Adapting an EJB 3.0 Stateless Session Bean for an EJB 2.1 Client

By associating an EJB 3.0 stateless session bean with EJB 2.1 home and component interfaces (see "Using Annotations"), you can adapt an EJB 3.0 stateless session bean so that an EJB 2.1 client can access it.

You can use this technique to manage the incremental migration of an EJB 2.1 application to EJB 3.0 or to give existing EJB 2.1 clients access to new development that you implement using EJB 3.0.

For more information on EJB 2.1 home and component interfaces, see the following:

• "Implementing the Home Interfaces"

• "Implementing the Component Interfaces"

Using Annotations

To adapt an EJB 3.0 stateless session bean for an EJB 2.1 client, do the following:

1. Associate the EJB 2.1 home interfaces with the EJB 3.0 stateless session bean.

   Use the @RemoteHome annotation for remote home interfaces, and the @LocalHome annotation for local home interfaces:

   @Stateless
   @RemoteHome (value=Ejb21RemoteHome1.class)
   @LocalHome (value=Ejb21LocalHome.class)
   public class MyStatelessSB {
   ...
   }
   

   Note:

   You may associate a stateless session bean with at most one remote and one local home interface.

2. Consider the requirements for supporting the home interface's create methods.

   An EJB 3.0 stateless session bean does not require an ejbCreate method, even when it has a home interface. Alternatively, you may define a post-construct life cycle callback method (see "Configuring a Life Cycle Callback Interceptor Method on an EJB 3.0 Session Bean").

3. Associate the EJB 2.1 component interfaces with the EJB 3.0 stateless session bean.

   Use the @Remote annotation for remote component interfaces, and the @Local annotation for local component interfaces:

   @Stateless
   @Remote (value={Ejb21Remote1.class, Ejb21Remote2.class})
   @Local (value={Ejb21Local.class})
   public class MyStatelessSB {
   ...
   }
   

   Note:

   You may associate a stateless session bean with one or more remote and local component interfaces.