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86 Chapter 8. Developing Entity Beans
•
public void
ejbPassivate
();
The container invokes this method on an instance before the instance becomes dissociated with
a specific EJB object. After this method completes, the container will place the instance into the
pool of available instances.
•
public void
ejbRemove
();
This method is invoked by the container when a client invokes a remove operation on the Enter-
prise Bean. For entity beans with
bean-managed persistence
, this method should contain
the JDBC code to remove the corresponding data in the database. For
container-managed
persistence
, this method is called before the container removes the entity representation in
the database.
•
public void
ejbLoad
();
The container invokes this method to instruct the instance to synchronize its state by loading it
from the underlying database. For
bean-managed persistence
, the EJB provider
should code at this location the JDBC statements for reading the data in the database. For
container-managed persistence
, loading the data from the database will be done
automatically by the container just before ejbLoad is called, and the ejbLoad method should
only contain some “after loading calculation statements.”
•
public void
ejbStore
();
The container invokes this method to instruct the instance to synchronize its state by storing
it to the underlying database. For
bean-managed persistence
, the EJB provider should
code at this location the JDBC statements for writing the data in the database. For entity beans
with
container-managed persistence
, this method should only contain some “pre-store
statements,” since the container will extract the container-managed fields and write them to the
database just after the ejbStore method call.
8.5.1. Enterprise Bean Class Example
The following examples are for container-managed persistence with EJB 1.1 and EJB 2.0. For bean-
managed persistence, refer to the examples delivered with your specific platform.
8.5.1.1. CMP 1.1
package eb;
import java.rmi.RemoteException;
import javax.ejb.EntityBean;
import javax.ejb.EntityContext;
import javax.ejb.ObjectNotFoundException;
import javax.ejb.RemoveException;
import javax.ejb.EJBException;
public class AccountImplBean implements EntityBean {
// Keep the reference on the EntityContext
protected EntityContext entityContext;
// Object state
public Integer accno;
public String customer;
public double balance;
public Integer ejbCreate(int val_accno, String val_customer,
double val_balance) {