J2ME in a Nutshell

Chapter 7. The Connected Device Configuration and Its Profiles

The Connected Limited Device Configuration (CLDC) and the Mobile Information Device Profile (MIDP) bring a usable, if restricted, Java programming capability to a very large number of small devices. There is a wide gulf between the cell phones and small PDAs that the CLDC profiles address and the desktop world of J2SE, and between these two extremes lie a range of other devices. Among these are consumer electronic devices such as set-top boxes, two-way pagers, and larger PDAs that, while not needing to support the complete J2SE environment, are nevertheless not well served by CLDC and MIDP and have the resources to host a more capable Java platform. The Connected Device Configuration (CDC) is the J2ME configuration that is aimed at this class of device. This chapter provides an overview of CDC and the current state set of profiles that are defined for it, many of which are, as yet, not fully specified.

The CDC

The CDC is targeted at devices that have a minimum of 2 MB of memory available to be used by the Java VM and its class libraries. As with CLDC, most devices probably have the VM and the core class libraries in ROM or Flash memory, but they also require RAM for application classes (unless the application is embedded and hence also included in the ROM) and the Java heap.

CDC devices typically have a 32-bit processor and a network connection, which may be intermittent or permanent, often directly to the Internet or ...