Connected Limited Device Configuration (CLDC) defines a set of classes that together constitute the Generic Connection Framework (GCF). The GCF abstracts the concepts of input/output and networking into simple classes. It basically provides the same functionality as the java.io and java.net with some restrictions. CLDC does not provide functionality for any specific network protocols. Such implementations are left to Mobile Information Device Profile (MIDP), which only mandates support for HTTP (Hyper Text Transfer Protocol) 1.1 protocol.

• Learn how to use the generic connection framework to make wireless connections
• Brief introduction to the generic connection framework and HttpConnection from Sun
• Detailed description on how to make MIDlets communicate with servlets over HTTP from Sun
• Advanced tutorial on how to access sockets and RMI from MIDlets using servlets as a middleman architecture from Sun - includes two good examples.

Smart Ticket 1.2 is a sample application from Sun. It is a good illustration of how a J2ME client can communicate with a J2EE server to provide a wireless to enterprise server solution. This is also a good example of the Model View Controller (MVC) architecture. The guidelines discuss why MVC benefits outweigh the cost of increased code size.

• Guidelines for designing wireless clients
• Guidelines illustrated by the Smart Ticket sample application