I will answer shortly
My strategies (robots), the indicators work perfectly in cTrader / cAlgo but dont works on java whitout errors but maybe it JForex side issue

Platform JForex sometimes works sometimes not
and place limit orders is a disaster
indicators are displayed or not
or I need a little more practice ....
ps. I started to learn and java and c # at the same time.
For those who want to save a little stress and not waste time : I recommend C# and cAlgoRegards