1. J2EE Architecture Overview
Mark Hapner, Lead Architect J2EE
Bill Shannon, Distinguished Engineer
Sun Microsystems

2. The J2EE Platform Platform Specification Compatibility Test Suite
Defines JavaTM 2 Enterprise Edition (J2EE) requirements
Compatibility Test Suite
Reference Implementation
Validates JavaTM 2 Enterprise Edition (J2EE) compatibility
Operational JavaTM 2 Enterprise Edition (J2EE)
J2EE Blueprints
Describes how to build JavaTM 2 Enterprise Edition (J2EE) applications

3. Write Once, Run Anywhere
Develop
With J2EE components
Package
Universal J2EE application package
Deploy & Run
On any J2EE product

4. J2EE Components and Containers
Applet Container
Web Container
EJB Container
Applet
HTTP/ HTTPS
JSP
Servlet
RMI
EJB
J2SE
JavaMail
JavaMail
JTA
RMI/IIOP
JDBC
JMS
JNDI
JMS
JTA
JNDI
RMI/IIOP
JDBC
App Client Container
JAF
JAF
App Client
HTTP/ HTTPS
J2SE
RMI
JNDI
JMS
RMI/IIOP
JDBC
J2SE
J2SE
Database

5. JSP/Servlet Overview Java Server Pages Servlets
Merges HTML/XML template with content dynamically generated with Java
Extensible tag libraries
Source is dynamically compiled on first use
Servlets
Implement dynamic content with Java
Built-in support for session and request management

6. EJB Overview EJB Session Bean Entity Beans
Each EJB is an multi-user, transacted `service'
Session Bean
Implements a `tool' or `application' service
Entity Beans
Implements a service of long lived business entities
Container Managed Transactions
Automatically wraps a method in a transaction

7. Session Beans Stateful Session Beans Stateless Session Beans
Container manages client state in a bean's fields
'stateless' model is not forced on developers
Stateless Session Beans
If there is no client state, container optimizes management of EJB instances

8. Entity Beans EJB defines model for 'persistent' beans
Allows container to optimize their management
Makes it easy to create a business object facade
Bean Managed Persistence
Write your own SQL with JDBC/SQLJ
Container Managed Persistence
Container handles moving data to/from bean
Limited facility in EJB 1.1, enhancements in 2.0

9. J2EE Containers Container vs Framework Containers Manage
No complicated APIs
Services are injected
Containers Manage
Threads, transactions, administration, deployment, distribution
May also provide load balancing and fail-over
All with no change to component code

10. Application Packaging
EJB
EJB Module 1
EJB 1
APP DD DD DD
EJB
Web Client Module 2
WEB
Deployment Tool 2
WEB DD DD
Application Client Module 3 3 DD DD

11. Application Life Cycle
Creation
Assembly
Deployment
Created by Component Developer
Assembled and Augmented by Application Assembler
J2EE Modules
J2EE Application
Processed by Deployer
Deploy
J2EE Container
Enterprise Components

12. J2EE Status J2EE 1.2 Shipped 12/17/99
Specifications
Reference Implementation
Compatibility Test Suite
J2EE Blueprints Beta
J2EE Blueprints Book Coming Soon!

13. Some J2EE Partners Allaire IBM Progress Inline BEA/Weblogic Secant
Bluestone
Bull
Forte
Fujitsu
Gemstone
Haht
IBM
Inline
iPlanet
Iona
Luna
Novera
Oracle
Persistence
Progress
Secant
Siemens
SilverStream
Sybase
TradeX
Versant
Vision

14. Some Users of J2EE Air Canada Celera Genomics Countrywide
Covad Communications
Electric Boat
Equifax
FAA
Nations Bank
Qwest
Ratheon
Rorke Data
Scottish Equitable
Sparks.com
Trip.com

15. J2EE Scenarios

16. Book Catalog Browser Database contains catalog
JSP generates catalog pages
Using HTML template
Combined with catalog data

17. Book Purchase Session contains shopping cart data
Orders entered into Orders DB
Purchase transaction programmed with JDBC

18. Book Purchase JSP contains no Java code
Written by presentation expert
JSP Tag Library provides Browse and Purchase
Written by JDBC and database expert

19. Book Purchase Session EJB handles purchase transaction
App Server pools DB connections
App Server manages transactions

20. Book Purchase Book and Order Entity EJBs Persistent business objects
Hide database details

21. Catalog Management App Client for `dedicated' catalog admin
XML `raw' book data
App Client provides more interactive GUI

22. J2EE 1.3 (JSR 58)

23. Connectors (JSR 16)
Standard SPI for integrating J2EE with other systems
CICS, IMS, SAP, PeopleSoft, Baan, etc
Connection pooling
Transactions
Security
Common Client Interface
Standard packaging for resource adapter

24. EJB 2.0 (JSR 19) EJB Entity Container Managed Persistence
Dependent objects, Relationships, Finder query lang
EJB/JMS Integration
Message driven EJB
EJB Interoperability
Home Methods

25. Other Additions XML Parsing API (JSR 5) JSP 1.2/Servlet 2.3 (JSR 53)
JSP Standard Tag Lib (JSR 52)
JMS becomes required

26. More Info http://java.sun.com/j2ee http://java.sun.com/xml