Back from JaZOOn, Second Day

26. June, 2007

Well, modern medicine worked it’s usual miracle and my brain was much less clogged today. I went to the keynotes but left a bit disappointed. The history of the web and REST was nice to see but my interest in the past is usually reduced to use it as a source for cynical comments about mistakes that bite us today, and there wasn’t much in it for me in that regard. The second talk just contained nothing that I didn’t knew already. Well, you can’t always win.

Next, I went to see a software demonstration (Automated (J)Unit Testing) but I had seen that one before so I left early and attended Hibernate Search: Unstructured Search for Hibernate instead. The group around Emmanuel Bernard managed to extend the query API of Hibernate for Apache Lucene. Nice work, easy to use, looks promising. If you have a web application which allows users to search for something, this is definitively something you should try. Like Google, you can offer a single text field and the search results will be ranked in an intelligent way. Cool.

After lunch, I enjoyed the The Zen of jMaki. They have started to collect all and every JavaScript Web widget set out there, wrapped all of them in the same way, so they get much more simple to use. I don’t like JSP’s and tag-libraries but they have done a nice job and the demos looked real enough to believe that this can actually help.

In the same room, I watched David Nuescheler Blitzing the Content Repository: AJAX meets JCR. He developed a little JavaScript library called “R-JAX” which allows to create something that resembles CRUD with a JCR and a few lines of HTML. Since you can access the Content Repository via HTTP, all you need to do is to copy all files (JavaScript, HTML, CSS, etc.) into the repository and then make sure you use the right (relative) URLs and you were ready to go. This JCR stuff also looks very interesting. I hope I’ll find the time to have a closer look at Apache Jackrabbit one of these days.

Of course, when you do a lot of AJAX, you need to test it somehow. Ed Burns held the talk Java Platform Automated Testing of Ajax Applications where he compared four different tools to do this (some commercial, some OSS) and Webclient a.k.a. MCP (Mozilla Control Program) which allows to embed a web browser in a Java program and control it from a unit test (so you can load a web page, examine it, check AJAX requests, etc). GWT gets you only so far with their own testing framework (especially since it’s insane to setup and some things (like UI elements) can’t be tested at all. MCP solves all that but you have to deploy the webapp somewhere. Choose your poison.

Right now, MCP can only run Firefox (but they are working on getting at least IE on Windows). It would be nice to see the same integration on Linux using the IEs4Linux project. You did know that you can run IE on Linux, didn’t you? Not that anyone ever wanted (except for those web pages which stubbornly refuse to display correctly in Firefox … and for those, who insist on Flash 123.5 which will come for Linux in 2150 … but who needs them anyway).

The next talk was obvious: Java and Scripting: One VM, Many Languages. Rags Srinivas (with hat!) showed us around the Java Scripting API. Pretty low level presentation with little new information. I had hoped for more meat here. The only interesting he mentioned was that Sun doesn’t really care about dynamic languages per se. They care that as many of them as possibly run on the Java VM but not the languages themselves. That probably explains the strange maneuvering in the last months: Hiring key Ruby developers, working on standardizing Groovy (JSR 241 and then suddenly JavaFX is the Next Great Thing(TM). Actually, JavaFX just seems to be another building block in a growing forest (some would say swamp) of dynamic languages flourishing around Java.

Smells a lot like .NET (one runtime, any language you like) and probably makes sense. There are so many common problems (Singletons, DB access, HTML generation, mixing HTML and Java) which you can’t really do well in Java but perfectly well in other languages which don’t (have to) drag the Java legacy along. Java is ten years old, now, and it begins to show. GC was a fantastic new feature when Java came out, but today, every contender for the language of the next decade can do that. In Java, Beans, lists, maps and other, important types and concepts are second class citizens. To create a simple list and sort it, you have to write ten lines of code. In Groovy, you write:

def list = ['a', 1, 'b']

1 is of course turned into an Integer. Try that in Java 5 and the vital information, the data in the list, is drowned in syntax to club the compiler into silence:

import java.util.Arrays;
import java.util.List;

public class Foo {
    List list = Arrays.asList (new Object[] { 'a', 1, 'b' });

The sad part is that I had to start Eclipse to make sure that the syntax is correct. The Java code is six times as long and only 1/6th of that is actual information. The rest is only there to make the compiler happy. 😦

Back to Jazoon. I would have loved to attent the BOF’s, especially the ones registered by Neil M. Gafter about Java Closures and something else (I forgot) but I still wasn’t too well and didn’t want to risk to have to miss the last two days.

All in all, I enjoyed this day. My thanks go to the JUGS guys for organizing it.

Back from JaZOOn, First Day

26. June, 2007

During the keynote speeches, someone mentioned that the streetcar no. 5, which goes to Jazoon’07, also goes to the zoo of Zurich. The good news was that the zoo was at the other end of the line, so JaZOOn (which apparently doesn’t mean anything) is either not related to the zoo or it’s related in such a way that it’s the opposite.

I kind of disagree. A zoo is a place where you can see things that you normally can’t and in a safe way. In this regard, Jazoon is a zoo full of Java animals and I’m a happy part of it.

Yesterday, I attended the keynote given by Ted Neward which was “Why the Next Five Years Will Be About Languages”. He mentioned a lot of interesting things, like:

  • Tools to build custom languages (a.k.a DSL’s) become more simple, more powerful, more widespread
  • The need to use there tools grows because it takes so much to formulate some things in general purpose languages like Java. What was great ten years ago seems clumsy today.
  • There is a plethora of languages that run on the Java VM (which is not Java(TM)) like Groovy, JRuby, Jython, Nice, Rhino (see here for a more complete list). He mentioned something like 200 languages using the VM besides Java but my memory could fail me here.

For me, this means that my own talk What’s Wrong With Java?, where I compare Java, Groovy and Python, probably wasn’t that far off. Of course, I was pretty nervous how people at a Java conference would take it (plus I got sick on the weekend, so I had to take so many drugs to be able to give the talk that, if I had fallen into the Lake of Zurich, they would have had to pump it dry and deposit the water as medical waste 😉 … anyway …).

Moreover, I had to rush through my talk because the time limits were really tight. All in all, I felt my performance could have been better but the critics seem fair. (see Fabrizio Gianneschi’s comment, thomas and another blog). Also, the room in my talk was full of people; something I haven’t seen for any other talk since (which probably means that I attend the wrong ones ;-)) and comments at the show were good, too (but I can’t prove it).

I was thinking about registering a BOF but I just don’t feel well enough, so I’ll expand my thoughts and ideas a bit more here where space and time are only limited by your and my endurance. And you can think about your comments before sharing them with the world. Win-win, I’d say.

Back to Jazoon. After my own talk, I attended Space Based Architecture – Scalable as Google, Simple as Spring. The talk itself was interesting and made sense; unfortunately, my body demanded sleep and it takes what it can’t get. So if you want to know any details, ask the person who sat next to me. I can only pray that I didn’t snore. Not the fault of the speaker, I swear!

After having restored some of my energy, I went to see Impossible Possibilities – Programming Java an Unusual Way. The presenter, Michael Wiedeking, has the same problem with English as I: Great pronunciation but small built-in dictionary. Still, I could get what he talked about. He presented a way to implement a generator/corouting in Java 5. The basic idea here is that you have a piece of code which can return something to the caller and then continue it’s work when the caller calls it again. Confused? Here is an example:

def parse(filename):
    handle = file(filename, 'r')
    while True:
        line = handle.readline()
        if line[0] == '#':
        yield line
        # <-- If you call parse() a second time, you will be here.

parse() throws away every line that starts with a hash (#) and returns (“yields”) all the rest. The interesting part is when you call parse a second time: It will not start with the line where a new file is opened but it will continue with the next statement after “yield”, therefore reading the next line in the already opened file.

In Python, you can have as many yields in one method or function as you like. They work with recursion and exceptions. This way, you can run a complex algorithm until a certain point (when you have a first result to return), return it and then go on as if the return had never happened. You don’t have to worry about local variables, closing the file handle, control flow. The language all handles it for you.

If Java, you achieve the same thing with two threads and about four or five hoops to jump through. This is the difference between a modern dynamic language like Python or Ruby: There are completely new ways to do things that are very powerful, simple to understand and (almost) impossible to do in Java.

I spend the rest of the day with Michael Wiedeking and Neil M. Gafter, arguing about checked exceptions until I was to tired that I crept home and went to bed.

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