Just saw your question so it's probably a little late - but here it is anyway. DataChangeEvent contains the ticker, the field, the new and old price:
DataChangeListener lst = new DataChangeListener() {
@Override public void dataChanged(DataChangeEvent e) {
String ticker = e.getSource();
String field = e.getDataName();
double oldValue = e.getOldValue().asDouble();
double newValue = e.getNewValue().asDouble();
}
};