Java 2 Micro Edition (J2ME)

Java was created by Sun Microsystems Ltd. in 1995. Although the Internet had already begun to emerge by that time, existing programming languages couldn’t effectively work with it. Java changed this by enabling the development of web client programs capable of downloading and running applets. Java brought several significant advantages, which contributed to its rapid success and widespread adoption.

This success was followed by the development of Java Enterprise Edition (J2EE) for server-side programming. Later, Java 2 Micro Edition (J2ME) was introduced to support mobile device programming. J2ME is specifically designed for small devices, known as J2ME devices, such as smartphones, interactive television set-top boxes, pagers, PDAs, and other wireless devices. It includes various virtual machines and application programming interfaces (APIs).

Design Objectives of J2ME

One of the primary design goals of J2ME was to ensure portability across multiple mobile platforms. This allows the same application to run on different devices, even if they are made by different manufacturers and use different operating systems. Mobile devices typically have significant limitations compared to traditional computers, and J2ME was designed with these constraints in mind.

Key Differences Between Conventional Computers and J2ME Devices

Some of the major differences between traditional computers and J2ME devices include:

• Limited processing power
• Limited system memory
• Limited storage capacity
• Small display size
• Low battery power
• Limited Internet connectivity

J2ME Architecture

J2ME includes a compact version of the Java Virtual Machine (JVM), known as the K Virtual Machine (KVM). This version of the JVM is optimized to run small Java programs called MIDlets on mobile devices. This innovation helped extend Java’s famous “Write Once, Run Anywhere” principle to mobile devices.

Key Features of J2ME Applications

J2ME applications are lightweight and offer a variety of useful features, including:

• Opening UDP connections between two devices
• Establishing HTTP connections with servers
• Making socket connections
• Scanning bar codes

Popular Applications of J2ME

J2ME has been widely used in several domains, including:

• Automotive systems
• Set-top boxes and interactive televisions
• Network-connected consumer devices with graphic user interfaces (GUIs)

By providing a powerful yet lightweight platform for mobile devices, J2ME has enabled the development of a broad range of applications that have greatly influenced mobile computing.