Check for Java installation

[johannesstrueber]

Hey thanks for the script,

i just ran from the start_node_v2 script from a default pi image which does not have java installed. Maybe you could add a check like java -version and depending on the result resolve it intosudo apt install default-jdk

Im currently in the process of setting one pi up :)

[ladopixel]

Hi!

I had thought about doing so, that's why I have the notice.
But I think installing a certain version of Java depends a lot on the computer owner and needs. For this reason I just show the prompt and if the person wants to install Java let the user choose the version and do it on his own.

Although I think it can be good to give the possibility to install Java (optionally) at the beginning of the script in case of not having it on the computer.