Conclusion
The current version of the MIDP specification is an interim set of APIs that reflects a particular point in the development of mobile telephone technology. At present, mobile phone developers must work within the constraints of current devices and work around the constraints of the platform as best they can. Although the limited CLDC/MIDP libraries constrain multiple aspects of Java application development, there are a number of initiatives in place to support applications migrating down to smaller devices, including small footprint XML parsers and databases.

Regarding JDO and whether or not it could be implemented to run on a MIDP device, our conclusion is that while MIDP alone cannot realistically host a full JDO implementation, a distributed implementation that combines local processing with server support can indeed meet our application needs. Not only that, but such an architecture actually opens up a more challenging set of options for truly distributed systems that provide for widely distributed data and processes.

The real challenge for MIDP developers is to build applications that not only work locally on a single device but can interact and synchronize with multiple nodes of different types in a disparate architecture. In practice, running JDO on a single device provides few advantages over alternative APIs for data access. However, a distributed JDO implementation that integrated and synchronized data across multiple nodes, encapsulated behind a single distributed object model, could be a very valuable tool.

From our discussion of JDO as an example of serious application development, we can see that developing software for mobilized architectures requires us to consider a range of aspects of design and implementation in order to identify the optimum configuration. MIDP alone cannot provide a fully featured Java deployment platform. But, by playing to its strengths, such as the ability to maintain a persistent local data cache and support it with server-side resources, it opens up a range of new opportunities in software development.

References

• Open Source, Open Sesame?

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