Next Generation Wireless Applications: Creating Mobile Applications in a Web 2.0 and Mobile 2.0 World, 2nd Edition

6.5 INTRODUCING J2EE – THE ‘DIRTY STUFF’ DONE FOR US!

Ideally, we want to be free to develop our mobile application software without having to develop software to take care of all the infrastructure issues we outlined in the last section. The ideal solution would be to use a software platform that already provides these ‘software infrastructure’ services for us. This is exactly what a J2EE (Java 2 Enterprise Edition) application server does, as shown in Figure 6.14.

The J2EE platform comprises of four software themes:

1. Java language support across a wide variety of underlying operating systems
2. Infrastructure services provision for enterprise applications
3. A programming model to enable infrastructure services to work
4. Set of software services to provide powerful interfacing capabilities to enterprise information service tier (e.g. databases, mail servers, etc.)

Our interest for the current discussion is especially with items two, three and four. For now, we are not interested in the Java programming paradigm. This is discussed later when we look at using Java to program applications directly on the devices (Java 2 Micro Edition – J2ME). For now, we will just take the underlying J2EE mechanisms for granted (e.g. Java support) and not be so concerned with how the programmer writes code. We are more interested in how J2EE enables us to build a mobile services platform, so the infrastructure services concept is more relevant to the current discussion.

Figure 6.15 J2EE programs are called ...