The Client Tier

by Ray Ortigas

From a developer's point of view, a J2EE application can support many types of clients. J2EE clients can run on laptops, desktops, palmtops, and cell phones. They can connect from within an enterprise's intranet or across the World Wide Web, through a wired network or a wireless network or a combination of both. They can range from something thin, browser-based and largely server-dependent to something rich, programmable, and largely self-sufficient.

From a user's point of view, the client is the application. It must be useful, usable, and responsive. Because the user places high expectations on the client, you must choose your client strategy carefully, making sure to consider both technical forces (such as the network) and non-technical forces (such as the nature of the application). This chapter presents guidelines for designing and implementing J2EE clients amidst these competing forces.

This chapter cites examples from the Java Pet Store sample application, an online outlet for selling pets, and the Java Smart Ticket sample application, an e-commerce movie ticket service. The code for these sample applications is available on the Java BluePrints Web site. See "References and Resources" on page 73 for more information.