问题
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.
回答1:
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.
回答2:
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.
来源：https://stackoverflow.com/questions/2707733/eager-auto-loading-of-ejb-load-ejb-on-startup-on-jboss