Thursday, May 15, 2014

The tools we use: IntelliJ IDEA

As a software editor, most of us spend their days writing (or actually reading) code and the tools we use to do that matter a lot. At Activeeon, we are of course free to choose whatever tool does the job but the majority uses IntelliJ IDEA. Given that the Jetbrains guys recently extended our Open Source license, I can only return the favor by spreading my love for such a great IDE.


I personally switched to IntelliJ 3 years ago and never looked back. When I joined Activeeon, I was pleased to see that IntelliJ was already used and we then convinced other developers to switch. Let me share the reasons on why start coding with IntelliJ and a few tips.

Why switch?

For me, the main reason to switch was the Maven integration. It just works! It is always nice to be able to take a POM file, import it and have all the src and test folders, the dependencies configured. 

To build ProActive we rely on Gradle and I must say it works but it is not as good as the Maven integration. One big missing features for me is the ability to transform dependencies to IntelliJ module dependencies. Let’s say you have several Git repositories, for us Programming and Scheduling, Scheduling depends on Programming but since these are two different repositories we use Maven dependencies between them and not Gradle “project” dependencies. With Maven integration, this situation is detected and instead of having references to JARs in your local repository, IntelliJ creates module dependencies. If you change code somewhere, you see the changes directly in other modules in your IDE. Unfortunately, this does not work with Gradle apparently due to some limitations around the Gradle tooling API.

The Maven or Gradle integration is one thing that is really nice with IntelliJ : the support of many tools, languages and frameworks. HTML, Javascript, CSS, PHP, Python, Ruby, Groovy and Java of course, they all have decent support out of the box. It very pleasant to stop fighting with incompatible plugins and versions to get a working IDE.

New user? Learn one shortcut!

CTRL+SHIFT+A is the shortcut to remember because it will help to find all the other shortcuts. Simply type what you are trying to do.

Code navigation

Given that, as a developer, you spend more time reading code than writing it, you have to be efficient when it comes to navigating in your code base. Just learn the shortcuts that help you move quickly between files, code blocks,...

While doing that remember that IntelliJ is quite smart and you often don’t have to type everything, just type some characters that appears in the name. For instance if I type CTRL+N (go to class) and then RST, it will suggest to open RestSchedulerTest class.


IntelliJ indexes a lot of things making the search fast, in my IDE, I have all of the ProActive projects opened and it is just handy to check if a refactoring affects other projects. Just make sure that your project folders are well recognized to avoid indexing unnecessary files like build/ or target/ folders.

Code editing

Smart completion is often presented as a killer feature in IntelliJ. I personally don’t notice it anymore, it just works. This is maybe the best way a feature can work, by having the user not even noticing it.
For me, coding is often a matter of hitting the completion shortcut, the refactorings shortcuts and the intention actions shortcut (ALT+ENTER), I’m thinking about what the code should do and my IDE takes care of the boilerplate.

What could be improved?

The Gradle integration is definitely something I would like to see improved, mostly the issue I mentioned above about project dependencies and the build file editing support (so slow right now!).

I also had one issue with my dual screen setup and windows focus but this is probably more related to Java and Xorg. So I had to disable the option to grab the “focus follow mouse” option in XFCE.

Wrap up

If you are not already using it, just give it a try. The community edition is free and open source. The ultimate edition has more features and it is not that expensive given the amount of time you spend in your IDE. Jetbrains offers discounts for startups and educational purposes. And they even allow you to use the ultimate edition on your open source project, thanks for that!

Good tools are essential to build good software. Be it your machine, the operating system or the IDE, you need them to be productive. Along with SSD technology, Linux and Bash, IntelliJ IDEA is one tool I could not live without.

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