1. Introduction to Enterprise JavaBean
Tearina Chu
Denise Mangano
Vivek Rudrapatna
Team 11
11/22/2018
Team 11-EJB

2. Outline All about EJB fundamentals What is EJB What’s it’s structure
What’s it’s components
What’s the interactions between client and server
What’s the technology used behind
Why use EJB
11/22/2018
Team 11-EJB

3. Enterprise Java Beans
Java Beans
11/22/2018
Team 11-EJB

4. Enterprise JavaBean Specification of server-side component market
Enable you to purchase off the shelf components from one vendor, combine them with components from another vendor, and run those component in an application server written by a third vender.
Enable you BUY, rather than BUILD elements of server-side applications.
11/22/2018
Team 11-EJB

5. Component Architecture
A component architecture for deployable server-side components in Java.
Buy small modules to solve small problems
Combine a number of modules to solve a large problem
11/22/2018
Team 11-EJB

6. Divide and Conquer
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7. Top three values of EJB It agreed upon by the industry
Portability is easier
Rapid application development
11/22/2018
Team 11-EJB

8. The parties of EJB
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9. EJB deployment
11/22/2018
Team 11-EJB

10. Types of Beans Session beans Entity beans Message-driven beans
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11. 11/22/2018
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12. Distributed objects
11/22/2018
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13. Distributed Objects Remote interface Local /remote transparency
The client call a stub, which is a client-side proxy object
The stub calls ovver the network to a skeleton, which is a server-side proxy object.
The skeleton delegates the call to the distributed object.
Remote interface
Local/remote transparaency
11/22/2018
Team 11-EJB

14. Implicit Middleware
11/22/2018
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15. What constitutes an Enterprise Bean
The Enterprise Bean class
The EJB object
The remote interface
The home object
The local interfaces
11/22/2018
Team 11-EJB

16. The Enterprise Bean class
For session beans: business-process-related logic
For entity beans: data-related logic
For message-driven beans: message-oriented logic
11/22/2018
Team 11-EJB

17. The EJB Object Indirection between the client and the bean
Knowledge about networking, transaction, security, and more.
Invocation is intercepted by the EJB container and then delegated to the bean instance (request interception)
11/22/2018
Team 11-EJB

18. EJB Objects - cont. The Remote Interface Written by the bean provider
Clone every business method that your bean classes expose
Must derive from a common interface supplied by Sun Microsystems, called javax.ejb.EJBObject
A number of methods must be implemented, not by you, but the EJB container
11/22/2018
Team 11-EJB

19. The EJB Object
11/22/2018
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20. The Home Object Acquire references to EJB objects Perform
Create EJB objects
Find existing EJB objects
Remove EJB objects
11/22/2018
Team 11-EJB

21. The Home Object
11/22/2018
Team 11-EJB

22. The local interface Save a lot of overhead over remote interface
Client calls a local object
Local object performs needed middleware
Once the enterprise bean instance does its work, it returns control to the local object, which then returns control of the client
11/22/2018
Team 11-EJB

23. Deployment Descriptors
Declare the components’ middleware service requirements by a bean provider
Commonly XML files
11/22/2018
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24. EJB-Jar File Bean classes Home interfaces Remote interfaces
Deployment descriptor
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25. Why Use EJB Shelf products Reuse Easy to write Easy to maintain
Easy to support
Focus on business logic
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26. 11/22/2018
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