private String getLabel(OrderCommand cmd) {
return cmd.toString() + UUID.randomUUID().toString().replace('-', '0'); // + System.currentTimeMillis();
}
////label order comm


public void onTick(Instrument instrument, ITick tick) throws JFException {
if (!ordersSubmitted)
{
ordersSubmitted = true;
// engine.submitOrder("LABEL", Instrument.EURCHF, IEngine.OrderCommand.BUY, LOT , Price, Slip, SL, TP, GTC; "note"
engine.submitOrder("Buy_EURCHF", Instrument.EURCHF, IEngine.OrderCommand.BUY, 0.001, 0, 2, 0, 0, 0, "B");
engine.submitOrder("Sell_EURUSD", Instrument.EURUSD, IEngine.OrderCommand.SELL, 0.001, 0, 2, 0, 0, 0, "S");
engine.submitOrder("SellUSDCHF", Instrument.USDCHF, IEngine.OrderCommand.SELL, 0.001, 0, 2, 0, 0, 0, "S");


}}

One solution used by may is to auto generate a label with a unique number. Example:
protected String getLabel() {
String label;
label = "IVF" + generateRandom(10000) + generateRandom(10000);
return label;


}

private static String generateRandom(int n) {
int randomNumber = (int) (Math.random() * n);
String answer = "" + randomNumber;
if (answer.length() > 3) {
answer = answer.substring(0, 4);

But the simplest easiest way is to add to the label System.currentTimeMillis which is unique and continuously calculates time
in milliseconds since 1 January 1970. Example:

public void onTick(Instrument instrument, ITick tick) throws JFException {
if (!ordersSubmitted)
{
ordersSubmitted = true;
// engine.submitOrder("LABEL", Instrument.EURCHF, IEngine.OrderCommand.BUY, LOT , Price, Slip, SL,TP, GTC; "note"
engine.submitOrder("X"+System.currentTimeMillis(), Instrument.EURCHF, IEngine.OrderCommand.BUY, 0.001, 0, 2, 0, 0, 0, "Buy");
engine.submitOrder("X"+System.currentTimeMillis(), Instrument.EURUSD, IEngine.OrderCommand.SELL, 0.001, 0, 2, 0, 0, 0, "Sell");
engine.submitOrder("X"+System.currentTimeMillis(), Instrument.USDCHF, IEngine.OrderCommand.SELL, 0.001, 0, 2, 0, 0, 0, "Sell");


}}
//:)

protected String getLabel() {
String label;
label = "IVF" + getCurrentTime(LastTick.getTime()) + generateRandom(10000) + generateRandom(10000);
return label;
}

private String getCurrentTime(long time) {
SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT_NOW);
return sdf.format(time);
}

private static String generateRandom(int n) {
int randomNumber = (int) (Math.random() * n);
String answer = "" + randomNumber;
if (answer.length() > 3) {
answer = answer.substring(0, 4);
}
return answer;
}