thejavajar

Just got home from presenting Spring Roo at the Tampa JUG. Everything went pretty smooth; basically did a demo of building a simple app with a few JPA entities. Then I imported the the project into Spring Tools Suite and ran it on tc Server. I created a few entities, did some updates and then opened up Spring Insight. People were impressed with what Insight has to offer. Vladimir Vivien contributed to the presentation by discussing some details of the internals of Roo and we both discussed the advantage of having something like Grails or Roo when looking for paths to productivity. Most of the JUG members in attendance were impressed with Roo but there still was this feeling of uncertainty about code generation and the ‘magical’ things happening in the background. All I know is that productivity is something that Spring Roo brings to table and the ‘magical’ things happen to reduce Java complexity so we can focus on getting the job done. Thanks to all of the JUG members who attended.

Google App Engine’s support of Java was a long awaited, highly demanded feature of the service back when I first started messing around with original, Python version a little over a year ago. The excitement that App Engine brought to developers was echoed by the overwhelming request for Java support. Over the past 10 days I have created a few sample applications locally to give it a test. I went the App Engine Eclipse plugin route to get things started. It is a really nice plugin that delivers what you would expect from Google. Once installed, you can create a project and have it running in under a minute.

Once I got familiar with what I was working with, I decided to turn this sample application into a simple Spring Web Flow 2 demo. That is where development stopped. Unfortunately, there are a lot of JVM features/classes that are not accessible on App Engine that Web Flow 2 (and 3rd party libraries) needs for binding and flow execution support. Nothing against Google or SpringSource, I just did not get what I wanted.

Fortunately, I created a new sample app that is based on Groovy’s Groovlet technology and things were moving forward again. Just configure the GroovyServlet in your web.xml file and away you go. My next experiment will be to work with Grails on App Engine via the Grails App Engine plugin.

Overall, App Engine is great. It is really easy to use and the application dashboard features are amazing. Access to application and admin log files in a nice HTML based presentation. Quota detail that explains bandwidth, CPU and datastore utilization along with access to different versions of your application.  You can even grant access to other developers for collaboration efforts. All features you normally do not get from your company’s “Enterprise” admin group.

On a side note, Vladimir Vivien and I will be discussing Google App Engine at the Tampa JUG on August 25th, 2009.

On March 31st, 2009 I discussed Spring’s dynamic language support with a focus on Groovy and JRuby at the Tampa JUG. There were quite a few people in attendance who were interested in leveraging the power and simplicity of Spring and Groovy. The presentation material can be found here and the demo Web application can be found here. Thanks to all who attended, the Tampa JUG’s sponsors GCA and Hudson and Vladimir Vivien.

Vladimir Vivien and I had a great time Tuesday night at the Tampa JUG presenting an introduction to Grails. We stepped away from the standard Tampa JUG presentation format and only put together a few presentation slides and then did some live coding. We created a small Grails application from scratch, working with just a few domain objects to demonstrate contraints, relationships and Grails’ convention. I worked from the command line and with TextMate and Vladimir worked with IntelliJ and the JetGroovy plugin. I think we had a great group of developers in attendance who were interested in what Groovy/Grails has to offer. We had a lot of great questions and I know some of our attendees were really impressed with how quickly we got up and running with our Grails application. Even though we went over our normal time limit, we didn’t have enough time to really get into all the details and features of Grails but I know some of the Tampa JUG members that were in attendance are at home or at work creating their own Grails projects. I have posted the slides here and our JUG demo here.