Java ME on Symbian OS: Inside the Smartphone Model

Chapter 6. Designing Advanced Applications with MSA

JSR-248 Mobile Service Architecture (MSA) is another step in the overall vision of Java technology as a whole and, more specifically, the vision of Java on mobile phones.

We start the chapter by focusing on the MSA specification and trying to answer the major questions that a developer would ask – what is it and what does it consist of? A more pragmatic question – what can I do with it? – follows and we look at various applications that can benefit from MSA. To complement the list of possible applications, we take a specific example of a well-known application, and enhance it using MSA. Finally, we finish with a short section on the next stage of the MSA standardization effort.

What Is MSA?

It is very likely that you have already heard about MSA but, if you have not read the specification yet, there are many questions to be addressed: is it a new set of API packages? is it a successor to MIDP 2.0? and so on. The word 'umbrella' is often used to describe JSR-248 and it describes MSA quite well. Under the umbrella, there are familiar JSRs and no new APIs. The answer to the first question, then, is that MSA is not a new set of API packages; all the APIs scoped by MSA are defined in other JSR specifications. As to the second question, MSA is based on JSR-118 MIDP 2.1 but, unlike the previous MIDP specifications, it also includes other JSRs. Let's now try to say what MSA is, in more depth and detail. Unless stated explicitly, the discussion ...