protected PersistentQuantity doInvertSign(final PersistentQuantity q)
throws PersistenceException {
final Fraction amount = FractionManager.getTheFractionManager().invertSign(q.getAmount());
final PersistentQuantity res = Quantity.createQuantity(amount, q.getUnit());
getThis().getQuantities().add(res);
return res;
}
@Override
public PersistentQuantity createQuantity(
final PersistentAbsUnit unit, final common.Fraction amount) throws PersistenceException {
// amount in FractionManager suchen oder neu erstellen.
final String fractionStroke = "/";
final String enumeratorString = amount.getEnumerator().toString();
final String denominatorString = amount.getEnumerator().toString();
final String fractionSearchString = enumeratorString + fractionStroke + denominatorString;
common.Fraction persistentAmount;
try {
persistentAmount = FractionManager.getTheFractionManager().getFraction(fractionSearchString);
} catch (final NotFoundException e) {
persistentAmount = amount;
try {
FractionManager.getTheFractionManager().addFraction(fractionSearchString, persistentAmount);
} catch (final DoubleDefinitionException e1) {
System.out.println("error while fraction creation");
}
}
final PersistentQuantity newQuantity = Quantity.createQuantity(amount, unit);
getThis().getQuantities().add(newQuantity);
return newQuantity;
}