This chapter introduced the concept of creating a shared database to provide interoperability between the .NET and J2EE platforms. In addition to covering the open access drivers that are available for both platforms, we looked at how the DAO pattern can be used to provide a unified way of accessing a database that's shared between the two platforms. You also saw how this data sharing can be extended by providing a level of notification between the two platforms, using some point-to-point interoperability concepts.
It's important to realize that we've only scratched the surface of the capabilities of both ADO.NET and JDBC. The aim of this chapter was to introduce a simple approach to the topic and show interoperability between the .NET and Java platforms when both are accessing a shared database. This approach of course can be expanded to include the more advanced features of database connectivity for both platforms.
Next we'll look at how message queue technologies can be used to provide interoperability at the resource tier effectively extending the updates/ notifications that you saw in the DAO pattern and formalizing a process of sending asynchronous messages between .NET and J2EE.