intro to j2ee

Introduction to J2EE

1

Introduction to Java 2 Enterprise Edition

Presented by

Communication & Collaboration TechnologiesDivision of the Chief Information Officer

Rensselaer Polytechnic Institute

Welcome!


2

Main Topics

• Introduction– The Goal– The Problem– The Solution

• What is J2EE?

• The J2EE Framework

• Case Studies / Examples


3

Introduction

“Enterprises today need to extend their reach, reduce their costs, and lower their response times”

– Simplified Guide to the Java 2 Platform, Enterprise Edition, Sun Microsystems, Inc.


4

Introduction

IT must provide:

• High quality services– Highly Available– Secure– Scalable

• Powerful services– Useful– Flexible– Extensible

• Affordable


5

The Problem

• produce • purchase• support• maintain• replace

Complex software is expensive to:

Difficult Tasks!


6

?

The Problem

Why not delegate components to different departments?

Departmental solutions are:• Limited in scope

– Difficult to be aware of enterprise- wide requirements and initiatives

• Difficult to leverage– Diverse interoperabilty standards


7

• Cost and complexity– Solution: Leverage reusable software components

• Limited scope and impact– Solution: Provide interfaces that enable enterprise-wide

application development

• Diverse standards– Solution: Utilize existing standards and software components

• Strength: Leveraged departmental core compentencies– Strongly defined roles and software interfaces

allow maximum collaboration

The Solution


8

What is J2EE?

What is Java 2 Enterprise Edition?

"The Java 2 platform, Enterprise Edition reduces the cost and complexity of developing ... multi-tier services, resulting in services that can be rapidly deployed and easily enhanced“

– Simplified Guide to the Java 2 Platform, Enterprise Edition, Sun Microsystems, Inc.


9

What is J2EE?

• Enabling technology• Standards based application model• A common architecture that provides

key common functionality:– Security– Session Management– Scalability

J2EE Provides:


10

What is J2EE?

• Applications architecture• Partitioning of application logic• Improves maintainability• Simplifies software upgrades and

management

What does "multi-tier" mean?


11

What is J2EE?

• Enables increased aggregate functionality• Reduces component maintenance cost• Separation of workload to improve

scalability and reliability• Strong separation prevents

vendor lock-in

What does "multi-tier" mean?


12

Some History

Two tier application ("thin client")

• Easy to upgrade client• Expensive to scale and to add functionality

*Business Logic

serverclient

*


13

Some History

Two tier application ("client/server")

• Strong scalability• Poor upgradability and difficult management

serverclient


14

Today

Three tier application

• Thin clients make easy upgrades• Centralized application server management is

easier to manage• Model allows for horizontal scalability

client app server server


15

Today

Three tier application

• Thin clients make easy upgrades• Centralized application server management is

easier to manage• Model allows for horizontal scalability

client app server server


16

Today


17

N-tier application

• View application server as a data store• Leverage data abstraction

Today


18

N-Tier Application


19

N-Tier Application

Banner

LDAP


20

N-Tier Application


21

N-Tier Application


22

N-Tier Application


23

N-Tier Complexity


24

Business Logic


25

Business Logic

data

PROCESS

OUTPUT

INPUT

data


26

N-Tier Complexity


27

N-Tier Complexity


28

N-Tier Complexity


29

N-Tier Complexity


30

N-Tier Complexity


31

N-Tier Complexity


32

ServletsJSP/XML/XSLT

SessionBeans

EntityBeans

J2EE


33

J2EE


SessionBeans

EntityBeans


34

Example: The Kiosk


35

Example: The Kiosk


SessionBeans

EntityBeans

article

category

get articleclient view

admin view

restore

utility


36

Clones

http://j2ee.rpi.edu/helpdesk http://j2ee.rpi.edu/kiosk

http://www.va.rpi.edu

http://www.eng.rpi.edu/frame_news.html


37

The J2EE Framework

Java Technologies

ExternalApplication

intro to j2ee

Documents