Spring Data JPA with QueryDSL: Repositories made easy

Spring Data JPA removes much boilerplate from repository code and QueryDSL can be used to create clean and reusable query specifications. When combined, we can create powerful repositories with very little code.

Easy Command Line Interface coding with JCommander

Implementing a command line arguments parser can turn quickly from ‘yes it’s just one parameter’ to a heap of for loops with curious string manipulations and conditionals in-between. Try and test that. I guess we’ve all been there. Using apache-commons-cli makes life easier and has been the defacto standard for most projects that require a command line interface (cli) as it makes writing cli’s reasonably easy. However, when I discovered JCommander by C├ędric Beust my way of making cli’s changed for the better!. Let me share it with you:

CSS3, lightning talks and foosball on KTM

Last Wednesday, June 22th, 42 had its quarterly KTM (acronym for Knowledge Transfer Meeting), a day packed with technology, business updates and food with drinks (or maybe the other way around).

Atlassian Summit 2011 Wrap Up

We have finally recovered from the jetlag, impressions and hangovers related to the Atlassian Summit 2011, so it is time to wrap up on all the good things we have seen and heard in San Francisco.



42 sponsors GOTO Amsterdam conference

42 Has signed up as a gold sponsor for the GOTO conference. We are very glad that a conference with this reputation has decided to expand to Amsterdam and we support its objectives to offer high-quality content and inspire the community.

Java Repository Bridge library in practice

For the past couple of weeks we’ve been blogging about the Java Repository Bridge (JaRB) project. For those who are not yet familiar with JaRB, I recomment reading our introduction post first. In previous blog posts we described the various components of JaRB in isolation. During this blog post we are going to use all previously mentioned components to create an actual Java EE application and show what kind of advantages JaRB offers.

Drop XML: configure your Spring web application in Java

Since Spring 3.0, configuration of your application context is possible in Java (using the @Configuration annotation). But it is only now maturing to a point where you can fully configure your web application, with the coming release of Spring 3.1 (milestone 2 was released just a few days ago). This blog post describes how.


Using database constraints in Java

It is very common to define constraints on databases to ensure that only “valid” data is stored. Yet we do very little with these (powerful) database constraints in our Java applications. Often we duplicate the constraints in our application, for example by using JSR-303 constraint annotations.

The idea behind JARB - JAva Repository Bridge

The object-relational mapping philosophy has to deal with the problem of setting two different paradigms up for a workable relationship. Not the easiest of tasks. Hibernate has done a good job at this, being the de facto implementation for the Java Persistence Architecture (JPA). Still, there are some itches to be scratched, especially from a Test Driven Development point of view.