Hi,
I would like to know how to make only one trade per Bar. If one trade is opened in current bar, wait until next bar.
thanks

Consider doing something like this on your order creation:

    private int orderCounter;
    private void makeOrder(Instrument instrument, Period period) throws JFException {
        IBar bar = history.getBar(instrument, period, OfferSide.BID, 0);
        for(IOrder order : engine.getOrders(instrument)){
            if(order.getCreationTime() > bar.getTime()){
                console.getOut().println("There is an order already opened within the current bar for "+instrument);
                return;
            }
        }
        console.getOut().println("active orders: " + engine.getOrders(instrument));
        engine.submitOrder("order"+ ++orderCounter, instrument, OrderCommand.BUY, 0.001);
    }