How to Install Default JDK on Ubuntu 24.04 LTS

Java Development Kit (JDK) is essential for developers working on Java applications. Ubuntu 24.04 LTS provides a straightforward way to install the default JDK, which ensures you have the necessary tools to develop and run Java applications. This guide will walk you through the process of installing the default JDK on Ubuntu 24.04 LTS.

Step 1: Update the Package Index

Before installing any package, it’s a good practice to ensure your system’s package index is up to date. Open your terminal and run:

sudo apt update
sudo apt upgrade -y

This will ensure you have the latest software updates and dependencies.

Step 2: Install Default JDK

Ubuntu repositories include a package named default-jdk, which installs the most commonly used version of the JDK.

Run the following command to install the default JDK:

sudo apt install default-jdk -y

This command will install the OpenJDK version recommended for Ubuntu 24.04.

Step 3: Verify the Installation

Once the installation is complete, you can verify the JDK installation and check the installed version using the java command:

java -version

The output should display the installed version of OpenJDK. For example:

openjdk version "17.0.8" 2024-09-24
OpenJDK Runtime Environment (build 17.0.8+10-Ubuntu-1)
OpenJDK 64-Bit Server VM (build 17.0.8+10-Ubuntu-1, mixed mode, sharing)

Step 4: Set the JAVA_HOME Environment Variable

For some applications, you might need to set the JAVA_HOME environment variable. Here’s how to do it:

1. Open the environment configuration file:bashCopy codesudo nano /etc/environment
2. Add the following line to the file, replacing the path with the one where Java is installed:bashCopy codeJAVA_HOME="/usr/lib/jvm/java-17-openjdk-amd64" Save the file and exit.
3. Apply the changes:bashCopy codesource /etc/environment
4. Verify the JAVA_HOME variable:bashCopy codeecho $JAVA_HOME The output should display the Java installation path.

Step 5: Test the Installation

To ensure everything is set up correctly, you can compile and run a simple Java program:

1.Create a file named HelloWorld.java:

nano HelloWorld.java

2.Add the following code:

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

3.Compile the program:

javac HelloWorld.java

4.Run the program:

java HelloWorld

You should see the output:

Hello, World!

Conclusion

You’ve successfully installed the default JDK on Ubuntu 24.04 LTS. With Java ready to go, you can now develop and run Java applications. If you encounter any issues or need a specific version of the JDK, consider exploring additional installation methods, such as downloading Oracle JDK or using SDKMAN.

Happy coding! 🚀