UNIT III - Chapter 1 - An Introduction to MIDP 2.0

When MIDP 1.0 specification was launched on 1st September, 2000 the mobile phone environment was at the crossroads. The wireless communication revolution and the computing revolution had finally reached a place where they had to merge. The MIDP 1.0 specification was built keeping that in mind. At that time nobody knew how mobile devices will be used as information devices. Mobile gaming which is a hot sector these days was an alien term in those days. What we had were very simple games like ‘Snake’. In that scenario, publishing MIDP 1.0 specification was a remarkable feet.

Many companies started software development for mobiles after the launch of MIDP 1.0. But then they realized that MIDP 1.0 although a technical marvel lacked certain aspects of a good software development platform. To rectify this MIDP 2.0 specification was finally on 5th November, 2002.

MIDP 2.0 (JSR 118) was launched to increase the programmatically of mobile devices in the J2ME platform. MIDP 2.0 contains many useful APIs that lacked in the MIDP 1.0 specification.  Some of the new and useful features are:

  1. New user interface elements
  2. Gaming API
  3. Ability to make secure connections
  4. APIs for generating sounds

Thus we see that MIDP 2.0 offers several advantages over MIDP 1.0. Also MIDP 2.0 is backward compatible with MIDP 1.0. Thus if you have created some applications in MIDP 1.0 they will run perfectly fine in MIDP 2.0. Now in fact we are seeing an explosion of devices that can run MIDP 2.0.

We know by now that MIDP 2.0 is a better programming environment then MIDP 1.0. It contains more APIs then MIDP 1.0. Now we will briefly discuss the various APIs contained in MIDP 2.0. MIDP 2.0 specification defines the following APIs:

Core Packages:

ü  java.lang

ü  java.util

Application Lifecycle Package:

ü  javax.microedition.midlet

Networking Package:

ü  javax.microedition.io

User Interface Package:

ü  javax.microedition.lcdui

ü  javax.microedition.lcdui.game

Application Lifecycle Package:

ü  javax.microedition.rms

Sound and Tone Media Package:

ü  javax.microedition.media

ü  javax.microedition.media.control

Public Key Package:

ü  javax.microedition.pki


Many of the packages listed above contain the same APIs contained in MIDP 1.0. Thus keeping economy in mind I will be discussing only the classes or interface which have been changed or are in new in MIDP 2.0 or which I have felt are important for an understanding of MIDP platform in general. Nearly all the changes contained in MIDP 2.0 have been discussed in the text below. Although there are certain APIs which were left out as they were not deemed to be very important. For a full idea of MIDP 2.0 please read the MIDP 1.0 APIs also.