3] Run a Java or JAR file. Now when you double click on the JAR file, it will automatically run like how EXE files execute. If there is a problem with version, the file should inform you.

I wanted to write simple Java code from scratch to test this Hello.java, so I created a "new folder" as my project root and a "src" folder to put java files, and copy "Hello.java" to the folder. Then ...