Complete Guide to Installing Java on Ubuntu 18.04.06

Java is a widely-used programming language and platform that is essential for many software applications. In this guide, we’ll walk you through the step-by-step process of installing Java on an Ubuntu 18.04.06 server.

Step 1: Update Package Lists

Before installing any software, it’s essential to update your server’s package lists to ensure you have the latest information about available packages. Open a terminal window and run the following command:

sudo apt update

Step 2: Install OpenJDK (Java Development Kit)

Ubuntu 18.04.06 comes with the OpenJDK (Java Development Kit) packages in its default repositories. You can install OpenJDK 8, which is a widely-used version, using the following command:

sudo apt install openjdk-8-jdk

This command will download and install the OpenJDK 8 along with its dependencies.

Step 3: Verify Java Installation

Once the installation is complete, you can verify that Java is installed by checking the version:

java -version

You should see output indicating the Java version you installed.

Step 4: Set Java Environment Variables (Optional)

If you plan to develop Java applications or need to set environment variables for Java, you can do so by configuring the system environment. Open the /etc/environment file for editing:

sudo nano /etc/environment

Add the following lines to set the JAVA_HOME environment variable:

JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64

Replace /usr/lib/jvm/java-8-openjdk-amd64 with the actual path to your Java installation if it's different. Save the file and exit the text editor.

Step 5: Reload Environment Variables

To apply the changes, reload the environment variables using the following command:

source /etc/environment

Step 6: Testing Your Java Installation

To ensure that Java is correctly configured, you can run a simple Java program. Create a file named HelloWorld.java:

nano HelloWorld.java

Add the following Java code:

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

Save the file and compile it:

javac HelloWorld.java

Run the compiled program:

java HelloWorld

You should see the output “Hello, Java!” indicating that your Java installation is working correctly.

Conclusion

You have successfully installed Java on your Ubuntu 18.04.06 server. Java is now ready for use in developing and running Java applications. If you need more specific information about Java or have additional requirements, refer to the official documentation or the Ubuntu documentation.