Being a long time Eclipse user I recently started using IntelliJ. Here are some notes on how I use it for Java and Kotlin. I will probably update this post continuously.

Comparison

Here are some of the topics that I thought were most interesting when doing the switch.

Free and Open Source

I don't want to depend on software that is not free and open source. That, to me, feels like a trap and something I want to avoid.

Eclipse is free and open source.

IntelliJ has a community edition that is also free and open source. This is the one I use.

This is totally fine for me. Less is more!

Synchronize Settings

I want to automatically have my IDE setup exactly how I want it and synchronize that to all my installations. Avoiding the time consuming task of searching for settings and clicking checkboxes.

In Eclipse I use Workspace Mechanics. The mechanics files are put under version control so that all developers of a project will have changes applied immediately when someone changes the settings.

In IntelliJ this is built in. In the menu, File -> Settings Repository you can add any git-repository. I just created a new repository on GitHub and is now using that clone URL. To publish settings you do File -> Settings Repository and click Merge.

I have seen that some settings are not synchronized when using IntelliJ. I really miss automatically download sources and documentation and most annoyingly is the option to optimize imports on the fly.

Opening Several Projects In Same Window

In Eclipse you would create a workspace and import projects in that workspace.

In IntelliJ you create a project and add modules to it. A module can be a Maven, or Gradle, project. You do:

• File -> New -> Project ...
• Empty project
• Name it anything you like
• Finnish

Now to add a Gradle project to it, you do:

• File -> New -> Module From Existing Sources...
• Select the build.gradle file. If it were Maven you would select the pom.xml file

Maintaining a Code Standard

In Eclipse you can setup save actions that will apply the code standard whenever a file is saved.

In IntelliJ I have not found any way of enforcing a code standard. It does a good job on understanding and adhering to how the current file already is formatted.

I always use an external tool for coder formatting, if I can find one. So that developers can use any editor. But sometimes I am not the maintainer of the project or other developers don't agree with me about doing it that way.

Automatically Boost Code Quality

In Eclipse I would setup save actions to automatically do things like:

• Remove unused variables
• Organize imports, sorting and removing unused imports
• Adding final keyword to immutable attributes and variables
• Remove trailing white space

In IntelliJ you can find these settings by simply searching in the settings menu (File -> Settings).

This will organize the imports when you are working with a file. You can also batch this by marking a folder in the menu and press CTRL-ALT-O.

Compilation errors

In Eclipse I let Eclipse compile the code whenever I change anything. I immedely get clear feedback if any code does not compile.

I struggle with this in IntelliJ. It does not tell me about code that does not compile.

If I manually browse to a file that I know does not compile, and open it, IntelliJ will tell me it does not compile.

This is annoying as I keep getting compilation errors when building outside of IntelliJ which slows me down.

Reveal file in project view

In Eclipse I can reveal whatever file I open in the project view to the right.

It can be done in Intellij also.

Show projects and their parts

Eclipse does a really good job showing me projects and their parts. The project, source-folders, packages and files.

In IntelliJ I found flattern packages.

But it is not as clear as with Eclipse.

Conclusions

I am missing some features in IntelliJ regarding automatically correcting things in the code. But that is easily solved with Maven or Gradle. I wrote about that here.