Getting Started with Java: Installing JDK and IntelliJ IDEA on Windows

So, you’ve decided to start learning Java—awesome! Java is one of the most popular programming languages, and it’s a solid choice whether you’re a beginner or already coding in other languages. But before we dive into coding, there are a couple of things you need: the JDK (Java Development Kit) and an IDE (Integrated Development Environment) to help you write, run, and test your code.

In this post, I’ll walk you through how to install JDK 21 and set up IntelliJ IDEA on Windows. Let’s get you started!

What is JDK and Why Do You Need It?

The JDK (Java Development Kit) is basically your toolkit for developing in Java. It includes everything you need to write and run Java programs: the compiler (to turn your code into something your computer understands), libraries, and the Java Virtual Machine (JVM), which is what actually runs your Java programs.

We’re going to install JDK 21, the latest Long-Term Support (LTS) release. This version will be supported for several years, making it a reliable choice for learning and beyond.

Step 1: Installing JDK 21

  1. Download JDK 21:
    • Head over to the official Oracle site to download JDK 21.
    • Choose the Windows version and download the installer.
  2. Install JDK 21:
    • Run the downloaded installer and follow the instructions. It will usually suggest installing it in C:\Program Files\Java\jdk-21, which is fine.
    • Once the installation is done, we can check that everything went smoothly.
  3. Verify the Installation:
    • Open the Command Prompt (hit Win + R, type cmd, and press Enter).
    • Type the following command “java -version” and press Enter.
    • If everything’s good, you’ll see something like this:
      java version “21.0.0” 2023-09-19 LTS
      Great! Now JDK 21 is installed and ready to go.

Step 2: Installing IntelliJ IDEA

Now that you have the JDK, you’ll want a nice environment to write your code in. While you can technically write Java in a text editor and run it from the command line, using an IDE makes everything easier. One of the best options for Java is IntelliJ IDEA by JetBrains.

  1. Download IntelliJ IDEA:
    • Head over to the JetBrains site and download IntelliJ IDEA.
    • Grab the Community Edition, which is free and has everything you need for Java development.
  2. Install IntelliJ IDEA:
    • Run the installer and follow the steps. Once it’s installed, launch IntelliJ IDEA.

Step 3: Setting Up IntelliJ IDEA with JDK 21

On your first run of IntelliJ IDEA, you’ll need to do a little setup to make sure it’s using the JDK you just installed.

  1. First Launch:
    • When you first open IntelliJ IDEA, it will ask you to choose a theme (dark or light—go with whatever feels right for you).
    • Next, IntelliJ will usually auto-detect the JDK you installed. If it doesn’t, no worries, you can set it up manually.
  2. Manually Adding JDK 21:
    • Go to File → Project Structure → SDKs.
    • Click the “+” icon and choose the path where JDK 21 is installed (for example, C:\Program Files\Java\jdk-21).

That’s it! You’re all set up with JDK 21 and IntelliJ IDEA. Now you’re ready to start writing some Java code.