Java Data Objects

Introduction

Objects have successfully addressed all of the issues to make themselves the basis of a robust, large-scale and malleable development technology--except one. Persistence. In fact, any large scale technology with significant complexity in both the processing and data will hit the problem. Programming languages are not easily given automatic persistence, and database management systems are not very good at organising processing complexity.

Java has already had one success achieving persistent objects: Enterprise JavaBeans (EJB). The approach of EJB is that of making transactionally secure database entities appear to their clients as Java objects. There is another approach recently emerged from the Java Community Process--Java Data Objects (JDO). This is a different, complementary approach: making Java program objects automatically persistent. We also look at how JDO can work with EJB by offering a mechanism for bean-managed persistence.

Duration and Construction

The course lasts two days. It is based on a cycle of theory-language-practice-review, with approximately two cycles per day. One non-trivial, practical case-study is developed during the course.

Each day will start at 09.00 and finish at 16.30.

Intended Audience

Participants will be practising software engineers who already know and use Java. They may well have attended the Advanced Java course.

Aims

To understand the nature and difficulties of persistence
To understand the difficulties of the next generation of databases
To understand the comparative merits of EJB and JDO
To understand the JDO architecture
To understand and use the mechanisms--reachability, descriptors and byte-code enhancers--of JDO
To understand and practice the persisting of Java objects

Numbers

We recommend that there are no more than 10 participants, each working at his or her own machine.

Deliverables

Lectures
Facilitation of discussions
Direction, assistance and feedback on exercises
Proposed solutions to the exercises
Copies of lecture slides, plus explanatory text and summaries
Reference list of books and sources

Objects, databases and persistence
EJB's approach
The comparative merits of JDO and EJB
EJB bean-managed persistence using JDO
The JDO architecture
Local persistence
Enterprise persistence
XML descriptors
The JDO life-cycle
Persistence-by-reachability
Persistence-aware classes and JDOHelper
Transaction contexts and JDO
The bootstrap problem and JDOQL

Site Requirements

One PC with Java 1.4 (Forte, JBuilder or Cafe) and J2EE, per participant (including one for the lecturer), preferably networked and with a printer
Data projector with a real 1024 x 768 resolution, and suitable screen
White-board, preferably not doubling up as the projector's screen; blackboard and chalk are acceptable
Flip-chart and easel, with additional flip-chart paper

Contacting

Please contact Matrice by telephone on +44 7010 704705; by fax on +44 7010 704706; by emailing bookings@matrice.co.uk; or by visiting http://www.matrice.co.uk