1. Copyright © 2002 Systek ASbrodwall@systek.no Workshop SCEA for J2EE

2. Copyright © 2002 Systek ASbrodwall@systek.no Goals Look through the information needed for the certification Discuss questions for part I and problems for part II Evaluate the presenter’s approach to part II

3. Copyright © 2002 Systek ASbrodwall@systek.no SCEA Del I Common architectures Legacy Connectivity Enterprise JavaBeans Enterprise JavaBeans Container Model Protocols Applicability of J2EE Design Patterns Messaging I18N Security

4. Copyright © 2002 Systek ASbrodwall@systek.no SCEA Del II Create UML diagrams Sequence or collaboration Class Component For Use Cases Prepare Itinerary Change Itinerary Price Itinerary Pay for Itinerary

5. Copyright © 2002 Systek ASbrodwall@systek.no Common Architectures Non-functional attributes Reliability Availability Scalability Extensibility Maintainability Application architecture Single tier/standalone Two tier/client server Multi-tier (web or three-tier)

6. Copyright © 2002 Systek ASbrodwall@systek.no Legacy Connectivity CORBA (RMI-IIIOP) Mainframe (Screen scraping or object mapping) JNI XML Advantages and drawbacks

7. Copyright © 2002 Systek ASbrodwall@systek.no EJB Bean consists of one class and two interfaces Home and remote interface Methods to be used are defined in remote and class Local EJBs versus Remote EJBs Transactions (ACID)

8. Copyright © 2002 Systek ASbrodwall@systek.no Services provided by the container Security Persistence (for Entity Beans) Life Cycle Management (know these) Transaction monitoring Pooling

9. Copyright © 2002 Systek ASbrodwall@systek.no Protocols HTTP (connection-oriented, session-less, easy to get through firewalls, default port 80) HTTPS (connection-oriented, session-oriented, somewhat easy through firewalls, secure, default port 443) JRMP (Procedure-calls, hard to get through firewalls, default port 1099) IIOP (CORBA, cannot marshal “behaviour” only state)

10. Copyright © 2002 Systek ASbrodwall@systek.no Applicability of J2EE Large-scale Transactional! Security Heterogeneous Not always applicable! Especially not EJBs!

11. Copyright © 2002 Systek ASbrodwall@systek.no Design Patterns Know the intent of all patterns Creational Factory Method, Abstract Factory, Builder, Prototype, Singleton Structural Adapter, Bridge, Composite, Decorator, Façade, Flyweight, Proxy Behavioral Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor

12. Copyright © 2002 Systek ASbrodwall@systek.no Messaging What is the difference between Asynchronous and Synchronous communication (in general)? “Queue” vs “Topic” Queue: Point-to-Point (one receiver per message) Topic: Publish subscribe (many receivers per message) Common usage (workflow processes, events (e.g. ticker), integration) Disconnected usage Transactional queues

13. Copyright © 2002 Systek ASbrodwall@systek.no Internationalization Data input/output Data formatting Localizing content and presentation

14. Copyright © 2002 Systek ASbrodwall@systek.no I18N (cont) Typical question: What must be internationalized? (Usually: All of the above) Messages to users, number/date formatting, currencies, images (icons), sounds and other data (Depends upon how far you’re moving) Typical question: What features of Java support I18N? Unicode (char and String), Conversion (Reader and Writer classes), Formatting and Collation (java.text.*), ResourceBundles. The role of the Locale class

15. Copyright © 2002 Systek ASbrodwall@systek.no Security Security concepts Authentication Authorization Confidentiality Digital signatures and encryption technology Certificates (PKI)

16. Copyright © 2002 Systek ASbrodwall@systek.no Security (cont) Java Security/trust model What is applet signing (how does it work?) What can an applet do/not do/do when signed? Firewalls Packet filter Application-level proxy Stateful packet inspection

17. Copyright © 2002 Systek ASbrodwall@systek.no What to expect on the exam Many “scenario questions” The customer suggested this, is that a good idea? What problems arise? How is EJBs applicable here? Many EJB tricky questions Some “what is the job of the architect” Always: To produce the system that the customer needs!!

18. Copyright © 2002 Systek ASbrodwall@systek.no SCEA for J2EE part II Fly-by-Night Integrated with payment backend Integrated with Frequent Flyer backend Web front-end for e-commerce orders Somewhat weird use-cases

19. Copyright © 2002 Systek ASbrodwall@systek.no Use Case Overview

20. Copyright © 2002 Systek ASbrodwall@systek.no Example Screenshot

21. Copyright © 2002 Systek ASbrodwall@systek.no

22. Some questions How many destinations should be supported in one itinerary? Should Itineraries be stored in the DB before they are paid? If not, where? Should seats be reserved before an itinerary is paid? (When should seats be reserved?) Should a user be able to change itinerary after he has paid?

23. Copyright © 2002 Systek ASbrodwall@systek.no Weird Use Case: Change Itinerary After the original is paid? Should original be refunded? What if creating new or refunding old fails?

24. Copyright © 2002 Systek ASbrodwall@systek.no Other questions: How much detail? (Fowler “Specification Level”) What to put in the class diagram (Home, Remote interfaces? Value Object classes) What to put in the component diagram?

25. Copyright © 2002 Systek ASbrodwall@systek.no Example Component diagram:

26. Copyright © 2002 Systek ASbrodwall@systek.no Some links http://groups.yahoo.com/group/scea_j2ee/ http://groups.yahoo.com/group/scea_j2ee/files/SCE A-Nutshell/http://groups.yahoo.com/group/scea_j2ee/files/SCE A-Nutshell/ http://groups.yahoo.com/group/scea_j2ee/files/SCE A%20Quick%20Reference.dochttp://groups.yahoo.com/group/scea_j2ee/files/SCE A%20Quick%20Reference.doc http://suned.sun.com/US/certification/java/java_archj 2ee.htmlhttp://suned.sun.com/US/certification/java/java_archj 2ee.html