@Test
public void testGetPaymentsAmortizedWithOverPayment() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(ofUSD(10000));
amAttrs.setInterestRateAsPercent(3.);
amAttrs.setInterestOnly(false);
amAttrs.setRegularPayment(ofUSD(400));
amAttrs.setPaymentFrequency(TimePeriod.SemiMonthly.getPeriodsPerYear());
int termInMonths = 24;
amAttrs.setTermInMonths(termInMonths);
amAttrs.setAmortizationPeriodInMonths(24);
amAttrs.setCompoundingPeriodsPerYear(2);
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
assertEquals(
"Amortized payment count",
amAttrs.getPaymentFrequency() * termInMonths / 12,
schedule.size());
MonetaryAmount interestTotal =
schedule.stream().map(payment -> payment.getInterest()).reduce((a, b) -> a.add(b)).get();
assertEquals("Amortized Interest total", ofUSD(164.81), interestTotal);
}
@Test
public void testGetPaymentsAmortizedFully() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
MonetaryAmount loanAmount = ofUSD(10000);
amAttrs.setLoanAmount(loanAmount);
amAttrs.setInterestRateAsPercent(7.);
amAttrs.setInterestOnly(false);
amAttrs.setPaymentFrequency(TimePeriod.Monthly.getPeriodsPerYear());
int termInMonths = 12;
amAttrs.setTermInMonths(termInMonths);
amAttrs.setAmortizationPeriodInMonths(12);
amAttrs.setCompoundingPeriodsPerYear(2);
amAttrs.setRegularPayment(AmortizationCalculator.getPeriodicPayment(amAttrs));
List<ScheduledPayment> schedule = AmortizationCalculator.generateSchedule(amAttrs);
MonetaryAmount interestTotal =
schedule.stream().map(payment -> payment.getInterest()).reduce((a, b) -> a.add(b)).get();
assertEquals("Amortized Interest total", ofUSD(377.67), interestTotal);
MonetaryAmount principalTotal =
schedule.stream().map(payment -> payment.getPrincipal()).reduce((a, b) -> a.add(b)).get();
assertEquals("Amortized Principal fully paid", loanAmount, principalTotal);
}
@Test
public void testGetPeriodicPaymentAmortizedMonthlyCompoundPeriod() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000.multiply(2));
amAttrs.setInterestRateAsPercent(12.);
amAttrs.setCompoundingPeriodsPerYear(12);
amAttrs.setPaymentFrequency(12);
MonetaryAmount result = AmortizationCalculator.getPeriodicPayment(amAttrs);
MonetaryAmount expectedResult = ofUSD(1053.23);
assertEquals("Monthly amortized payment compounded monthly", expectedResult, result);
}
@Test
public void testGetPeriodicPaymentCompoundSemiPaymentSemiAnnually() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000.divide(5));
amAttrs.setInterestRateAsPercent(10.);
amAttrs.setCompoundingPeriodsPerYear(TimePeriod.SemiAnnually.getPeriodsPerYear());
amAttrs.setAmortizationPeriodInMonths(12);
amAttrs.setPaymentFrequency(TimePeriod.SemiAnnually.getPeriodsPerYear());
MonetaryAmount result = AmortizationCalculator.getPeriodicPayment(amAttrs);
MonetaryAmount expectedResult = ofUSD(5378.05);
assertEquals("Amortized, compounded semi-annual, payment semimonthly", expectedResult, result);
}
private AmortizationAttributes generateAmortizationAttributesObjectTemplate() {
AmortizationAttributes amAttrs = new AmortizationAttributes();
amAttrs.setLoanAmount(USD50000);
amAttrs.setRegularPayment(USD50000.divide(100));
amAttrs.setStartDate(LocalDate.of(2015, Month.DECEMBER, 28));
amAttrs.setAdjustmentDate(LocalDate.of(2016, Month.JANUARY, 1));
amAttrs.setTermInMonths(24);
amAttrs.setInterestOnly(false);
amAttrs.setAmortizationPeriodInMonths(300);
amAttrs.setCompoundingPeriodsPerYear(2);
amAttrs.setPaymentFrequency(12);
amAttrs.setInterestRateAsPercent(12.);
return amAttrs;
}
@Test
public void testGetPeriodInterest_Amortized() {
AmortizationAttributes amAttrs = generateAmortizationAttributesObjectTemplate();
amAttrs.setLoanAmount(USD50000.multiply(2));
amAttrs.setInterestRateAsPercent(12.);
amAttrs.setCompoundingPeriodsPerYear(2);
amAttrs.setPaymentFrequency(12);
List<ScheduledPayment> generatedSchedule = AmortizationCalculator.generateSchedule(amAttrs);
generatedSchedule
.stream()
.forEachOrdered(
p -> {
MonetaryAmount periodInterest = AmortizationCalculator.getPeriodInterest(amAttrs);
assertEquals(
"Monthly amortized payment interest matches peirod interest",
p.getInterest(),
periodInterest);
amAttrs.setLoanAmount(p.getBalance());
});
}