Groovy, a Java-like Scripting Language

I wrote a simple script to automagically backup a mysql db in it just to test how easy it was to write stuff versus say bash or ruby. It ain't pretty. Firstly, it's well documented from an API point of view but there are almost no examples on the website beyond trivial code.

Secondly, it's obviously early. The release says beta, and two things stick out like sore thumbs:

1. debugging is really quite unclear for anything beyond simple brackets because it spits out full Java Exceptions which you have to parse rather than tell you the line number and what it thinks went wrong; it's in there but you have to dig.

2. there's a distinct lack of convenience libraries. The real power behind most scripting languages isn't the syntax it's the libraries that have been implemented that make them useful. Just look at Python, Perl and Ruby. The libraries are really what make you want to use it.

At this point, groove is a *great* start, but until it has the breadth of library functions of something like Ruby it's a bit of a pain to use for general scripting. Yes you can use all the Java classes and that's great, but it also means you have to start structuring your script like a Java program which defeats the point of using a scripting language in the first place.

I think the niche uses of JUnit testing and Ant are where it will get it's initial traction and that's not necessarily a bad thing.

For example, here's how I got a simple formatted date out of groove
<code>
def getFileDate() {
#This is ugly
calendar = Calendar.getInstance()
calendar.setTime(new Date())

year = calendar.get(Calendar.YEAR)
month = calendar.get(Calendar.MONTH) + 1
day = calendar.get(Calendar.DAY_OF_MONTH)

#Force to String to Keep Leading Zero
String amonth = month < 10 ? "0" + month : month
String ayear = year.toString()
String aday = day < 10 ? "0" + day : day

return amonth + "_" + aday + "_" + ayear
}
</code>

It's basically weakly-typed Java. A better way would be for me to have some sort of convenience method that parsed say a unix 'date' style string and returned a formatted date string; I guess I'll have to write it myself :) Over time I'm sure the issue of helper methods will be sorted out and I look forward to future releases, but right now it's frustrating.

On the plus side, the great things that stand out are autoboxing of variables, much more relaxed syntax and useful constructs for looping across objects. With time I think this will become a useful tool in the arsenal of any Java developer. I think it would be great if they could set up a cookbook on the codehaus website with recipes, this would ease the learning curve enormously and help build a community spirit.