Configuring Atmosphere's Classes Creation and Injection

Starting with Atmosphere 2.1, it is possible to configure a AtmosphereObjectFactory and configure Atmosphere to use it. You can define your own and pass it to the framework by defining an init-param:

<init-param>
  <param-name>org.atmosphere.cpr.objectFactory</param-name>
  <param-value> << an implementation of AtmosphereObjectFactory >> </param-value>
</init-param>

Using Contexts and Dependency Injection (CDI)

By default, Atmosphere will use the following code for injecting/creating object:

public class CDIObjectFactory implements AtmosphereObjectFactory {
    @Override
    @SuppressWarnings("unchecked")
    public <T> T newClassInstance(AtmosphereFramework framework, Class<T> classToInstantiate) throws InstantiationException, IllegalAccessException {
        CreationalContext cc = null;

        final BeanManager bm;
        try {
            bm = (BeanManager) new InitialContext().lookup("java:comp/BeanManager");
            final Iterator<Bean<?>> i = bm.getBeans(classToInstantiate).iterator();
            if (!i.hasNext()) {
                return classToInstantiate.newInstance();
            }
            Bean<T> bean = (Bean<T>) i.next();
            CreationalContext<T> ctx = bm.createCreationalContext(bean);
            T dao = (T) bm.getReference(bean, classToInstantiate, ctx);
            return dao;
        } catch (Exception e) {
            // Log ME. Fallback to normal.
            return classToInstantiate.newInstance();
        } finally {
            if (cc != null) cc.release();
        }
    }
}

You can install it by adding in your pom.xml:

 <dependency>
    <groupId>org.atmosphere</groupId>
    <artifactId>atmosphere-cdi</artifactId>
    <version>2.1.0</version>
</dependency>

Atmosphere will auto-detect it and use it automatically.

Using Spring

By default, Atmosphere will use the following code for injecting/creating object:

public class SpringObjectFactory implements AtmosphereObjectFactory {
    @Override
    public <T> T newClassInstance(AtmosphereFramework framework, Class<T> tClass) throws InstantiationException, IllegalAccessException {
        ApplicationContext context =
            new AnnotationConfigApplicationContext(classToInstantiate);
        T t = context.getBean(classToInstantiate);
        if (t == null) {
            logger.info("Unable to find {}. Creating the object directly.", classToInstantiate.getName());
            return classToInstantiate.newInstance();
        }
        return t;
    }
}

You can install it by adding in your pom.xml:

 <dependency>
    <groupId>org.atmosphere</groupId>
    <artifactId>atmosphere-spring</artifactId>
    <version>2.1.0</version>
</dependency>

Using Guice

By default, Atmosphere will use the following code for injecting/creating object:

public class GuiceObjectFactory implements AtmosphereObjectFactory {
    private static final Logger logger = LoggerFactory.getLogger(GuiceObjectFactory.class);
    private static Injector injector;
    static {
        injector = Guice.createInjector(new AbstractModule() {
            @Override
            protected void configure() {
            }
        });
    }

    @Override
    public <T> T newClassInstance(AtmosphereFramework framework, Class<T> classToInstantiate) throws InstantiationException, IllegalAccessException {
        com.google.inject.Injector servletInjector = (com.google.inject.Injector)
                framework.getServletContext().getAttribute(com.google.inject.Injector.class.getName());

        if (servletInjector != null) {
            injector = servletInjector;
        }

        if (injector == null) {
            logger.warn("No Guice Injector found in current ServletContext. Are you using {}", AtmosphereGuiceServlet.class.getName());
            logger.trace("Unable to find {}. Creating the object directly.", classToInstantiate.getName());
            return classToInstantiate.newInstance();
        }
        return injector.getInstance(classToInstantiate);
    }
}

You can install it by adding in your pom.xml:

 <dependency>
    <groupId>org.atmosphere</groupId>
    <artifactId>atmosphere-guice</artifactId>
    <version>2.1.0</version>
</dependency>