[Java] Improve how-to document/run Java cookbooks recipes

[davisusanibar]

Currently Java cookbooks recipes are examples runnable on JShell environment and compare the results.

For this purpose JShell environment is needed.

The purpose of this ticket is to create new ways about how the same code could be run without JShell dependency:

• Current testcode is able to run inside public static void main method without problems, base on this one idea could be to add this line on the recipe to te user could copy all the lines and run that without to adding that contend inside a method, and delete that at runtime for JShell process
• Other options ...