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ri=uleof thumb: Dont us != or == To compare strings. They are meant for numbers

in the while loop of getGoodProvinceCode() u didnt tell the while loop how to break if 'prov= "" '. Hence it continues running that loop which resulted into the stackoverflow error.
The solution...

why not replace the != with < and see if any error concerning that still remains

Try doing some stuffs with the java.lang.Runtime. it has a getRuntime class and exec() method.

I'm looking for a way to kill proceses on my machine from my java program just like task manager