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Speaking at jDays 2015

Last week I spoke at jDays 2015 in Gothenburg with the talk Grails and the real-time world.

I arrived on March 16th after almost missing my connection in Frankfurt (as there are no direct flights from Madrid I had my connection there). Although we landed in time I had only 50 minutes before the other flight departure. We stopped in front of the terminal more than 15 minutes after we could got off the plane. Besides that, I was seated in the row 33 of the plane so I was blocked until the whole plane got off. After that, I ran across the terminal but I finally catched the next flight to Gothenburg. For my returning flight to Madrid it was pretty easy. That time I arrived at gate A47 and my flight to Madrid was at gate A46 🙂

That same day at 18:00 we had the speakers dinner. These speakers dinners, part of most of the conferences, are a great place to talk with other speakers outside your comfort zone about many things. I started talking in a group of five and, with some beers, we introduced ourselves and also talked about the topics that we were to present the following days.

The following day, March 17th, the conference started. There were many interesting talks related to the Java ecosystem. The talks I liked the most were:

  • The opening keynote by Ola Bini: He talked about the Future of Programming and some things that we need to be prepared to face. Specially about privacy and security.
  • Be a better developer with Docker: tricks of the trade by Nicola Paolucci: Although I already had heard about Docker, the talk opened my eyes. Docker is a nice way to set up a development, staging or even a production environment with all the dependencies that you need to use in isolated containers for every component.
  • Pragmatic Functional Refactoring with Java 8 by Raoul-Gabriel Urma: Raoul gave a great talk about refactoring your Java apps with functional concepts in mind. He showed some code and after some iterations he refactored it using lambdas and functional interfaces. For a Groovy developer this is not that mindblowing because we’re used to using Closures all the time, but it’s great to see that the Java language has finally evolved.
  • Microservices and Modularity or the difference between treatment and cure by Milen Dyankov: The talk started with the microservices buzzword but Milen gave a different vision and talked about what really means going to a microservices architecture. He said that you need to start building your software “easily” and that means building a monolitic application but with the modules and the frontiers between them clearly defined. Then, after your application evolves, if you really need to go to microservices it will be very easy because your application was developed with modulatiry in mind. The demo was also very good. He started with the Glassfish EJB demo application and he was refactoring the app to build loosely-coupled components that interact each other. Then, he extracted some dependencies to a Spring Boot app, a JEE container, a Liferay portlet, even an OSGi service… very easily because the architecture of the application was built with modularity in mind.
  • HTTP 2.0 & Java: Current Status by Simone Bordet: This talk was great. Simone introduced the problems of using a very old protocol as HTTP1.1 for 2015 web development and all the hacks the developers need to do to increase performance. Then, he introduced HTTP2 and explained why it’s important to move on. Then he explained that the main web browsers already support it and Jetty (where he’s a committer) also supports it. He emphasized that we, the developers, need to push the change and a way to do it is just filling bugs for the projects that still don’t support it: apache, nginx, tomcat,…
  • The life of a Java method inside the HotSpot JVM by Rickard Bäckman: This talk was a little bit hard but it was great. Rickard is an Oracle employee working on the JIT compiler in the HotSpot JVM. He told us all the amazing things that the JVM does trying to optimize our programs. He talked about method inlining, the interpreter, the different C1 and C2 compilers,… Definitely a great talk not applicable for the day-to-day work but very useful to know a little bit about how the JVM works under the hood.

And about my session, everything was fine. There wasn’t many people in the room (I guess that Grails is not a trending topic in a Java conference) but I think the attendees enjoyed the talk, specially the demos. If you are interested, the slides and the code are availble at my Slideshare and Github account.

The venue of the conference was really nice and the organization was also very good. I only missed one thing: There was no closing session for the conference. After the last talks everybody pick their stuff and went home. I believe that it’s important to have a formal closure for the conference. It doesn’t need to take much time but I think that these last 10 or 15 minutes are very important for the conference and the attendees. Anyway, everything was great!

With this talk I have started what my Kaleidos mates have called #IvánOnTour2015. It turns out that I sent some proposals to many conferences around Europe and almost all of them have been accepted. So, for the next months I’ll be on tour speaking at: Greach, ConFess, Spring IO, GeeCON and GR8Conf.
and GR8Conf.