hi all, is it possible to create something like static object using EJB3 in Jboss. in other words i need to create something like a static object using singleton pattern or something like that, that is because i need to preload a configuration from database and i want that every bean that jboss creates uses this class to read this configuration instead of that every bean load it from the database.
Cheers,
Bean with @Singleton annotation should work. Place your database initialize code in @PostConstruct & can release/cleanup in @PreDestroy.
EJB 3.1 does have a standard @Singleton annotation but EJB 3.0 doesn't. However, JBoss offers a JBoss extension to the EJB 3.0 spec to create a singleton with the @Service annotation.
From the JBoss EJB 3.0 Reference Documentation:
Chapter 6. JBoss EJB 3.0 extensions
JBoss provides a few extensions to the EJB 3.0 spec. This chapter describes those features here.
6.1. @Service EJBs
An extension offered by JBoss EJB 3.0 is the notion of a
@org.jboss.annotation.ejb.Serviceannotated bean. They are singleton beans and are not pooled, so only one instance of the bean exists in the server. They can have both@Remoteand@Localinterfaces so they can be accessed by java clients. When different clients look up the interfaces for@Servicebeans, all clients will work on the same instance of the bean on the server. When installing the bean it gets given a JMX ObjectName in the MBean server it runs on. The default isjboss.j2ee:service=EJB3,name=<Fully qualified name of @Service bean>,type=serviceYou can override this default ObjectName by specifying the
objectNameattribute of the@Serviceannotation.