In computing, the Java Platform, Micro Edition or Java ME (still commonly referred to by its previous name: Java 2 Platform, Micro Edition or J2ME) is a specification of a subset of the Java platform aimed at providing a certified collection of Java APIs for the development of software for tiny, small and resource-constrained devices based on microcontrollers such as ARM7, ARM9, AVR32, ... Target devices are from many industries: Home appliances, Security, Defense, Automotive, Industrial, Handsets, Industrial Control, Multimedia, Communication, ... cell phones , PDAs and set-top boxes are some well known samples.

Java ME was designed by Sun Microsystems and is a replacement for a similar technology, PersonalJava. Originally developed under the Java Community Process as JSR 68, the different flavors of Java ME have evolved in separate JSRs. Sun provides a reference implementation of the specification, but has tended not to provide free binary implementations of its Java ME runtime environment for mobile devices, rather relying on third parties to provide their own.

As of 22 December 2006, the Java ME source code is licensed under the GNU General Public License, and is released under the project name phoneME.

Usage

Java ME has become a popular option for creating games for cell phones, as they can be emulated on a PC during the development stage and easily uploaded to phones. This contrasts with the difficulty of developing, testing, and loading games for other special gaming platforms such as those made by Nintendo, Sony, Microsoft, and others, as expensive system-specific hardware and kits are required.

Java ME devices implement a profile. The most common of these are the Mobile Information Device Profile aimed at mobile devices, such as cell phones, and the Personal Profile aimed at consumer products and embedded devices like Set-top boxes and PDAs.

Profiles are subsets of configurations, of which there are currently two: the Connected Limited Device Configuration and the Connected Device Configuration.

Connected Limited Device Configuration

The Connected Limited Device Configuration (CLDC) contains a strict subset of the Java-class libraries, and is the minimal amount needed for a Java virtual machine to operate. CLDC is basically used to classify myriad devices into a fixed configuration.

A configuration provides the most basic set of libraries and virtual-machine features that must be present in each implementation of a J2ME environment. When coupled with one or more profiles, the Connected Limited Device Configuration gives developers a solid Java platform for creating applications for consumer and embedded devices.

Mobile Information Device Profile

Designed for cell phones, the Mobile Information Device Profile includes a GUI API, and MIDP 2.0 includes a basic 2D gaming API. Applications written for this profile are called MIDlets. Almost all new cell phones come with a MIDP implementation, and it is now the de facto standard for downloadable cell phone games. However, many cellphones can run only those MIDlets that have been approved by the carrier, especially in North AmericaFact: date=December 2007.