For Linux: Connect to your Linux instance via port no. 22 using SSH. Please refer this article: https://docs.thinkwithwp.com/AWSEC2/latest/UserGuide/AccessingInstancesLinux.html  Sign-in credentials: Username: ubuntu Refer this article to get started with this product - https://wiki.openjdk.org/display/loom/Getting+started 

Here are some CLI commands through which we can verify the product is present in machine. To view the version of java: java --version Now, we can write a simple hello world program in java for testing purpose: First, create the Java program file as follows: sudo nano hello.java Next, add the following Java code to the file below: public class hello { public static void main(String[] args) { System.out.println("G'day from LinuxCapable!"); } } Then, Save the file CTRL+O, then exit CTRL+X. Next, compile the code using the following terminal command javac: javac hello.java or javac --release 11 hello.java Finally, run the Java code with the following command: java hello

You can follow this article to write a simple java code and test your java: https://www.linuxcapable.com/how-to-install-openjdk-11-on-ubuntu-20-04-lts/