Java Installation

The Java Development Kit (JDK) provides the tools needed to develop Java applications. This guide covers installation on different operating systems.

Note

If you’re using IntelliJ IDEA, the JDK comes bundled with it, so you can skip these steps.

Choosing a JDK

There are several JDK distributions available:

• Oracle JDK: Official Oracle implementation (requires license for commercial use)
• OpenJDK: Free, open-source implementation
• AdoptOpenJDK/Eclipse Temurin: Community-maintained, production-ready OpenJDK builds

For beginners, Eclipse Temurin (formerly AdoptOpenJDK) is recommended due to its ease of installation and long-term support.

Windows

Using the installer

1. Download the JDK installer from Eclipse Temurin
2. Run the installer and follow the installation wizard
3. The installer will set the JAVA_HOME environment variable automatically
4. Verify installation by opening Command Prompt and typing:

   java -version

Manual environment variable setup (if needed)

1. Right-click on “This PC” or “My Computer” and select “Properties”
2. Click on “Advanced system settings”
3. Click the “Environment Variables” button
4. Under System Variables, click “New” and add:
   • Variable name: JAVA_HOME
   • Variable value: Your JDK installation path (e.g., C:\Program Files\Java\jdk-17)
5. Edit the “Path” variable and add %JAVA_HOME%\bin

macOS

Using Homebrew

1. Install Homebrew if not already installed:

   /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

2. Install OpenJDK:

   brew install --cask temurin

3. Verify installation:

   java -version

Using the installer

1. Download the macOS .pkg file from Eclipse Temurin
2. Open the downloaded file and follow the installation instructions
3. Verify installation by opening Terminal and typing:

   java -version

Linux

Debian/Ubuntu

sudo apt update
sudo apt install openjdk-17-jdk

Fedora/RHEL

sudo dnf install java-17-openjdk-devel

Verify installation

java -version

Multiple Java Versions

If you need multiple Java versions, consider using a version manager:

• Windows: SDKMAN for Windows (via WSL)
• macOS/Linux: SDKMAN

With SDKMAN, you can install and switch between Java versions:

sdk install java 17.0.2-tem
sdk use java 17.0.2-tem

Verifying Your Installation

Create a simple Hello World program to test your installation:

1. Create a file named HelloWorld.java with the following content:

   public class HelloWorld {
     public static void main(String[] args) {
       System.out.println("Hello, Java!");
     }
   }

2. Compile the program:

   javac HelloWorld.java

3. Run the program:

   java HelloWorld

If you see “Hello, Java!” printed in the console, your Java installation is working correctly.