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Eager / auto loading of EJB / load EJB on startup (on JBoss)

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EJBs seem to be loaded lazily - whenever accessed.

However, I want to initialize them eagerly - i.e. whenever the container starts-up. How is this achieved (in JBoss in particular)

This topic gives some hints, but isn't quite satisfactory.

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Bozho Avatar asked Apr 25 '10 09:04

Bozho


2 Answers

As of EJB 3.1, singleton beans can be notified of module start and stop:

@Singleton @Startup public class StartupBean {     @PostConstruct     private void postConstruct() { /* ... */ }      @PreDestroy     private void preDestroy() { /* ... */ } } 

Prior to EJB 3.1, there is no standard, EJB-only solution. I'd suggest adding a WAR to your EAR and using a servlet-context-listener.

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Brett Kail Avatar answered Nov 11 '22 02:11

Brett Kail


According to Adam Bien's Real World Java EE Patterns - Rethinking Best Practices (see a summary of the patterns) and the Service Starter pattern, it is indeed as bkail suggests

  • with Java EE 6 = EJB 3.1 use @Singleton with @Startup (and perhaps also with @DependsOn)
  • prior to that the only standard and portable way is to use the Servlet API, e.g. a HttpServlet starting the EJBs in its init() method and load-on-startup set to 1 in web.xml.
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Jakub Holý Avatar answered Nov 11 '22 04:11

Jakub Holý