Hardware and Software Environment

The target application server will be JBoss 3.0.0, integrated with the Jetty servlet engine. Management is keen to minimize licensing costs, especially as the application may be deployed on a number of sites. The application may need to be ported to another application server in the future, so the design must not be dependent on JBoss. Should such porting be required, a small budget will be allocated for any code changes required and for testing on the new platform. If possible, the application should be verifiable as J2EE-compliant to reassure management that portability is achievable.

The X Center does not presently have its own web- facing hardware. Appropriate hardware will need to be purchased based on performance analysis; management is keen to minimize cost by maximizing performance per cost of hardware.

The application should support clustering if this becomes necessary as demand increases , but management expects that the performance figures described can be exceeded on a single server. All machines in any server cluster would be within the same local network.

The database will be Oracle 8.1.7i, as the X Center already has an Oracle license and Oracle expertise in-house. There is no likelihood of migrating to another database in the foreseeable future. The Oracle database already runs on a Sun server, and this will not change, regardless of the chosen hardware for the web server. The database server and application server(s) will run on the same local network, so rapid connectivity can be assumed.

There are no other constraints regarding technology to be used. Management have made a strategic decision to adopt J2EE because they believe it offers the best chance of successful integration with the legacy booking systems at the other venues with the X Group, but have no preconceptions on how J2EE should be used. Whether to use technologies such as EJB, JSP, and XSLT is a technical decision. As the project will involve building a team, no constraints regarding existing J2EE expertise (such as "strong servlet experience, no EJB experience") need be considered .

A number of the X Center's staff have HTML skills, but are non-programmers. Therefore it is important that HTML content and site presentation can be controlled, as far as possible, without the need for more than a superficial understanding of J2EE technologies.

Summary

In this chapter we've seen the requirements for the sample application. This is the commonest type of J2EE application – a web application using a relational database.

The discussion in the rest of the book will use the process of implementing this application to illustrate the J2EE design and implementation concepts discussed.

In the next chapter we'll take a closer look at options for J2EE architecture, and define a high-level architecture for the sample application.

In Chapter 7 to Chapter 9 we'll look at data access options for use in J2EE applications, and how we can efficiently implement the ticketing application's data access requirements.

In Chapter 11 we'll look at how a generic application infrastructure can be used to solve many common problems, and how it simplifies application-specific code.

In Chapter 12 and Chapter 13 we'll look at implementing web interfaces in J2EE applications, using the reservation use case from the sample application to illustrate how to use the MVC architectural pattern.

In Chapter 14 we'll look at J2EE application deployment, showing how to package the sample application and deploy it on JBoss 3.0.0.

In Chapter 15 we'll look at meeting the performance targets identified above.