BigDecimal requestedAmount = ...
BigDecimal paymentAmount = ...
In Java to compare BigDecimals I should use
if(requestedAmount.compareTo(paymentAmount) == 0) {
}
For me its not natural to compare numbers in such way and I decided to try to write small technical DSL, and here how looks my code now:
import static com.webbfontaine.twm.accounting.epaylog.utils.CompareDSL.*;
if (eq(valueOf(paymentAmount).comparingWith(requestedAmount))) {
}
if (ne(valueOf(paymentAmount).comparingWith(requestedAmount))) {
}
if (gt(valueOf(paymentAmount).comparingWith(requestedAmount))) {
}
.... and etc.
and here is API/DSL code:
public class CompareDSL {
public static <T extends Comparable<T>> PairToCompare<T> valueOf(T value) {
return new PairToCompare<T>(value);
}
public static <T extends Comparable<T>> boolean eq(PairToCompare<T> pairToCompare) {
return pairToCompare.firstValue.compareTo(pairToCompare.secondValue) == 0;
}
public static <T extends Comparable<T>> boolean ne(PairToCompare<T> pairToCompare) {
return !eq(pairToCompare);
}
public static <T extends Comparable<T>> boolean gt(PairToCompare<T> pairToCompare) {
return pairToCompare.firstValue.compareTo(pairToCompare.secondValue) > 0;
}
public static <T extends Comparable<T>> boolean ge(PairToCompare<T> pairToCompare) {
return pairToCompare.firstValue.compareTo(pairToCompare.secondValue) >= 0;
}
public static <T extends Comparable<T>> boolean lt(PairToCompare<T> pairToCompare) {
return pairToCompare.firstValue.compareTo(pairToCompare.secondValue) < 0;
}
public static <T extends Comparable<T>> boolean le(PairToCompare<T> pairToCompare) {
return pairToCompare.firstValue.compareTo(pairToCompare.secondValue) <= 0;
}
public static class PairToCompare<T extends Comparable<T>> {
private T firstValue;
private T secondValue;
public PairToCompare(T firstValue) {
this.firstValue = firstValue;
}
public PairToCompare<T> comparingWith(T value) {
this.secondValue = value;
return this;
}
}
}
API of course not the best one, but for me it works fine and it was fun to write it :-)
API of course not the best one, but for me it works fine and it was fun to write it :-)
