Hello,
i tried to code a strategy based on bollinger bands but i couldn't achieve it.
Is there something out there who is sommething like this that i could modify, the strategy is easy :
- buy if price was under lower bolllinger band and is now over it
- sell if price was over upper bollinger band and is now under it.

From approach standpoint the algorithm is similar to the following strategy in wiki:
https://www.dukascopy.com/wiki/index.php ... SMA_Simple
See here more, on how to work with Bollinger bands:
https://www.dukascopy.com/wiki/index.php ... nger_Bands
Also this example works with Bollinger bands (value retrieval and logging):
https://www.dukascopy.com/wiki/index.php ... ing_values

Keep us posted if you need any further assistance on this.

I've almost done my strategy but i've one other question, where could i put a conditional close of my strategy ?
After this ?

      double stopLossPrice, takeProfitPrice;

      // Calculating stop loss and take profit prices
      if (orderCmd == OrderCommand.BUY) {
         stopLossPrice = history.getLastTick(this.instrument).getBid() - getPipPrice(this.stopLossPips);
         takeProfitPrice = history.getLastTick(this.instrument).getBid() + getPipPrice(this.takeProfitPips);
      } else {
         stopLossPrice = history.getLastTick(this.instrument).getAsk() + getPipPrice(this.stopLossPips);
         takeProfitPrice = history.getLastTick(this.instrument).getAsk() - getPipPrice(this.takeProfitPips);
      }

In SMA Simple example strategy already two close conditions get applied - stop loss and take profit prices (in IEngine.submitOrder call). What kind of additional close condition do you want to apply? Is it time or price condition?

I want to add a close condition when the price crosses the sma(middle bollinger line)

Then you should do it in onTick method, since you want to close the position as soon as the price condition gets fulfilled. If you need any further assistance on this, please provide the relevant code fragments.

What i've written don't does what it should do, take a look :

5 downloads and no answer...
No one has an idea ?

1) instead of:

return engine.submitOrder(getLabel(instrument), this.instrument, orderCmd, this.amount, 0, 20, stopLossPrice, takeProfitPrice);

try

IOrder order = engine.submitOrder(getLabel(instrument), this.instrument, orderCmd, this.amount, 0, 20, stopLossPrice, takeProfitPrice);
return order;

And then you won't need to use additional variables like buyopen and sellopen, but then it will suffice to check:

order.getOrderCommand() == IEngine.OrderCommand.BUY

2) Why do you use such huge TP and SL? If you don't want to use those values, then just set them to 0 or rather use an IEngine.submitOrder method without them, see:
https://www.dukascopy.com/client/javadoc//com/dukascopy/api/IEngine.html#submitOrder(java.lang.String,%20com.dukascopy.api.Instrument,%20com.dukascopy.api.IEngine.OrderCommand,%20double)

3) Use tick and bar filtering (filter also instruments):
https://www.dukascopy.com/wiki/index.php ... Ticks/Bars

4) Please consider logging your values to see what execution paths get taken and why:
https://www.dukascopy.com/wiki/index.php ... ing_values

5) If you still encounter some problems, please describe more precisely:
a) The intended algorithm.
b) What you expect the strategy to do.
c) And what it does instead.

I don't think that it's a huge SL and TP, to better explain what i want to do i'll show you a screenshot :

The remark about the TP and SL was made just to provide you with extra information on order submission, in case you needed it.

I've entirely reprogrammed the strategy and now it works better, i have just one little problem : it doesn't allocates dynamically the trade volume.
For example, if i've 100.000$ in my account i want to open exactly a 1 million transaction.

See:
https://www.dukascopy.com/wiki/index.php?title=Account_Info

I tried this but it opens too big positions :

public void onAccount(IAccount account) throws JFException {
      double compte = account.getCreditLine();
      amount = compte/1000000;
   }

IAccount.creditLine() returned amount is in units (e.g. USD, if it is your account currency), but for orders amount is in millions, so you snippet returns an order amount which would equal your all available credit.