Device Application Management Systems

Device Application Management Systems
All J2ME applications—MIDlets and others—are real Java applications that run under the control
of a Java VM. But what controls the Java VM, for instance on a mobile phone? There's no
command shell from which you can invoke your favorite Java applications like you do on your
workstation. Starting, stopping, and managing the execution of J2ME applications is controlled by
application management software (AMS) that resides on the device. In fact, the AMS controls the
entire application lifecycle, from installation, upgrade and version management, to removal of
application software.
The device manufacturer typically provides the AMS software. This is the most logical scenario
because AMS software must work in conjunction with the device's native system software, which,
presumably, the manufacturer knows best. Nevertheless, third parties can also develop AMS
systems for specific devices. AMS software could be written, for example, in Java or in some
native language such as C.
Understanding the issues surrounding application management is important for the J2ME
developer. Chapter 10 discusses application management. You must be aware of the ramifications
of your choices regarding packaging, licensing, charging for use, and so forth, and how these
decisions will affect the usability and viability of your software.