Java Reference
In-Depth Information
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.
6.1 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 in this chapter refers to version 1.1 of
JSR-248 MSA.
JSR-248 defines a Mobile Service Architecture (MSA) that is a step in
the evolution of Java on mobile phones. It builds a Java ME platform
