THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
You will need the Java Software Development Kit aka SDK or JDK. (Note: Not only the Java Runtime Environment or JRE, you need the full JDK)
If you are running Linux, you can choose to use the OpenJDK. On either Linux or MS-Windows, you can choose to use the Oracle JDK.
The following environment variable settings have proven valuable.
...