Startup Singleton - mareknovotny/seam-migration GitHub Wiki

Seam 2 provides the @Startup annotation that can be applied to an application or session scoped component. A @Startup annotated component is instantiated immediately after the context is started up, instead of instantiating the component lazily when first needed by a client.

There are several alternatives in Java EE 6:

• EJB Singleton beans which can be marked to be instantiated eagerly at application startup using the @Startup annotation. Combined with the fact that these components can benefit from declarative transaction management, these components are good candidates for performing database imports, etc.

• Observing CDI’s 1.1+ built-in events which notify the component when the application starts or when the request or session context is activated due to a servlet request.

• Observing initialization of the ServletContext using the DeltaSpike Servlet module: @Observes @Initialized ServletContext