1. Entity Java Beans Jorg Janke http://www.compiere.org Open Source ERP & CRM

2. Objectives Know J2EE & EJB Buzzwords Understanding of J2EE Architecture Understanding of EJB Architecture Know next steps to explore J2EE & EJB

3. Java Application Tiers

4. Java Application Tiers (Detail)

5. J2SE

6. EJB Types Session Beans Stateless Stateful Entity Bean Bean Managed Persistency Container Managed Persistency (CMP) Message Bean

7. Stateless Session Bean

8. Stateful Session Bean

9. Entity Bean

10. Message Bean

11. EJB Source Code Home Interface (extends EJBHome) Create - Find (for Entity) Factory Pattern Remote Interface (EJBObject) “Business Methods” Proxy Pattern Bean Class (EntityBean/SessionBean) Deployment descriptor (ejb-jar.xml)

12. EJB Runtime Home (“create”, “find”) Home Object Stub Home Object EJB (“business methods”) EJB Object Stub EJB Object Bean (“the entity”) Enterprise Bean Object

13. EJB Container - Client Client Container Home Stub Object Stub RMI-IIOP Home Object EJB Object Enterprise Bean Object JNDI

14. EJB Use Context ctx = new InitialContext(); JNDI to LDAP or other Directory Service BeanHome home = ctx.lookup(“myBean"); Container finds/creates Factory BeanRemote bean = home.create(); Container creates EJB Object -> myBean Bean.doSomething(); Business Method “Proxy”

15. Getting started The hard way Download, Install & Implement the J2EE Reference Implementation (Cloudscape) The easy way Select a IDE J2EE support often in “Enterprise Edition” Free: Forte / NetBeans

16. Now you have your IDE … Check what Containers are supported (or included) Download & Install the Container E.g. JBoss includes Tomcat IDEs provide Wizards / Templates Packaging & Deployment

17. For a live demo … visit me

18. JBuilder New …

19. New Module (multiple Beans)

20. New Session Bean

21. Stateless Session Bean

22. Session Bean Properties

23. Home Interface

24. Remote Interface

25. Bean Class

26. Deployment Descriptor

27. Add additional methods …

28. Create Test Client

29. Client 1 – Lookup

30. Client 1 - Create

31. Client 1 – Business Methods

32. Entity Bean

33. Home Interface

34. Remote Interface

35. Bean Class

36. Client 2

37. Client 2 – Lookup / Create

38. Client 2 – Business Methods

39. Java Application Tiers

40. How do EJBs “fit in” Application Server Business Objects Coarse Grained Objects Fine Grained Objects (not suited) Local Interface

41. What is J2EE compliant Server providing Web Services Servlet, JSP JNDI, RMI, JDBC EJB Services EJB with CMP JMS, JTA, JAAS Compliance Test Version 1.2, 1.3, … License Application using One of the technologies Servlet or RMI & JDBC will do

42. When to use EJBs You need a EJB project for your CV Highly shared, long lived objects Entity Beans Container Managed Persistency (CMP) Data Access Object Receiving Messages (JMS) (Simple) Transaction Support (outside JDBC) Security Support

43. Compiere & J2EE Compiere does not use EJBs EJB Container (candidate: JBoss) Additional Installation effort Additional Operation effort Plus: Could be installed automatically Compiere’s Business Objects (Invoice,..) dynamically are generated Based on Data Dictionary Business Objects & Behavior are “personalized”

44. Intro Resources http://java.sun.com/j2ee/ Deployathon http://java.sun.com/blueprints http://java.sun.com/j2ee/tutorial J2EE “community” sites http://www.theserverside.com http://www.middleware-company.com/ http://www.onjava.com (O’Reilly) http://www.onjava.com

45. Thanks You can download the presentation http://www.compiere.org/download My contact: http://www.compiere.com/consulting.html jorg.janke@compiere.org