J2ME

Java APIs targeting embedded consumer products such as PDAs, cell phones and other consumer appliances.

J2ME has become a popular option for creating cell-phone games as they can be emulated on a PC during the development stage and automatically uploaded to the cell-phone. This contrasts with the difficulty of developing, testing, loading games for other special gaming platforms such as those made by Nintendo, Sony and others as special and expensive hardware and kits are required. Some cell-phone makers also extend the J2ME platform to provide more robust effects such as 3D graphics and audio which lacks a specification in the current J2ME APIs.

Configurations and Profiles

J2ME devices implement a Profile, the most common of these is the Mobile Information Device Profile, aimed at mobile devices, such as cell phones and the Personal Profile aimed at consumer products and embedded device like Set-top_boxes and PDAs. A Profile is a superset of a Configuration, off which there are currently two, Connected Limited Device Configuration and Connected Device Configuration.

Connected Limited Device Configuration

The CLDC contains a strict subset of the Java class libraries, and is the minimal needed for a JVM to operate.

Mobile Information Device Profile

Designed for cell phones, it boasts a LCD oriented GUI API, with MIDP 2.0 including a basic 2D gaming API. Applications written for this 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.

Information Module Profile

The Information Module Profile (IMP) is a Java 2 Platform, Micro Edition (J2ME) profile for embedded, "headless" devices such as vending machines, industrial embedded applications, security systems, and similar devices with either simple or no display and with some limited network connectivity.

Originally introduced by Siemens Mobile and Nokia as JSR-195, IMP 1.0 is a strict subset of MIDP 1.0 except that it doesn't include user interface (UI) application programming interfaces (API) - in other words, it doesn't include support for the Java package javax.microedition.lcdui. JSR-228, also known as IMP-NG, is IMP's next generation that is based on MIDP 2.0, leveraging MIDP 2.0's new security and networking types and APIs, and other APIs such as PushRegistry and platformRequest(); but again it doesn't include UI APIs, nor the game API.

IMP applications are called IMlets, but in reality they are MIDlets; they subclass MIDlet, and follow the same packaging, deployment, security and life-cycle as MIDlets.

Connected Device Configuration

The CDC is a larger subset J2SE, containing almost all the non-GUI related libraries.

Foundation Profile

A headless version of J2SE.

Personal Basis Profile

Extends the foundation profile to include lightweight GUI support.

Personal Profile

Extension to Personal Basis Profile including complete AWT and Applet.