Java ME on Symbian OS: Inside the Smartphone Model

Chapter 10. Java ME Subsystem Architecture

The final two chapters of this book give you an insight into how things work under the hood of the Java ME platform. If you ever wondered what makes the virtual machine (VM) tick and click or how the Application Management System (AMS), profile, configuration and VM are built and how they interact, then the next two chapters give you a glimpse into the fascinating implementation of Java technology on Symbian OS.

This chapter gives an overview of the implementation architecture, and the interaction and roles of the various entities that comprise the Java ME platform, as a Symbian OS subsystem.^[82] The next chapter deals exclusively with how the Symbian OS Java ME subsystem acts as an abstraction layer for Java applications to make them use the same API calls as native Symbian OS applications. These two chapters are also highly valuable for engineers who work in systems development and integration.

There are a few widespread misconceptions about the Java ME subsystem architecture that will be shattered after reading this chapter. When you have finished, you will easily spot the four mistakes in a sentence such as 'The KVM aborted the MIDlet installation'.

Java Applications and Symbian OS

From the point of view of the Symbian OS architecture, the Java ME subsystem is a replaceable component that Symbian OS licensees can extend, customize or replace altogether. Additionally, the Java ME subsystem, as a whole, is a native application just like any ...