Entity beans’ home interfaces (local and remote) are
used to create, locate, and remove objects from EJB systems. Each
entity bean has its own
remote
or local home interface. The home interface defines two basic kinds
of methods: zero or more create methods, and one or more find
methods. In this example, the create methods act like remote
constructors and define how new Ship EJBs are created. The find
methods are used to locate a specific Ship or Ships. The following
code contains the complete definition of the
ShipHomeRemote
interface:
package com.titan.ship; import javax.ejb.EJBHome; import javax.ejb.CreateException; import javax.ejb.FinderException; import java.rmi.RemoteException; import java.util.Collection; public interface ShipHomeRemote extends javax.ejb.EJBHome { public ShipRemote create(Integer id, String name, int capacity, double tonnage) throws RemoteException,CreateException; public ShipRemote create(Integer id, String name) throws RemoteException,CreateException; public ShipRemote findByPrimaryKey(Integer primaryKey) throws FinderException, RemoteException; public Collection findByCapacity(int capacity) throws FinderException, RemoteException; }
Enterprise JavaBeans specifies that create methods in the home
interface must throw the
javax.ejb.CreateException
. This provides the EJB
container with a common exception for communicating problems
experienced during the create process.
The RemoteException
is thrown by all remote
interfaces and is used to report network problems that occurred while
processing invocations between a remote client and the EJB container
system.