J2ME - Java 2 Platform, Micro Edition

The Java 2 Platform, Micro Edition (J2ME) provides a robust, flexible environment for software applications running on consumer devices and a broad range of embedded devices. J2ME includes Java virtual machines and a set of standard Java APIs defined through the Java Community Process.

J2ME delivers the power and benefits of Java technology to consumer devices and embedded devices. J2ME includes flexible user interfaces, a robust security model, a broad range of built-in network protocols, and extensive support for networked and offline applications that can be downloaded dynamically. Applications based on J2ME specifications are written once for a wide range of devices, yet exploit each device's native capabilities.

The J2ME platform is deployed on millions of devices. In short, it is the platform of choice for today's consumer and embedded devices.

The Architecture: J2ME

The J2ME architecture comprises of a variety of configurations, profiles, and optional packages that implementers and developers can choose, and combine to construct a complete Java runtime environment that closely fit the requirements of a particular range of devices and a target market. Each combination is optimized for the memory, processing power, and I/O capabilities of a related category of devices. The result is a common Java platform that takes full advantage of each type of device to deliver a rich user experience.

Configurations: J2ME

Configurations comprise a virtual machine and a minimal set of class libraries. They provide the base functionality for a particular range of devices that share similar characteristics, such as network connectivity and memory footprint. Currently, there are two J2ME configurations: the Connected Limited Device Configuration (CLDC) and the Connected Device Configuration (CDC).

Profiles: J2ME

To provide a complete runtime environment for a specific device category a configuration must be combined with a profile, a set of higher-level APIs that further define the application life-cycle model, the user interface, and access to device-specific properties. A profile supports a narrower category of devices within the framework of a chosen configuration. A widely adopted example is to combine CLDC with the Mobile Information Device Profile (MIDP) to provide a complete Java application environment for cell phones and other devices with similar capabilities.

Optional Packages: J2ME

Adding various optional packages to a technology stack that includes either CLDC or CDC and an associated profile can extend the J2ME platform. Created to address specific application requirements, optional packages offer standard APIs for using both existing and emerging technologies such as database connectivity, wireless messaging, multimedia, Bluetooth, and web services. Because optional packages are modular, developers can avoid carrying the overhead of unnecessary functionality by including only the packages and applications they actually need