Prerequisites

• A Webdock Ubuntu Server (Ubuntu 24.04 in my case)
• SSH access to your Webdock server

Installation Steps

First, we need to update and upgrade our server.

$ sudo apt update
$ sudo apt upgrade

Now we need to check if we have Java installed on our server. To do so, we run the command “java” if the server responds with the “command not found” it means that it is not installed and we need to install it.

If you’re a Java developer you will also need to install the Java compiler which is part of the Java development kit. We can check with the command:

In this case, we see that neither java nor javac is installed, so here are the steps to install them.

Depending on which app you want to install, you may need a certain version of Java to be installed.

To see which Java versions are offered in your Ubuntu distribution, run:

$ sudo apt-cache jdk

This command will search and output the different Java development kit versions available.

For example, to install Java 21, you have to install the below package.

$ sudo apt install openjdk-21-jdk

In this guide, we’ll install the default package which will install the latest version. Since we’re using Ubuntu Noble, the command we will use to install java will be:

$ sudo apt install default-jdk

Input 'y' to install the package.

Once installed, we can check if the server is ready by running the commands java and javac again.

Run "java" on the command line to verify if Java is installed.

Run "javac" on the command line to verify if the Java compiler is installed.
Once we have java and javac installed you’re ready to go. We can test a program like “Hello World” to make sure everything is working properly.

First, we make a class called Hello.java and paste the following code snippet.

$ vim Hello.java

Copy and paste the below code snippet.

public class Hello{


public static void main(String[] args){

            System.out.println("Hello Webdock!");

            }

}

Then, we compile the code with javac. If the terminal doesn’t return anything, it has compiled successfully.

$ javac Hello.java

Finally, we can test that Java is working by running our program with the command java.

$ java Hello

Conclusion

That's it! This guide provided instructions to install the latest or specific version of Java on your server. I hope you find this guide useful. If you have any issues, don’t hesitate to contact our support team.

This article was written by Webdock Support Specialist Jose Porras. Jose is passionate about Cloud Hosting and helping Webdock Customers succeed wherever he can.