CDJUG June meeting

I was at the Capital District Java User Group (CDJUG) meeting yesterday and it was quite an interesting experience. For starters, I wasn't sure if I was going to the meeting until the last minute, and I didn't even know if I was going to stay the whole time. Secondly, at the last minute I was pleasantly surprised that there were going to be 2 presentations at the meeting.

Anthony will be posting the presentation slides in the next few days on the site, but in the meantime, I'll write a few notes from the meeting.

THe first presentation was on the Sleep (JVM) scripting language by Raphael Mudge. He was a very energetic guy, and it was quite a bit of fun just listening to him. Good work Raphael ! Now, the presentation was great, but I personally am far from being convinced that this is something that I will be investing my time into. Here's the deal:

1. I've already dabbled into at least a couple of JVM scripting languages (Jython in the past, and now Groovy). THere is a couple of dozen more scripting languages on the JVM which are all interesting to mess around with. Thus, in order to convince a developer to spend time with the language, a scripting language needs to have a number of different characteristics. Granted, Raphi has quite an interesting character, the conversation with him before the presentation was very engaging. At the same time, as with any open source project, the key factor in whether the project will survive is the size of the community. Now, I know Raphi said that there were a bunch of people using the scripting language; however, as it is with a bunch of other open source projects, typically the top 1-2 contenders in the space gather 90+% of the developer attention and community. Although the other languages are not necessarily doomed to fail, they have to find their own niche and a set of committed developers in order to survive. Granted, it seemed like SLeep already has a niche by being used in jIRCii; however, it appeared that Raphi was the sole significant developer. So, the question is, what happens when/if he loses interest ?
2. Raphi specifically mentioned that he's not trying to be all things to all people, and considering that it is a much smaller project and community than the other scripting languages, that is a very reasonable goal. However, in order to win developer mindshare, it seems to me that having a decent size standard library with utility functions and being able to call into the JVM for everything else, it's not enough any more. I'm judging from my personal experience: one of the major selling points of Groovy to me was that it DID have the convenient, easy xml processing, JDBC access, command line interface, etc. etc. etc, all on top of its seamless integration with the JVM.
   
3. Now, this is just me, but I never grokked the Perl syntax. Seriously, this was probably the first language that I looked at when I was first trying to understand what web programming was all about (10 years ago).. and today, I'm still looking at the syntax and it can never fit into my skull...
   
4. A couple of notes on the presentation:

• I didn't quite get it if slee was able to extend the classpath at runtime. Raphi showed thate there was an interactive console (big plus in my opinion, Groovy still kinda sucks in this area); however, one big selling point for me was that at any point I could throw in a couple more jars to the classloader and start loading classes from there.
  
• Raphi mentioned that it was his intent to have a clear separation between the sleep program and where it calls into Java; however, for me personally, that was a downside. I found the method calls to be kinda cryptic ( I couldn't quite follow what was happening in a couple of nested method calls - I admit, it might just be my fault, as I haven't seen Objective-C syntax on which the Sleep syntax is based). At the same tie, I didn't see any type of bean properties (e.g. instead of doing foo.setBar('baz'), doing foo.bar='baz'), which for a scripting language is a must in my opinion.
  
• The documentation seemed to be excellent
• All the time when I was looking at the presentation, I was thinking that after NetBeans 6.0 comes out, he should have a Schliemann module for Sleep syntax. :-)
  
• Runtime size was pretty small , big plus for embedding uses...
  

Now, the second presentation was the main reason why I went to the meeting. It was about NetBeans by the author of Pro NetBeans IDE 5.5 Enterprise Edition, Adam Myatt. I was really thrilled to meet him as I had heard from Anthony that he lives in the Capital District area, and that he's a big NetBeans supporter. I was also really looking forward to checking out his book as I had read a couple of good reviews. Adam did an excellent presentation, he was on his game, and I have rarely seen someone present so many things in such a tight and organized manner. He did an excellent job at presenting NetBeans to the people who had gathered and received a very positive response - one of my coworkers actually re-installed NetBeans the next day and was trying stuff out with it. Way to go , Adam ! One thing that totally blew me away during the presentation was the relatively small footprint of NetBeans. When he was doing the demo of NB 5.5.1, the memory rarely went above 100 MB, and I was quite impressed since he was doing quite a bit (and his laptop was not the greatest to begin with). Considering that he did everything from UML diagrams to Visual Web Pack demos, I was VERY impressed. Then, when he was doing the NetBeans 6.0 preview, I was even more impressed as it hovered around 50 MB - AMAZING !

I was personally a bit disappointed that I didn't learn too much from the presentation. I understand that I was not the target audience for it, as I've been a NetBeans user for quite a long time, and I knew 99% of the stuff that Adam talked about. He was covering a lot of ground (more width than depth) as was necessary to present to the majority of the audience. But all in all, I liked the presentation and I'm looking forward to the next time we meet up : maybe we might even get a chance to talk a bit..

JVM scripting languages review

I've been playing around with groovy for the last couple of weeks and I have to say that I am intrigued by it. In the beginning, when I was starting to hear that there was a Groovy JSR that was aiming to create a standard Java scripting language, I was a bit skeptical : I've been using Jython for the last couple of years for the same puprose and so far it has been working out great for me. I already have a number of working application at work that are doing great. I even bought the "Jython for Java programmers" book a few years ago and it was an excellent guide in getting started. Additionally, in the last few months I've been getting back into the same book on the more advanced topics such as embedding jython in other applications (I even have a little prototype NetBeans plugin that is a live Jython interpeter, very nice in exploring the NetBeans APIs)

So, I said that Jython was generally working well for me for the same purpose. However, I did have a couple of things that bug me about it:
- Because Jython is an implementation of Python on top of a JVM, it is forced (or at least expected) to move at the same speed that python does. So, although Jython works pretty well for JVM scripting and and is generally feature complete, since it's a couple of releases behind Python proper, there is a lot of pressure to keep up with the language. Since one of the reasoning for using Jython is that you can either reuse python skills on the JVM, that really doesn't translate very well since Jython cannot use Python features implemented natively. Thus the "python skills transfer" thing doesn't really work.

- Although I really like the Python newline handling and indentation, it is kinda messed up that it's difficult to use python inside web pages or directly from the command line ('cause you have to maintain and respect the white space, which works great inside a regular script but it sucks when you try to do something like "jython 'for i in os.listdir("."):\n print i\n \n'"... which could have been so much better if there was another delimiter

- Because Jython has to implement the Python APIs, for a java developer to use Jython (e.g. because of the concise syntax or scripting features) he/she has to learn the totally new Python syntax and libraries (although Java most likely has equivalent APIs, using the Java APIs is not consice).

So, back to Groovy. I was initially a bit cynical, since Jython was really doing it for me (for the most part). I remember reading how the Groovy APIs were so unstable, and that it wasn't particularly catching on.. After all, I was a faithful Jython user.

So, one day I decided to give it a shot, and now, after reading about it, I am starting to really like it. For the most part, it appears to have all the goodness of Jython (e.g. concise map or list syntax, etc), however, without having to learn a totally new API. It enhances and improves Java and the JVM (e.g. Grails is really doing some really interesting things on top of Hibernate with GORM). It has a whole bunch of "best-of-breed" features taken from Ruby and Perl, without having to comply with a particular formal specification that isn't particularly Java related (e.g. such as the Python spec). It has Java-like syntax and delimiters and Java code could be used "as is" inside Groovy. Additionally, talking about syntax, it can be used nicely from the command like as in "groovy 'for i in [1,2,3] { print i }" - assuming that the for loop is correct.

All in all, so far Groovy has been really nice. I am really looking forward to the Groovy in Action book coming out so that I can dig more into it. The only thing that I really miss from Jython so far is the interactive console. I mean that Groovy that have a graphical groovy shell that can be used to execute Groovy statements, however, each statement is executed as a separate script and the results of the statements do not build up inside the script context (which might be easily fixable, but so far I don't know enough about it to fix it right off the bat).

Jython developer blog

Frank Wierzbicki has started a developer blog for Jython. Make sure to check up on the progress there.. Frank Wierzbicki's Weblog: Weblog Announcement