAULT_SERVICE_NAME);

where MyService implements org.jboss.msc.service.Service<SomeType>

then, we can call :

      //from my @stateless accessBean

     service.getValue();

this returns an object and it works fine.

The getValue() implementation (as a part of the Service) is something like that:

** I omitted all the try/catch/throws exception, is just a  code to explain the problem **

   @Override

    public Integer getValue() {

            InitialContext ic = new InitialContext();

            Integer gvalue = ((MyRemoteInterface) ic.lookup("global/....!....")).getValue(); //that calls a method from the singetonBean

            return gvalue;

     }

I tried to create a new getValue method that have parameters inside my  MyService Class (for example the name of the method I want to invoke, using reflection) and when I try to use this method from my @Stateless bean (AccessBean) as in this line:

  ((MyService)service).getValue(some parameteres...)

I have a java.lang.ClassCastException because service's class is org.jboss.msc.service.ServiceControllerImpl and is not possible to cast with my service.

Please, any Idea ?

Thanks!