In the last post, I talked about the first day of The Developers Conference. Now lets talk about day number 2.

Very different from the previous day, this one started full of coding. And during the day, we kept seeing lighting talks and Vinicius’ toys. The only real problem we had was that the place ran out of eletricity for a while… but at least it didn’t last too long and the event could finish right.

Rod Johnson

The first speech was again from Rod Johnson. But this time, it was not philosophical at all. He presented Spring Roo, a project that aims at bringing to Java the productivity found in Rails. After seeing what he showed, I believe it. And love it.

In summary, the tool generates a lot of boilerplate code that we would otherwise have to write ourselves. And keeps it all out of the way while you develop your project.

I liked this so much that Spring Roo will be covered in a new post, exclusive to it, soon enough. And look, I don’t like Spring, but this thing can make me change my mind.

Lightning Talks

One of these lightning talks was about Spring best practices, which followed Spring Roo’s presentation. Ricardo Jun presented it, and mentioned things like how people tend to simply want to totally discard xml, instead of using it in moderation; the importance of using tools; the importance of modularization and also that we should always mind concurrency.

Another quick demonstration about robotics had an application server installed in a device, which was accessed through http. This device was connected to a lamp, and Vinicius turned it on and off through a web interface. Meaning: I want all the power plugs in my house accessible through the internet!! =D

On the note of excited people, I must talk about Vinicius Senger again. When presenting the balloon robot for the second time now, he breathed Helium, the gas used in the balloon to make it float. The effect was that his voice got very thin for a few seconds, creating a very funny moment.

Another lightning talk was about what was previously called Web Beans – now Weld: the reference implementation of JSR 299: Contexts and Dependency Injection. Alessandro Lazzarotti, from Red Hat, gave a quick demo on the implementation which is, of course, full of annotations everywhere.

An interesting lightning talk was about performance in JPA. Alberto “Spock” talked about how the Open Session in View filter pattern can be a little bit outdated when it comes to ajax applications – an environment which wasn’t there when the pattern was created.

In Globalcode’s blog here, he explains this problem better. During the presentation, he also mentioned the Apache Myfaces Orchestra project, which should also help minimize the problem bringing the conversation scope to your application. The conversation scope was first introduced by JBoss Seam, and brings us a scope bigger than request, and smaller than session, which can really help us manage resources in a lot of situations.

Mike Keith

This time Mike Keith presented about JPA 2.0. The goal of JPA 2.0 is basically to standartise what we currently do with, for example, hibernate, because we can’t with JPA 1. Nothing really new was presented – unless you didn’t know anything about JPA 2 already. But a few topics are worth mentioning.

A new evictall function was added. Useful to completetly clear cache between test cases. Small change but sounds interesting.

Now my pet peeve: the new criteria API. He presented it and showed a few examples and comparisons between the criteria code and the JPQL code. Just made me dislike it more. Just as a reminder, I already said that I don’t like this thing when I wrote about Globalcode’s Casual Class #006. Trying to access a database completely through OO code is just too much purism. At least, Mike is a very funny presenter to watch =)

Francisco Gioelli (Google)

The original plan was to have Chris Schalk talking about Google App Engine. Unfortunatelly, he had problems with the immigration and couldn’t get into the country. So google sent Francisco Gioelli, who did a nice job instead.

Among other languages, Google App Engine allows us to write Java web applications and publish them on the google cloud, leaveraging from the monstruous google scalability. A few features available include possibility of scheduling cron tasks through a xml file and the Big Table, their (non-relational) database. This last feature is the only thing that makes me a little bit worried about using google’s cloud.

This talk had a demo and was complemented by another one from Rafael (from Globalcode) – this last one using JSF 2.0 – nice! Two little extras mentioned by him: each request can take at the very most 30 seconds and the internal server used seems to be Jetty.

Alejandro Guizar (Red Hat Mexico)

This one was about BPEL. This is not a topic I can talk too much, so I won’t. The only thing that took my attention was something called BPEL Unit. I never heard of it and found interesting that such a thing exists. But I couldn’t find any good references…

Cloud Computing Panel

To close the event, a panel on Cloud Computing, featuring the main speakers that were present. This is a trendy topic nowadays, full of buzz words, but interesting, it was!

Ed Burns started talking that Sun have something (I forgot the name…) since 2000. Makes sense… very tipical of Sun: great products, terrible marketing. He also mentioned Zembly.com. If you are insterested, go to the site now. I just went there and found out that they are closing the service permanently from November 30th. Nice… (no, not really).

From Rod Johnson, we learnt that Springsource have their hand on Cloud Computing in the form of CloudFoundry. Also, he made sure to say how important it is to have multiple players in the market. Agreed.

Some points were easily agreed by the panelists:

• private clouds will have big importance in the future;
• a good thing of the cloud is the economy;
• but a bad thing is the loss of control in a lot of senses, but probably mainly data;
• we need easy of migration between cloud providers.

Someone asked about cloud computing and peer-to-peer. The panelists didn’t seem to believe too much in this possibility. Well, who knows…

Last picture, to change the mood a litle bit:

And so it ends this year’s event. I’m already waiting for the one next year! =D