What Is J2ME?
Since 1995, Java has grown into a complete and mature object-oriented development platform that allows easy and fast applications development for a great many hardware and software platforms, thereby significantly lowering cost of application development and maintenance.
In 1999, Sun divided Java into three separate editions. Java 2, Standard Edition (J2SE) is intended for use on common personal computers. Java 2, Enterprise Edition (J2EE) is designed for use on servers. Java 2, Micro Edition (J2ME) is designed for small devices with a limited processor power and small memory size. Mobile phones, personal digital assistants (PDAs), consumer electronics, and embedded devices are common examples of J2ME capable devices.
To support a wide variety of device types, J2ME technology adopts a modular and scalable architecture. It has two primary kinds of componentsconfigurations and profiles. J2ME configuration defines the minimum set of Java virtual machine features and Java class libraries available for a particular category of devices. A configuration typically represents a group of devices with similar processing power and amounts of available memory. A profile is a specification that defines sets of application programming interfaces (APIs) and features and utilizes the underlying configuration to provide a complete run-time environment for a specific kind of device.
Today's mobile phones and entry-level PDAs use Mobile Information Device Profile (MIDP) combined with Connected Limited Device Configuration (CLDC) as the J2ME run-time environment. More information on J2ME technology is available at java.sun.com/j2me.