I recently bought a license to Dave Flanagan’s Jude. I have enjoyed Dave’s books on Javascript, Ruby and of course the Java in a Nutshell series. I was a little disappointed that the Nutshell Java book didn’t get an update to reflect Java 6 and looking for more information I took a trip to Dave’s site and saw an updated version of Jude. I had tried it before but preferred the paper version of the book (it’s initial sections on Java features are still models in the genre).

However with no new edition in the offing I decided to buy Jude and process my Java 6 JDK. Jude basically reads the Javadoc and code in the target JDK and then serves that information out via an in-application HTTP server which you point your browser at.

Recently I have been switching between several “post Java” languages: JRuby, Groovy, Scala and Jython. In all of them though I have needed to know what exactly the details of the Java Library API are so I can access them via the host language. The other day I was filing a bug report and needed to know the details of the Charset object, as I was flicking between between Jude and the report I wondered, “When did this app become indispensible?”.

It might be argued that all you need is Google and the Sun Javadoc but Jude has a few features that make it much more useful. Obviously it useable offline, that’s not something to be sniffed at. Secondly its search and browsing features are intuitive and “right” for the domain. I find it a lot easier to browse through hierachies and leap between classes and packages using Jude’s dedicated tools than via Google. It has also replaced the not inconsiderable heft of Java in a Nutshell from my work bag.

If I could make one change to make it even more useful I would make the default search much more liberal than it is now. The search accepts Java RE which is great for power using but you shouldn’t have to enter /.*http.*/i to find every instance of a class with any variation of HTTP in it, you want to be able to just type “http” Google-style.