Wireless Java

Chapter 3. The Mobile InformationDevice Profile (MIDP)

The Mobile Information Device Profile (MIDP) is built on top of the CLDC, and defines an open application development environment for what Sun calls Mobile Information Devices (MIDs). In simpler terms, MIDP is the J2ME profile that is used for wireless devices, such as mobile phones and pagers. This chapter expands on the previous chapter by introducing some of the fundamental concepts of MIDP and offering programming guidelines that are used throughout the remainder of this book.

As we mentioned in Chapter 1, the MIDP is governed by the Java Community Process. The MIDP is JSR 37, which is part of the Java Community Process. Like the CLDC, the MIDP is an ever-changing standard that actively solicits input from corporations and the general programming community. You can find more information on the MIDP at the following URL: http://java.sun.com/products/midp.

Mobile Information Devices

Again, let’s start off with some specifics. The MIDP standard defines a MID as a device with the following minimum characteristics:

Display

A screen size of at least 96 x 54 pixels with at least a 1-bit display depth

Input

A one-handed keyboard, two-handed keyboard, or touch screen

Memory

32 KB of volatile memory for the Java runtime (heap); 128 KB of non-volatile memory for the MIDP components; and 8 KB of non-volatile memory for application-created persistent data

Networking

A two-way intermittent connection, usually wireless, with limited ...