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that is rich in features and reflects the current market needs. MSA
broadens the JTWI standard by standardizing support for technologies
and features that are already available on many devices (and, specifically,
on Symbian devices). The MSA environment is backwards compatible
with the old JTWI. Due to the advancements in the mobile industry and
Java specifically, MSA is aligning around a broader set of devices which
have much more powerful capabilities. However, the intent is still to
align on high-volume mobile devices and not to create a challenging
standard which would be difficult for low-end devices to comply with. As
you may expect, MSA is also designed to be future-compatible with the
forthcoming MSA 2.0 environment. (Although an early draft of JSR-249
MSA 2.0 is available for public review at the time of writing, some of the
Component JSRs are still in very early stages and therefore MSA 2.0 is not
discussed here.)
The MSA specification's primary goal is to reduce fragmentation of
mobile Java environments. An aligned mobile Java standard makes life
easier for ISVs and developers by giving them a cross-device Java ME
platform which is highly predictable and helps them to make sure that
their applications work on a wide variety of MSA-compliant devices.
The basis of the MSA environment is the CLDC 1.1 Configuration and
the MIDP 2.1 Profile. This means that familiar MIDP MIDlet applications
can run on an MSA-compliant device. On top of the MIDP/CLDC envi-
ronment, MSA defines a normative collection of what it calls 'Component
JSRs': the JSRs that are referred to in the JSR-248 specification and which
live under the MSA umbrella.
Looking at MSA only as a collection of JSRs is misleading. There are
other important elements in JSR-248, such as clarification requirements in
the Component JSRs to improve predictability and interoperability. MSA
also includes additional new mandatory requirements related to JTWI,
security, supported content formats, and so on. MSA also adds optional
recommendations that should help those implementing Java ME platforms
to create an optimal MSA-compliant implementation.
It is important to note the structured approach to fragmentation man-
agement in the MSA specification, which actually defines two MSA
platforms. When vision meets reality, it is always challenging, espe-
cially when considering the big capabilities gap between smartphones
and mid-range devices. To ensure consistency for both high and low
device segments, JSR-248 defines two platforms: full MSA targets high-
end devices and MSA Subset targets mid-range devices. Both have
well-defined conditions for features that may not be available on all
MSA-compliant devices. This enables the MSA specification to be used
across the widest possible variety of horizontal markets and customer
As for CDC-based platforms, both MSA and MSA Subset can be imple-
mented on top of CDC as long as the underlying implementation complies
with JSR-248. However, although MSA with CDC is an interesting topic to
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