Enterprise JavaBeans, Fourth Edition

The Remote Home Interface

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 ...