Entity beans in java

Basic Information of Entity Beans And Also It's Example

1. ENTITYBEANINJAVA
HirenJamod
Department Of ComputerScience
SaurastraUniversity-Rajkot

2. ENTITY BEANS
Enterprise Beans which represent persistent
data stored in a storage medium, such as a
relational database.
Persists across multiple sessions and can be
accessed by multiple clients.
Each instance of the entity bean represent a row
in the table
EJB container creates instances of an entity bean
and is responsible for loading data in an instance
and storing the information (data) back into the
database.

3. ENTITY BEANS
The persistent mechanisms that enable you to
perform these database manipulations, such as
serialization, Object/Relationship (O/R) mapping
to a relational database and support for JDBC
are built-in the entity bean model

4. CHARACTERISTICS
Persistence
Implies that its state exists even after a client stops
accessing an application
The persistent data remain intact even after the
storage shuts down
Shared Access
Multiple clients can share one entity bean by using
separate instances of the entity bean
EJB Container maintains data consistency by
synchronizing entity bean instances with the
database
To maintain data consistency, the entity beans work
within a transaction

5. CHARACTERISTICS
Primary Key
Each Entity bean has unique identifier; is known
as Primary Key that enables the client to locate
the exact entity bean
Relationships
Like the data of a relational database, the entity
beans are also elated to each other

6. LIFE CYCLE OF ENTITY BEANS

7. LIFE CYCLE OF ENTITY BEANS
Initially, the beans do not exist
When the Application server this stage to the Pooled
stage
When the server is first started, several bean
instances are created and placed in the pool.
A bean instance in the pooled state is not ties to
particular data
At this stage, the beans are referred as passivated.
The bean remains in this stage till the client does
not make a request for it or the container does not
activate it.

8. LIFE CYCLE OF ENTITY BEANS
The bean’s business methods can be invoked
when the bean is at the ready stage.
It remains at this stage till the client calls its
remove method or the container passiveness it if
the bean has been lying idle for sometimes

9. EJB SOURCECODE
Home Interface (extends EJBHome)
Create -Find (for Entity)
Factory Pattern
Remote Interface (EJBObject)
“Business Methods”
Proxy Pattern
Bean Class (EntityBean)
Deployment descriptor (ejb-jar.xml)

10. CRAETEAPPLICATION

11. GIVENAMEOFCRAETEAPPLICATION

12. ADDSESSIONBEAN

13. GIVENAMEOFSESSIONBEAN

14. ADDPERSISTENCEUNIT

15. GIVENAMEPERSISTENCEUNIT

16. ADDENTITYCLASS

17. ADDREFERENCE INTOWEB.XML

18. DECLERINTERFACE

19. DEFINEINTERFACE ANDOVERRIDE
METHOD

20. DEFINEENTITYBEANCLASS

21. DEFINEINDEXPAGE

22. DEFINEINDEXPAGE

23. DEFINEINDEXPAGE

24. DEFINEINDEXPAGE

25. SPECIALTHANKST0 AMITSIR
TOGIVEMEOPPORTUNITY TOREPRESENT MY
PRESENTATION.
BYHIRENJAMOD