JavaME (Java Platform, Micro Edition) is a Java runtime environment and a collection of Java APIs for resource-constrained devices such as PDAs, cell phones and other consumer appliances.
JavaME applications are often named as midlets.

A configuration defines a virtual machine and the minimum APIs that must be present. In defining the virtual machine,the configuration specifies the minimum amount of memory that must be present as well as the minimum processor type and speed.

CLDC (Connected Limited Device Configuration) is targeted at devices with very limited resources such as mobile phones.

Typical hardware requirements are: 16-bit CPU, a total of 160 KB memory available to the Java platform, as well as a limited connection to some kind of network.

Existing versions are CLDC 1.0 & CLDC 1.1.

A profile refers just to the APIs for a specific domain. A profile sits on top of a configuration.

For example, the MIDP (Mobile Information Device Profile), existing on mobile phones. Current versions are: MIDP 1.0, MIDP 2.0, MIDP 3.0.

Here is a list of mobile phones and what versions of CLDC/MIDP they provide.

A JAR file (or Java ARchive) is a ZIP file which stores compiled Java classes, resources and associated metadata that can constitute a program.

JAD files (Application Descriptor) describe the Java ME applications that are distributed as JAR files. (They contain information such as size, MIDP version, CLDC version...).

The Sun Java Wireless Toolkit (see here) include emulators.


Nokia download page: here. (Will need to register first).

Sony Ericsson download page: here - nice and easy to install.

Many other emulators from major phone producers are available.


There are also emulators running in applets, useful for online demonstrations. See Microemulator