CLDC platform and utilities APIs

The CLDC platform and utilities APIs provide core language functionality for your applications. The packages are:

CLDC 1.1 core packages
J2ME web server packages
RIM packages that are extensions to CLDC and J2ME

CLDC 1.1 core packages

These packages are part of JSR 139, Connected Limited Device Configuration version 1.1. These packages provide the core set of APIs for developing applications on resource-constrained wireless devices, such as BlackBerry smartphones.

java.lang provides the core Java classes
java.lang.ref provides support for weak references (references that do not protect objects from garbage collection)
java.util provides the standard collection classes (Hashtable, Stack, and Vector) and date/time support

J2ME Web Services packages

These packages are part of JSR 172, the J2ME Web Services Specification. These packages provide basic support for Java ME devices, such as a BlackBerry smartphone, to act as a web service client using standard programming interfaces.

java.rmi provides the core Remote Method Invocation classes
javax.microedition.xml.rpc provides JAX-RPC support
javax.xml.namespace provides namespace support
javax.xml.parsers provides support for processing XML documents by using SAX (Simple API for XML) event-based XML processing
javax.xml.rpc provides JAX-RPC support on the web service client
org.xml.sax provides core SAX support
org.xml.sax.helpers provides helper classes for SAX support

RIM extension packages

RIM provides APIs that complement Java Community Process APIs.

For example, you can use RIM provided collection classes, such as BigVector or UnsortedReadableList, instead of the standard Vector class.

In some cases, RIM provides classes that exist in Java SE but are not provided (or only partially provided) in standard Java ME. For example:

net.rim.device.api.xml.parsers supplements javax.xml.parsers by adding DocumentBuilder and DocumentBuilderFactory, classes available in Java SE but not in standard Java ME
net.rim.device.api.util.Arrays provides much of the functionality of Java SE's Arrays class, which is not available in standard Java ME
net.rim.device.api.util.MathUtilities contains methods that are available in Java SE's java.lang.Math class, but not in standard Java ME, including inverse trigonometric methods
net.rim.device.api.xml provides constants for use in processing WBXML, which is a binary form of XML suitable for use in wireless applications
net.rim.device.api.xml.jaxp package provides support for XML processing and supplements org.xml.sax by adding extensions to the standard helper classes

The RIM-provided packages in the CLDC Platform and Utilities category are:

Web-service and XML-related packages: net.rim.device.api.xml, net.rim.device.api.xml.jaxp, and net.rim.device.api.xml.parsers
Collections-related packages: net.rim.device.api.collection, net.rim.device.api.collection.util, and net.rim.device.api.util
Math and other utilities: net.rim.device.api.math and net.rim.device.api.util

More information about the CLDC category and utilities

J2ME Web Services (Sun white paper)