Can someone show me some sample code on how to implement isLong & getOpenPrice methods?
I am trying to identify whether an existing order is long or short and get the original open price in order to set a new stop loss.

Ok I have some spare time so..

First of all, you have to obtain the order, e.g. by label like so:

IOrder order = engine.getOrder(String label); //Returns order by label, or null if no order was found

Then you proceed with:

if (order != null)
   if (order.isLong()){
        double openPrice = order.getOpenPrice();
        ...
  }

Pretty straightforward.. How about reading the api here: https://www.dukascopy.com/client/javadoc//

if you don't know precisely the label of your order you can use this:

for (IOrder order : engine.getOrders(instrument)) {
       if (order.isLong()) {
           double openPrice = order.getOpenPrice();
    }
}