J2ME technologies are based on configurations and profiles. A configuration defines the minimum set of class libraries available for a range of devices. A profile defines the set of APIs available for a particular family of devices. For example, the profile for the cell phone vertical market is separate from the
profile for the personal organizer vertical market, but both profiles work with the same configuration. See also the CDC and CLDC product pages.
J2ME Connected Limited Device Configuration (CLDC)
The J2ME Connected Limited Device Configuration (CLDC) specification consists of the K virtual machine and a core set of class libraries appropriate for use within an industry-defined profile. This configuration is intended for small wireless devices with simplified user interfaces, minimum memory budgets starting at about 128 kilobytes, and intermittent network connections with lower bandwidth.
The K virutal machine is a runtime implementation of the Java virtual machine. It is an extremely lean runtime for use in devices with a small memory footprint such as cell phones, two-way pagers, and personal digital assistants (PDAs). The K in K virtual machine stands for kilobyte to indicate this virtual machine works with a total memory of a few hundred kilobytes at most and sometimes fewer than 128 kilobytes.
J2ME Connected Device Configuration (CDC)
The J2ME Connected Device Configuration (CDC) specification is based on the classic Java virtual machine specification, which defines a full-featured runtime environment that includes all the functionality of a runtime residing on a desktop system. This configuration is intended for larger wireless devices with at least a few megabytes of available memory.
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