IntelliJ IDEA Community Edition
Quick Set-up Notes

Russell Bateman
May 2025

You can do a lot using the IntelliJ IDEA (free) Community Edition. This is how to set that up.

IntelliJ IDEA, an integrated development environement (IDE), is typically referred to as "IDEA."

Preliminary step—the JDK...

Ensure that you have downloaded a JDK that is open source (not from Oracle) that will allow you to develop and distribute software. I suggest the Temurin™ JDK.

I download and copied the exploded subdirectory to ~/dev (/home/russ/dev). I typically do not change my host's notion of what JDK it's running to this download. However, for the JDK I develop with, here's what that looks like: 

russ@nargothrond:~/Downloads$ ls -lart
...
-rw-rw-r--  1 russ russ  206919519 May 16 12:17  OpenJDK21U-jdk_x64_linux_hotspot_21.0.7_6.tar.gz
russ@nargothrond:~/Downloads$ tar -zxf OpenJDK21U-jdk_x64_linux_hotspot_21.0.7_6.tar.gz -C ~/dev
russ@nargothrond:~/dev$ ls -lart
...
drwxr-xr-x  9 russ russ  4096 Apr 15 16:28 jdk-21.0.7+6

Setting up IntelliJ IDEA Community

Now follow these steps; later, I'll be using the new JDK I just downloaded.

  1. Download the IDE from https://www.jetbrains.com/idea/download/?section=linux. I'm installing the Linux download. If you want other, try IntelliJ IDEA and click the Download button. You should find links for Windows, macOS and Linux.
  2. Scroll down to where there's a download choice for the IntelliJ IDEA Community Edition and click the button. This is free—it's not a 30-day trial version.
  3. Choose a resting place for your download. I personally like ~/dev (or /home/russ/dev). Or, you can choose /opt/idea for a more professional placement, but you'll have to resort to sudo to get it there, set it up and get the permissions right.
  4. Explode the downloaded tarball onto the path you want to use: 
    russ@nargothrond:~/Downloads$ tar -zxf ideaIC-2025.1.1.1.tar.gz -C ~/dev
  5. (You will see a new subdirectory containing the name idea-IC- .... The "IC" gives away that this is the Community Edition you have downloaded.)
  6. There are myriad ways in Windows, MacOS or Linux by which you install an icon on the desktop or in the panel at the bottom (or top) of the window (etc.). Choose one if you are used to this. It exceeds the purpose of these notes to cover that.
  7. Otherwise, to launch by hand, just open a terminal, make your working directory ~/dev (or wherever you put IDEA) and run it from the command line: 
    russ@nargothrond:~/dev$ ./idea-IC-251.25410.129/bin/idea.sh

Opening a project...

The easiest way to run a project in IntelliJ IDEA is to have one already that you cloned in git or other into your filesystem. If that project has a proper Maven pom.xml, you can open it with no worries.

You don't have to have a pom.xml or a correct pom.xml, but, if you do, the project will open without errors, missing relationships or any kind of difficulty you'll have ultimately to correct. It means that importing a proper Maven project (probably Gradle ones too) is easy-peasy.

To open the project, on the splash screen of the newly launched IDEA, just click on the Open button, then navigate to where you laid the project down in your filesystem, and click OK.

What to do once in the project?

Because IntelliJ IDEA has just been set up, any project will not be ready develop before the JDK you set up is loaded into Project Settings. Here's how to do that.

  1. Launch IDEA.
  2. Open a project by clicking on Open. (Maybe the project you want is already opened because you opened it.)
  3. Click on the hamburger menu (something like ☰) at the upper left of the IDE window.
  4. This should reveal the File menu; choose Project Structure....
  5. Click on SDKs under Platform Settings.
  6. In the middle column, at the top, there is a + sign to add an SDK; click it.
  7. Choose Add JDK from disk....
  8. Navigate to and select the JDK I suggested earlier that you add. Mine was ~/dev/jdk-21.0.7+6 for the example in these notes (see Preliminary step—the JDK... higher up in these notes).
  9. Click OK.
  10. Next, back in the left column, click on Project under Project Settings.
  11. In the pane to the right, in SDK:, click on (what is probably) <No Project SDK> and select the new JDK you downloaded. In my example, this was temurin-21.
  12. At lower right, click Apply or just click OK to dismiss the Project Structure dialog.

At this point, you should be ready to do most anything including step through JUnit tests and even write new code.