Install the JDK and build an application

Install Java

Now that you have an Axion instance running Ubuntu 24.04, you can SSH into it via the Google Cloud console:

This will bring up a separate window with a shell connected to your instance.

This Ubuntu image does not include Java, so you need to install it. First update apt:

    

        
        
sudo apt update

    

Then install the default Java Runtime Environment:

    

        
        
sudo apt install default-jre

    

Check to ensure that the JRE is properly installed:

    

        
        
java -version

    

Your output will look like this:

    

        
        
openjdk version "21.0.3" 2024-04-16
OpenJDK Runtime Environment (build 21.0.3+9-Ubuntu-1ubuntu1)
OpenJDK 64-Bit Server VM (build 21.0.3+9-Ubuntu-1ubuntu1, mixed mode, sharing)

    

Once the JRE is installed, you will want to install the default JDK:

    

        
        
sudo apt install default-jdk

    

After completion of the JDK installation, check the version:

    

        
        
javac -version

    

The output will look like this:

    

        
        
javac 21.0.3

    

Deploy Spring Petclinic

spring-petclinic is an example Spring-based application that is simple to build and run.

First, download the repo:

    

        
        
git clone https://github.com/spring-projects/spring-petclinic.git

    

Next, enter the cloned directory and run the build script:

    

        
        
cd spring-petclinic
./mvnw package

    

This will build the jar file. Once built, you can test the web server by running the jar:

    

        
        
java -jar target/*.jar

    

Once the application is running, you can open the web app in a web browser by visiting

    

        
        
http://<EXTERNAL_IP>:8080

    

Where <EXTERNAL_IP> is the value you obtained in the last section .