Introduction to

1
Welcome!

• Introduction to
• Java 2 Enterprise Edition
• Presented by
• Communication Collaboration Technologies
• Division of the Chief Information Officer
• Rensselaer Polytechnic Institute

2
Main Topics

• Introduction
• The Goal
• The Problem
• The Solution
• What is J2EE?
• Motivations
• The J2EE Framework
• Case Studies / Examples

3
Motivations

• Why J2EE?
• Presentation world is web-centric
• Tried other approaches
• Static HTML, CGI, Applets, ASP
• Need integration with campus-wide services
• Capitalize on developers strengths
• Programming
• Presentation
• DBM
• Framework is being widely adopted by vendors

4
Motivations

• Oracle 9iAS Internet Application Server
  Enterprise Edition used by SCT for Banner
• 100 compliant J2EE server

5
Motivations

• WebSphere continues the evolution to a single
  Web services-enabled, Java 2 Enterprise Edition
  (J2EE) application server and development
  environment that addresses the essential elements
  needed for an on demand operating environment.
• http//www-3.ibm.com/software/info1/websphere
• IBM Globus Project developing grid computing
  with JBoss and IBM WebSphere
• http//www-1.ibm.com/grid/grid_strategy.shtml
• http//www.javaworld.com/javaworld/jw-09-2002/jw-0
  906-grid.html

6
The J2EE Framework
7
J2EE Container

• Component Based Architecture
• Applications are built from components
• Java class files
• Configuration files (usually XML)
• Data files (html, images, directories,)
• Components are packaged into archives for
  deployment
• jar Java Application Resource
• war Web Application Resource
• ear Enterprise Application Resource

8
J2EE Container

• Deploying Applications
• J2EE server specific
• Some provide GUI tools to build and deploy
  applications (WebSphere, BEA WebLogic)
• Some require editing XML configuration files
  (JBoss)
• JBoss
• Drop .ear archive files into a deploy directory
  
• Hot deploy redeploy

9
Java Technologies

• JNDI
• namespaces, ldap
• JDBC
• database connectivity
• JAAS
• authentication
• JTA
• transactions
• JMX
• management monitoring
• JavaMail
• email
• EJB
• business logic data

• JMS
• messaging
• CORBA
• remote procedure calls
• SOAP
• web services
• RMI
• remote method invocation
• Servlets
• web logic
• JSP
• web presentation
• XML
• portability

10
JNDI

• Java Naming Directory Interface
• Provides namespace support for J2EE
• Beans located by name within container namespace
• Application attributes located by name within
  application local namespace
• Controlled access from external servers
• Access to LDAP directories

11
JDBC

• Java DataBase Connectivity
• Java equivalent of ODBC (Open DataBase
  Connectivity)
• Java API that enables Java programs to execute
  SQL statements. This allows Java programs to
  interact with any SQL-compliant database

12
JAAS

• Java Authentication and
• Authorization Service
• Implements a Java version of the standard
  Pluggable Authentication Module (PAM) framework
• Supports user-based authorization
• Access control at every level

13
JTA

• Java Transaction API 1 of 2
• Specifies standard interfaces between a
  transaction manager (e.g. JBoss) and the parties
  involved in a distributed transaction system
• the resource manager
• the application server
• and the transactional applications
• Two types of transaction paradigm
• Declarative for entity session beans
• Programmatic for session beans servlets

14
JTA

• Java Transaction API 2 of 2
• Provides ACID transaction support
• Atomicity
• Consistency
• Isolation
• Durability

15
JMS

• Java Message Service
• Point to point messaging
• each message has only one consumer
• used to decouple applications
• Publish/subscribe messaging
• each message may have multiple consumers

16
EJB

• Enterprise Java Bean
• Bean
• originally a Java class with get() and set()
  methods
• e.g. getFirstName(), setFirstName()
• EJBs come in 3 flavors

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EJB Entity Bean

• Entity Bean
• Represent actual data items (e.g. rows in a
  result set)
• Two forms of Entity Bean
• Container managed persistence DB interactions
  handled by the J2EE environment
• Bean managed persistence requires that the bean
  carries out DB interactions itself
• May be called across network connection (RMI)

18
EJB Session Bean

• Session Bean
• Model a process or task
• Represent resources private to the client
• May update shared data
• Two forms of Session Bean
• Stateful state maintained between method calls
• Stateless
• One client per session bean instance

19
EJB Message Driven Bean

• Message Driven Bean
• Used in conjunction with Java Messaging System
• Activated on JMS message arrival
• No state maintained between activations

session facade

20
Servlets

• Servlets
• Used for web applications
• Extend functionality of an HTTP server
• Replace CGIs
• Servlet support defined by specification
• Filters are part of the spec
• Consist of get and post methods for requests

21
History Applets

• Applets
• Not part of the J2EE framework
• Web-deliverable applications
• Run on client
• Problems
• Require correct JVM on client
• Difficult to write and change
• Presentation and logic combined

22
Servlets JSP

• Java Server Pages
• Interactive web pages
• ltjspinclude page/docs/footer.html/gt
• lth2gtltbeanwrite property"pageTitle
  name"swfForm"/gtlt/h2gt
• lt String tempUrl http//www.rpi.edu gt
• Extension of Servlet technology
• Similar to ASP
• Standard Tag Libraries available
• Struts
• MVC framework
• Industry standard
• Extensible
• Can define and implement tag libraries
• Used by numerous vendors, including ColdFusion MX

23
Servlets Filters

• Filters
• Transform HTTP requests and responses

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Servlets Filters

• Filter Example The Kiosk

25
Examples

• Example Applications
• The Kiosk Clones
• Web Forms
• RCS User Profile Manager
• Conference Site Management

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Example The Kiosk

• Departmental news service
• Role-based content management
• Proof of concept

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Example The Kiosk
client view
admin view
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Kiosk Clones
http//j2ee.rpi.edu/kiosk
http//www.va.rpi.edu
http//www.eng.rpi.edu/frame_news.html
29
Example Web Forms

• Process html pdf web forms
• Generate email while hiding recipient email
  addresses from web
• Attach files
• Save values in DB
• Skin switching
• Generated by admin tool or externally

30
Example Web Forms
31
Example Web Forms
Servlets JSP/XML/XSLT
Session Beans
EntityBeans

• Form Defs
• Form Values
• Attachments

Message Driven Beans
client view
admin view
mail.rpi.edu
32
Example RCS Profile Manager

• Billing information
• Passwords
• Web mail quota
• Disk usage
• Library passwords
• EZ-Snapshot usage
• General Info
• More to come

33
Example Conference Site

• Self registration
• To come
• Credit-card payment
• Integrated forums
• More user management
• Events scheduling
• News posting

34
Vendor Solutions

• Purchased Applications
• Many vendors build in the J2EE paradigm
• Can deploy on the same application server
• Example Jive Forums
• Servlet application
• http//www.jivesoftware.com
• http//jiveforums.rpi.edu8080/jive

35
Future Directions

• Current Future Projects
• Web Services
• Calendar Systems
• Directory
• File Services

36
Thank you

• References and Useful Links
• J2EE
• http//java.sun.com/j2ee/
• http//java.sun.com/j2ee/j2ee_guide.pdf
• JBoss
• http//www.jboss.org
• Development Tools
• http//jakarta.apache.org
• http//www.w3.org
• IBM Grid Computing
• http//www.javaworld.com/javaworld/jw-09-2002/jw-0
  906-grid_p.html
• Oracle Banner
• http//www.oracle.com/ip/deploy/ias/
• http//technet.oracle.com/oramag/webcolumns/2003/o
  pinion/otn_forms.html
• http//www.sct.com/Education/Products/Solutions/Es
  TechOracle.html
• Our J2EE presentations
• http//www.rpi.edu/dept/cct/public/j2ee/