Apache Jakarta and Beyond: A Java Programmeramp;#039;s Introduction [Electronic resources] نسخه متنی

10.10. Beyond This Book

There is more that could be said about all three of the tools discussed in this chapter, although the material presented will go a great deal toward the creation of any application, Web-based or otherwise.

Hsqldb can be run in server mode and can even be tunneled through HTTP for use behind firewalls. In this mode, combined with cached tables hsqldb makes a very respectable database server for small applications or groups. At the other end of the scale, hsqldb is small and light enough that it can be run on many PDAs that support Java, making it possible to carry a full-featured database in one's pocket. Hsqldb also supports an impressive subset of the SQL standards, and readers are encouraged to check out the details at the hsqldb Web site. Beyond the standards, it is possible to extend the built-in types and functions through custom Java classes. See the class mappings in the script file for an introduction to how this works.

DBCP and Pool both have numerous other configuration options for allocating and reclaiming objects. It is also easy to pool things other than collections. There are also some interesting possibilities in persistent stores, where the pool itself is maintained in a database.

Finally, OJB is a very large, complex suite, and it was only possible to scratch the surface of its features here. A particularly important point is that OJB supports two industry standards for persistent objects. The first is ODMG (Object Data Management Group), which is a comprehensive, general, language-neutral specification for persistent objects. The second is JDO (Java Data Objects), a specification based on ODMG and refined through the Java Community Process.