org.opentripplanner.transit.model.basic.Money Maven / Gradle / Ivy
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package org.opentripplanner.transit.model.basic;
import java.io.Serializable;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.NumberFormat;
import java.util.Currency;
import java.util.Locale;
import java.util.Objects;
import java.util.function.Function;
import javax.annotation.Nonnull;
import org.opentripplanner.framework.lang.IntUtils;
/**
* Represents an amount of money.
*/
public class Money implements Comparable, Serializable {
public static final Currency USD = Currency.getInstance("USD");
public static final Money ZERO_USD = Money.usDollars(0);
private final Currency currency;
private final int amount;
/**
*
* @param currency The currency of the money amount
* @param minorUnitAmount The amount in the smaller currency unit, so for 1.50 EUR pass 150.
*/
private Money(@Nonnull Currency currency, int minorUnitAmount) {
this.currency = Objects.requireNonNull(currency);
this.amount = minorUnitAmount;
}
/**
* Creates a Euro money object.
* @param amount Amount in fractional euro, so 1.5 for 1.50 EUR
*/
public static Money euros(float amount) {
return Money.ofFractionalAmount(Currency.getInstance("EUR"), amount);
}
/**
* Creates a US dollar money object.
* @param amount Amount in fractional dollars, so 1.5 for 1.50 USD
*/
public static Money usDollars(float amount) {
return Money.ofFractionalAmount(USD, amount);
}
/**
* Take two money instances and return the higher one.
*/
public static Money max(Money first, Money second) {
if (!first.currency.equals(second.currency)) {
throw new RuntimeException("Can't operate on %s and %s as the currencies are not equal.");
}
if (first.greaterThan(second)) {
return first;
} else {
return second;
}
}
/**
* Take a fractional amount of money, ie 1.5 and convert it to amount using the number of default
* fraction digits of the currency.
*/
public static Money ofFractionalAmount(@Nonnull Currency currency, float fractionalAmount) {
Objects.requireNonNull(currency);
var fractionDigits = currency.getDefaultFractionDigits();
int amount = IntUtils.round(fractionalAmount * Math.pow(10, fractionDigits));
return new Money(currency, amount);
}
/**
* Does this instance contain a non-zero amount.
*/
public boolean isPositive() {
return amount > 0f;
}
/**
* Is the mount in this instance zero.
*/
public boolean isZero() {
return amount == 0f;
}
@Override
public int compareTo(Money m) {
if (m.currency != currency) {
throw new RuntimeException("Can't compare " + m.currency + " to " + currency);
}
return amount - m.amount;
}
/**
* The amount in the major currency unit, so USD 3.10 is represented as 3.1 (not 310!).
*/
public BigDecimal fractionalAmount() {
int fractionDigits = currency.getDefaultFractionDigits();
var divisor = BigDecimal.valueOf(Math.pow(10, fractionDigits));
return new BigDecimal(amount)
.setScale(fractionDigits, RoundingMode.HALF_UP)
.divide(divisor, RoundingMode.HALF_UP);
}
/**
* The amount in the minor currency unit, so 1.50 EUR will be represented as 150.
*
* If the currency doesn't have a minor unit (like Japanese Yen) it is just the amount.
*/
public int minorUnitAmount() {
return amount;
}
public String localize(Locale loc) {
NumberFormat nf = NumberFormat.getCurrencyInstance(loc);
nf.setCurrency(currency);
nf.setMaximumFractionDigits(currency.getDefaultFractionDigits());
return nf.format(fractionalAmount());
}
@Override
public String toString() {
return localize(Locale.ENGLISH);
}
/**
* Subtract the money amount from this instance and return the result.
*/
public Money minus(Money other) {
return op(other, o -> new Money(currency, amount - o.amount));
}
/**
* Add another money amount to this instance and return it.
*/
public Money plus(Money other) {
return op(other, o -> new Money(currency, amount + o.amount));
}
/**
* Returns half this instance's amount
* Amounts in minor currency unit is rounded to nearest integer, so $0.99/2 becomes $0.50
*/
public Money half() {
return new Money(currency, IntUtils.round(amount / 2f));
}
/**
* Multiplies the amount with the multiplicator.
*/
public Money times(int multiplicator) {
return new Money(this.currency, amount * multiplicator);
}
/**
* Does this instance represent a larger amount than the one passed in?
*/
public boolean greaterThan(Money other) {
return booleanOp(other, amount > other.amount);
}
/**
* Does this instance represent a smaller amount than the one passed in?
*/
public boolean lessThan(Money other) {
return booleanOp(other, amount < other.amount);
}
/**
* The currency of this instance.
*/
public Currency currency() {
return currency;
}
private boolean booleanOp(Money other, boolean result) {
checkCurrencyOrThrow(other);
return result;
}
@Nonnull
private Money op(Money other, Function op) {
checkCurrencyOrThrow(other);
return op.apply(other);
}
private void checkCurrencyOrThrow(Money other) {
if (!currency.equals(other.currency)) {
throw new IllegalArgumentException(
"Cannot perform operations on %s and %s because they have unequal currency.".formatted(
this,
other
)
);
}
}
@Override
public boolean equals(Object obj) {
if (obj instanceof Money other) {
return other.amount == this.amount && other.currency == this.currency;
} else {
return false;
}
}
@Override
public int hashCode() {
return Objects.hash(currency, amount);
}
}