IBM has published another article in their alt.lang.jre series, this time on JRuby. JRuby is a pure Java implementation of the Ruby language. Ruby is often described as an object-oriented scripting language, and it combines the pure OO features of Smalltalk with powerful scripting features along the lines of Perl or Python. I have used various scripting languages (mostly Perl and Ruby) here and there, but never long enough to really become proficient in any of them....
I just spent an hour playing with Groovy, and I have to say that it is very promising. I have not experimented a whole lot with the actual Groovy syntax, but based on what I have read as well as on my limited experiments, Groovy is a nice mixture of popular scripting languages such as Ruby or Python, but geared towards Java programmers. The syntax borrows many useful elements from other scripting elements but remains similar enough to Java to enable Java developers to easily learn this language....
Martin Fowler shares some thoughts on JUnit, mostly about why JUnit instantiates a new instance of the test class for each test case. As usual, he has some good points. The posting also contains some information on JUnit’s TestSetup feature, which allows several test cases to share a single setup and teardown routine.
There is a free book on Subversion version control. I have not had a chance to look at Subversion yet, but I am planning on upgrading my CVS installation at home (which I am keeping out of principle more than anything, as I don’t actually do all that much development at home these days) to Subversion.. Before my current job, I actually had not used CVS for about 5 years, as my previous companies used Visual Source Safe, StarTeam, and Perforce....
Prevayler 2.0, a prevalent persistence engine, was released a few days ago. This is the first time I have heard about this project or about this type of persistence engine, but it sounds very promising. Prevayler can be used in lieu of a (relational or object-oriented) database in many cases. It is based on simple mechanisms that are built into the Java language, in particular serialization. The idea is that the engine tracks and logs any changes in (due to commands being run on) your business objects....