What Does CLDC Refer To? CDC? MIDP?
Within Java development for mobile devices, there are several terms and acronyms developers should be familiar with. They generally refer to the bundles in which Java Micro Edition technology is delivered in client devices. Going from the most broad to the most specific, they are configurations, profiles and optional packages, and include support for certain technologies. For instance, configurations provide the most basic set of features, profiles add support for more features, and so on. Some key acronyms include:
- CLDC - Connected Limited Device Configuration
The CLDC is the most basic set of APIs and a virtual machine for resource-constrained devices like mobile handsets. Versions 1.0 and 1.1 of the CLDC are in wide use, and 1.1 is backwards compatible with 1.0.
- CDC - Connected Device Profile
The CDC is another Java ME configuration designed for resource-constrained devices such as consumer electronics and high-end PDAs. The CDC contains support for more features than the CLDC, and for more info on the differences, see this article. Far fewer mobile devices support the CDC than the CLDC.
- MIDP - Mobile Information Device Profile
MIDP is the Java ME profile most widely used in mobile phones, and adds a number of features on top of the CLDC. Handsets supporting only MIDP 1.0 remain in wide circulation, while MIDP 2.0, which is backwards compatible with and offers additional features on top of 1.0, is the current standard. MIDP 3.0 is currently being developed. - JSR - Java Specification Request JSRs are the specs for the Java platform, as defined by the Java Community Process. For instance, CLDC 1.1 is also known as JSR 139. Most often, within the scope of mobile devices and development, JSRs refer to optional packages and APIs that device manufacturers support to offer extended functionality to Java applications. For instance, a common one is JSR 82, which lets Java applications access Bluetooth, or JSR 135, the Mobile Media API, which lets Java apps play and record sounds and video and capture images. Sun has a diagram showing the relevant Java ME JSRs, with links to more information about each one.
Sun also maintains a database of Java ME devices that details which configurations, profiles and JSRs each supports.