Programming Wireless Devices with the Java2 Platform

2.1 Java 2 Platform

Recognizing that one size does not fit all, Sun Microsystems has grouped Java technologies into three editions, each aimed at a specific area of today's vast computing industry:

• Java 2 Platform, Enterprise Edition (J2EE™) for enterprises needing to serve their customers, suppliers, and employees with scalable server solutions.

• Java 2 Platform, Standard Edition (J2SE™) for the familiar and well-established desktop computer market.

• Java 2 Platform, Micro Edition (J2ME™) for the combined needs of:

  • consumer and embedded device manufacturers who build a diversity of information devices,

  • service providers who wish to deliver content to their customers over those devices, and

  • content creators who want to make compelling content for small, resource-constrained devices.

Each Java platform edition defines a set of technologies that can be used with a particular product:

• Java Virtual Machines that fit inside a wide range of computing devices,

• libraries and APIs specialized for each kind of computing device, and

• tools for deployment and device configuration.

Figure 2.1 illustrates the Java 2 Platform editions and their target markets, starting from the high-end platforms on the left and moving towards low-end platforms on the right. Basically, five target markets or broad device categories are identified. Servers and enterprise computers are supported by Java 2 Enterprise Edition, and desktop and personal computers by Java 2 Standard Edition. Java 2 Micro Edition is divided broadly into two categories that focus on "high-end" and "low-end" consumer devices. Java 2 Micro Edition is discussed in more detail later in this chapter. Finally, the Java Card™ standard focuses on the smart card market.