openwebbeans custom resources

cdi itself allows to add beans to integrate other frameworks and containers.
so it's possible to inject them via @Inject.
however, sometimes you need to use other annotations like @EJB or @Autowired.
in an ee-server ee-annotations like @EJB work out-of-the-box. however, in case of a manual setup e.g. in combination with a servlet-container like tomcat, you might not be able to inject references to remote-ejbs. in any case you can't use non-ee annotations like @Autowired in cdi-beans out-of-the-box.

as mentioned in previous posts apache openwebbeans is very flexible.

owb is based on a simple plugin architecture which allows to customize parts easily.

some years ago i published an add-on for owb which allows to inject remote-ejbs via @EJB into cdi-beans in non-ee environments.

the add-on injects references resolved by a custom ejb-resolver into injection-points annotated with @EJB.

with the same approach it's possible to use 3rd party annotations in cdi-beans.

today i prototyped a similar add-on for owb, which allows to use @Autowired in cdi-beans to inject spring-beans based on the (field-)name or type. compared to the cdi-spring bridge i described here, it allows a simpler implementation which delegates to a started spring-container (instead of bootstrapping it). the major downside is that it isn't a portable cdi-extension (per definition) and therefore you can only use it with owb. furthermore, there is no validation of those injection-points during the startup you (might) know from cdi and injection of cdi-beans into spring-beans isn't supported as well.

[add-on] owb and actors

actor-frameworks for the jvm gain more popularity every day. even with actor-frameworks you have to be careful with shared state. however, if you have a java-ee application, you can (re-)use stateless services in your actors easily. one use-case is to resolve transactional beans (ejbs, cdi-beans which are annotated e.g. with @Transactional, ...) in an actor and invoke methods on them to access a database.

with an ee-application-server like tomee that works out-of-the-box. you just have to bootstrap an actor-framework (like akka, jetlang,...) and use the std. java-ee api to lookup the bean/s.

if you are interested in using transactional cdi beans, you can use the jpa-module provided by apache deltaspike v0.4+ (note: those transactions don't span across actors). for using @Transactional, you just have to follow the documentation and you are done. that's usually a short story. but...

if you would like to use @Singleton or @ApplicationScoped beans and you are using the openwebbeans-web module of owb v1.1.x, you need an additional plugin (due to OWB-785). in such cases just get https://github.com/os890/owb-contexts_service-addon.git, build it and add it as runtime dependency to your project.
-> you are done (there is no additional api you have to use).

additional hint:
apache deltaspike provides some nice helpers (like BeanProvider#getContextualReference to resolve cdi-beans), interceptors (like @Transactional), scopes (like @TransactionScoped) and much more...