The expert group for JSR 139, Connected Limited Device Configuration 1.1, has published the final release of its specification. This JSR This specification defines a revised version of the J2ME Connected, Limited Device Configuration (CLDC).
The Final Release of the specification is available from the Java Community Process Web site at:
This specification will define a revised version of the J2ME Connected, Limited Device Configuration (CLDC).
J2ME CLDC defines a standard platform for small, resource-constrained, connected devices characterized as follows:
- At least 160 kilobytes of total memory available for the Java platform. - Processor speed starting from 8-32 MHz. - 16/32 bit processor. - Limited power, usually battery operation. - Connectivity to some type of network, with possibly limited (9600 bps or less) bandwidth. - High-volume manufacturing (usually millions of units). - User interfaces with varying degrees of sophistication down to and including none.
The actual device characteristics and memory footprint requirements for the next-generation CLDC will be determined by the Expert Group. Cell phones, two-way pagers, personal digital assistants, and small appliances are some, but not all, of the devices that may be supported by this configuration specification.
The general goal of the proposed new specification is to make CLDC compliant with the Java Language and Virtual Machine Specifications by possibly reintroducing features such as floating point support and improved error handling capabilities (especially class loading errors and verification errors).
In contrast, the CLDC libraries will not be extended significantly in order to meet the strict memory footprint requirement demanded by CLDC target devices. The expert group will investigate the possibility of adding a minimal security manager and/or class unloading support. Additional libraries are more appropriately added to profiles defined on top of CLDC, so that CLDC can stay small, simple and broadly applicable.
Devices that require significantly more complete Java libraries should use the J2ME Connected Device Configuration (CDC) instead.
Additional goals for the proposed specification include:
- Backward compatibility with CLDC 1.0. - Continued focus on small, resource-constrained, connected devices. - Continued focus on generality (instead of focusing on any particular device category). - Continued focus on maintaining the tight footprint objectives to limit the API growth. - Utilize experiences learned from CLDC 1.0 deployments to fine tune the specification.