Java 2 – Enterprise Edition Kevin J. LaFata April 21, 2003 UM – St. Louis.

Java 2 – Enterprise Edition

Kevin J. LaFata

April 21, 2003

UM – St. Louis

Overview

J2EE Intro Key Concepts JSP and Servlets XML Building and Deployment EJB More info and job market

What makes up J2EE

Enterprise Java Beans (EJB)

JDBC Java Messaging

Service Servlets JSP

JNDI Java Mail XML SOAP JAAS JTA and others…

J2EE as a Specification

Specifications Interfaces Libraries Implementations

Key Concepts

XML Deployment When & what to use OO Design Syntax – less important

JSP

JSP Directives HTML Embedded Code Tag Libraries/Custom Tags Sessions

JSP Translation

JSP Translated into a servlet Uses HTTPServlet package Servlet compiled and executed Done by Tomcat

Servlets

Special interface Uses response and request objects Run by a server such as Tomcat

JSP Example

Servlet Example

XML Importance

Used everywhere in Java Data standardization Configuration Files Deployment File

XML Basics

Special Header Like HTML Must be well formed All tags must be closed Tags can have data, attributes, other

tags DTDs

XML Example

XSLT

Translates XML to something Usually HTML Selection language Looping, conditionals

ANT

Like a Makefile Many Java specifics Defined using XML Build targets and tasks

ANT Example

Deployment

Jar files – Libraries War files – Web applications Ear files – EJB Deployments Manifests and information along with

class files and resources XML used to define deployment

descriptors

Enterprise Java Beans

Specifications Containers Adds scalability, thread safety,

transactions Security

Bean Types

Stateless Session Beans Stateful Session Beans Entity Beans

Session Beans

Perform actions Business rules and logic Can maintain session Pooled by server

Entity Beans

Represent data or objects Usually persistent Underlying data storage Storage can be handled by bean or by

server

Transactions

Atomic – all or nothing Consistency – data is valid Isolation – data locking Durability – data stays permanent

Implementations

JBoss BEA Weblogic IBM WebSphere Oracle Application Server Jakarta Tomcat

Learn by trying

Tomcat JBoss MySQL Oracle (Development)

For more information

100’s of books java.sun.com

Job Market

A.G. Edwards Anheuser Busch Enterprise Rent-A-Car

OO Design Important Side Projects Additional Skills