Disappointed by Jigsaw delay? Java Modularity is here today!

I recently heard that some people are expressing disappointment over the lack of a built-in module system in Java 8, now that Jigsaw is delayed. Some are apparently even looking at technologies other Java because of this. Well, I'd like to point out that There is No Need To Wait! All the modularity that your application needs is already available with OSGi! OSGi pretty much supports everything that Jigsaw was planning to support to allow modularization of applications. And OSGi has more features such as a dynamic lifecycle and a very useful services model. Still OSGi frameworks can be remarkably small. Of the popular implementations Apache Felix is probably the smallest with its implementation in under 500kilobytes. But Eclipse Equinox and our own JBoss OSGi Framework inside AS7 are also very good opensource implementations.

Want to learn how to use OSGi? Like many people I like learning stuff by reading a book. Recently a number of books have been published that provide really good explanations of how to use OSGi, notably OSGi in Action, OSGi in Depth and Kirk Knoernschilds Modular Architecture book, but probably my favorite book is Enterprise OSGi in Action. Besides containing a good description of a number of Enterprise OSGi specs, it also describes really well why certain things are done in OSGi they way they are, which give you a nice and deep understanding of the technology. Additionally it contains some great chapters on how to get your build, test and development environments to work smoothly with OSGi. Enterprise OSGi in Action will be in print later this year, but you can already get it in electronic form from here.

Besides the books, the OSGi Javadoc can be very useful and if you really want to know the details of it all, the OSGi specs are a great resource. Oh, and don't forget to check out the Wikipedia page that shows where you can get implementations of the various OSGi technology.

So in short - no need to wait or turn away from Java if you need Modularity. OSGi is here today and has been used in production by numerous users for many years, just get started by downloading one of the opensource implementations and try it out!