J2EE

Java2 Enterprise Edition

by

Damian Borth

Contents

• Introduction

• Architectures styles

• Components

• Scenarios

• Roles

• Processing a HTTP request

Java2 Enterprise Edition

• Java Development Kit (JDK)– Compiler– Debugger– JavaDoc

• Splitting of the one JDK– J2ME– J2SE– J2EE

Java2 Enterprise Edition

• J2EE– distributed platform– design, development,

assembly, deploy– component oriented Enterprise

Application

• Ontop of the J2SE

Java2 Enterprise Edition

• Include– J2EE Platform specification– J2EE Application Model– J2EE Compatibility Test Suite

J2EE Architecture

• N-Tier architecture– Frontend Tier

• presentation• input validation

– Middle Tier• business logic

– EIS Tier• RDBMS• Directory

J2EE Architecture

J2EE Component

• Web Container– JSP

• for dynamic web pages (document oriented)

– Servlets• point of entry for processing HTTP request

(programming oriented)

J2EE Component

• EJB Container– EJB are components, which provide services

via standard interfaces– Benefits

• Distribution management

• Persistence management

• Transaction management

• Security management

J2EE Component

• EJB Container– Session Beans

• provides functionality / service

– Entity Beans• representation of business data

– Message driver Beans• responsible for receiving messages via JMS

Defined scenarios

• Multitier Web Client Scenario

• Simple Web Client Scenario

• EJB Application Client Scenario

• Business-to-Business Scenario

Multitier Web Client Scenario

Simple Web Client Scenario

EJB Application Client Scen.

Business-to-Business Scenario

Defined Roles

• J2EE specification defines roles

• Six different roles– J2EE Tool provider– Application Component Provider– Application Assembler– Deployer– System Administrator– Tool Provider

Defined Roles

Processing a HTTP request

• Using a Model-View-Controller pattern

• Example:– Read data from database– Form with input boxes– POST method

Processing a HTTP request

Questions?