The Basics of J2ME
Topics in this Chapter
- Java Editions
- Why J2ME?
- Java Virtual Machines
- Big Picture View of the Architecture
- Compatibility between Java Editions
- Putting all the Pieces Together
It all started with one version of Javanow known as Java 2 Standard Edition (J2SE)and the tagline "Write Once, Run Anywhere ™." The idea was to develop a language in which you would write your code once, and then it would run on any platform supporting a Java Virtual Machine.
Since its launch in 1995, the landscape has changed significantly. Java has extended its reach far beyond desktop machines. Two years after the introduction of Java, a new edition was released, Java 2 Enterprise Edition, providing support for large-scale, enterprise-wide applications. The most recent addition to the family is the Micro Edition, targeting "information appliances," ranging from Internet-enabled TV set-top boxes to cellular phones.
Let's begin with a quick summary of the Java platforms currently available:
Standard Edition (J2SE): Designed to run on desktop and workstations computers.
Enterprise Edition (J2EE): With built-in support for Servlets, JSP, and XML, this edition is aimed at server-based applications.
Micro Edition (J2ME): Designed for devices with limited memory, display and processing power.
Figure 11 shows various Java editions.
In December of 1998, Sun introduced the name "Java 2" (J2) to coincide with the release of Java 1.2. This new naming convention applies to all editions of Java, Standard Edition (J2SE), Enterprise Edition (J2EE), and Micro Edition (J2ME).
Figure 11 The various Java editions