Implementing the EJB 2.1 Component Interfaces

Implementing the Remote Component Interface

The remote interface defines the business methods that a remote client can invoke. The requirements for developing the remote component interface include:

• The remote component interface of the bean must extend the javax.ejb.EJBObject interface, and its methods must throw the java.rmi.RemoteException exception.

• You must declare the remote interface and its methods as public for remote clients.

• The remote component interface, all its method parameters, and return types must be serializable. In general, any object that is passed between the client and the EJB must be serializable, because RMI marshals and unmarshalls the object on both ends.

• Any exception can be thrown to the client. Runtime exceptions, including EJBException and RemoteException, are transferred back to the client as remote runtime exceptions.

• A remote component interface can throw user specified application exceptions.

Example 13-3 shows the remote component interface corresponding to the EJB 2.1 CMP entity bean in Example 13-1 and Example 13-7 shows the remote component interface corresponding to the EJB 2.1 BMP entity bean in Example 13-5.

Implementing the Local Component Interface

The local component interface defines the business methods of the bean that a local (collocated) client can invoke. The requirements for developing the local component interface include:

• The local component interface of the bean must extend the javax.ejb.EJBLocalObject interface.

• You declare the local component interface and its methods as public.