Native Modules Bridges React Native

I have an issue when i try to bridge an Native Modules.

I have a function in Java , the function will calculate the progress when i write a byte , i have a while loop at there. The problem is whenever i return the value inside of loop , the loop is gonna be broke, but if i put the return value outside of the while loop its gonna return the value only the calculation done which is in this case (only once). I want return an increment value from the while or for loop process. when i log the index its shown correctly . Honestly i have no knowledge about Java

 public void sendData(String message,Promise promise) {

    if(message.length() < 1) {
      return;
    }

    byte[] data = new byte[message.length() / 2];
    for (int i = 0; i < data.length; i++) {
      int index = i * 2;

      String hex = message.substring(index, index + 2);
promise.resolve(index)

      int v = Integer.parseInt(hex, 16);
      data[i] = (byte) v;
    }
    serialPort.write(data);
  }

You should handle this sending events from Java and listen for them in JS. You can use DeviceEventManagerModule.RCTDeviceEventEmitter for this purpose.