Next Generation Wireless Applications: Creating Mobile Applications in a Web 2.0 and Mobile 2.0 World, 2nd Edition

11.10 WHAT DOES MIDP 2.0 OFFER?

At the time of writing this second edition, MIDP 2.0 is the widest supported J2ME profile for mobile devices, although MIDP 3.0 is nearly ready. We shall talk about MIDP 3.0 in a moment, but first let's look at what using MIDP 2.0 technology can do for us. Where possible, in keeping with the ethos of this chapter, we shall compare and contrast the available capabilities with other means of developing mobile applications, so as to keep our discussion relevant to the theme of mobile service delivery, not J2ME per se, as there are plenty of books in this topic²⁹.

The MIDP 2.0 specification is based initially on the MIDP 1.0 specification and provides backward compatibility with MIDP 1.0 to the extent that MIDlets written for MIDP 1.0 can execute in MIDP 2.0 environments. The momentum behind MIDP had been gathering in the marketplace, so backwards compatibility was an important consideration. This is a problem particularly pertinent to the mobile devices market because upgrades in the field are very unusual, unlike the desktop PC environment, where they are the norm.

As already discussed, the MIDP is designed to operate on top of the CLDC. While the MIDP 2.0 specification was designed assuming only CLDC 1.0 features, it will also work on top of CLDC 1.1. However, it is probable that most MIDP 2.0 implementations will be anchored in CLDC 1.1. As we shall see, MIDP 3.0 allows for the possibility of J2ME devices running CDC on top of a JVM (not KVM).