Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.apache.fineract.portfolio.loanaccount.loanschedule.domain; import java.math.BigDecimal; import java.math.MathContext; import java.util.Collection; import java.util.HashMap; import java.util.Map; import java.util.TreeMap; import org.apache.fineract.infrastructure.core.service.DateUtils; import org.apache.fineract.organisation.monetary.domain.Money; import org.apache.fineract.portfolio.loanaccount.data.LoanTermVariationsData; import org.apache.fineract.portfolio.loanproduct.domain.AmortizationMethod; import org.joda.time.Days; import org.joda.time.LocalDate; /** * <p> * Declining balance can be amortized (see {@link AmortizationMethod}) in two * ways at present: * <ol> * <li>Equal principal payments</li> * <li>Equal installment payments</li> * </ol> * </p> * * <p> * When amortized using <i>equal principal payments</i>, the <b>principal * component</b> of each installment is fixed and <b>interest due</b> is * calculated from the <b>outstanding principal balance</b> resulting in a * different <b>total payment due</b> for each installment. * </p> * * <p> * When amortized using <i>equal installments</i>, the <b>total payment due</b> * for each installment is fixed and is calculated using the excel like * <code>pmt</code> function. The <b>interest due</b> is calculated from the * <b>outstanding principal balance</b> which results in a <b>principal * component</b> that is <b>total payment due</b> minus <b>interest due</b>. * </p> */ public class DecliningBalanceInterestLoanScheduleGenerator extends AbstractLoanScheduleGenerator { @Override public PrincipalInterest calculatePrincipalInterestComponentsForPeriod( final PaymentPeriodsInOneYearCalculator calculator, final double interestCalculationGraceOnRepaymentPeriodFraction, final Money totalCumulativePrincipal, @SuppressWarnings("unused") final Money totalCumulativeInterest, @SuppressWarnings("unused") final Money totalInterestDueForLoan, final Money cumulatingInterestPaymentDueToGrace, final Money outstandingBalance, final LoanApplicationTerms loanApplicationTerms, final int periodNumber, final MathContext mc, final TreeMap<LocalDate, Money> principalVariation, final Map<LocalDate, Money> compoundingMap, final LocalDate periodStartDate, final LocalDate periodEndDate, final Collection<LoanTermVariationsData> termVariations) { LocalDate interestStartDate = periodStartDate; Money interestForThisInstallment = totalCumulativePrincipal.zero(); Money compoundedMoney = totalCumulativePrincipal.zero(); Money compoundedInterest = totalCumulativePrincipal.zero(); Money balanceForInterestCalculation = outstandingBalance; Money cumulatingInterestDueToGrace = cumulatingInterestPaymentDueToGrace; Map<LocalDate, BigDecimal> interestRates = new HashMap<>(termVariations.size()); for (LoanTermVariationsData loanTermVariation : termVariations) { if (loanTermVariation.getTermVariationType().isInterestRateVariation() && loanTermVariation.isApplicable(periodStartDate, periodEndDate)) { LocalDate fromDate = loanTermVariation.getTermApplicableFrom(); if (fromDate == null) { fromDate = periodStartDate; } interestRates.put(fromDate, loanTermVariation.getDecimalValue()); if (!principalVariation.containsKey(fromDate)) { principalVariation.put(fromDate, balanceForInterestCalculation.zero()); } } } if (principalVariation != null) { // identifies rest date after current date for reducing all // compounding // values LocalDate compoundingEndDate = principalVariation.ceilingKey(DateUtils.getLocalDateOfTenant()); if (compoundingEndDate == null) { compoundingEndDate = DateUtils.getLocalDateOfTenant(); } for (Map.Entry<LocalDate, Money> principal : principalVariation.entrySet()) { if (!principal.getKey().isAfter(periodEndDate)) { int interestForDays = Days.daysBetween(interestStartDate, principal.getKey()).getDays(); if (interestForDays > 0) { final PrincipalInterest result = loanApplicationTerms.calculateTotalInterestForPeriod( calculator, interestCalculationGraceOnRepaymentPeriodFraction, periodNumber, mc, cumulatingInterestDueToGrace, balanceForInterestCalculation, interestStartDate, principal.getKey()); interestForThisInstallment = interestForThisInstallment.plus(result.interest()); cumulatingInterestDueToGrace = result.interestPaymentDueToGrace(); interestStartDate = principal.getKey(); } Money compoundFee = totalCumulativePrincipal.zero(); if (compoundingMap.containsKey(principal.getKey())) { Money interestToBeCompounded = totalCumulativePrincipal.zero(); // for interest compounding if (loanApplicationTerms.getInterestRecalculationCompoundingMethod() .isInterestCompoundingEnabled()) { interestToBeCompounded = interestForThisInstallment.minus(compoundedInterest); balanceForInterestCalculation = balanceForInterestCalculation .plus(interestToBeCompounded); compoundedInterest = interestForThisInstallment; } // fee compounding will be done after calculation compoundFee = compoundingMap.get(principal.getKey()); compoundedMoney = compoundedMoney.plus(interestToBeCompounded).plus(compoundFee); } balanceForInterestCalculation = balanceForInterestCalculation.plus(principal.getValue()) .plus(compoundFee); if (interestRates.containsKey(principal.getKey())) { loanApplicationTerms.updateAnnualNominalInterestRate(interestRates.get(principal.getKey())); } } } if (!periodEndDate.isBefore(compoundingEndDate)) { balanceForInterestCalculation = balanceForInterestCalculation.minus(compoundedMoney); compoundingMap.clear(); } else if (compoundedMoney.isGreaterThanZero()) { compoundingMap.put(periodEndDate, compoundedMoney); compoundingMap.put(compoundingEndDate, compoundedMoney.negated()); clearMapDetails(periodEndDate, compoundingMap); } } final PrincipalInterest result = loanApplicationTerms.calculateTotalInterestForPeriod(calculator, interestCalculationGraceOnRepaymentPeriodFraction, periodNumber, mc, cumulatingInterestDueToGrace, balanceForInterestCalculation, interestStartDate, periodEndDate); interestForThisInstallment = interestForThisInstallment.plus(result.interest()); cumulatingInterestDueToGrace = result.interestPaymentDueToGrace(); Money interestForPeriod = interestForThisInstallment; if (interestForPeriod.isGreaterThanZero()) { interestForPeriod = interestForPeriod.minus(cumulatingInterestPaymentDueToGrace); } else { interestForPeriod = cumulatingInterestDueToGrace.minus(cumulatingInterestPaymentDueToGrace); } Money principalForThisInstallment = loanApplicationTerms.calculateTotalPrincipalForPeriod(calculator, outstandingBalance, periodNumber, mc, interestForPeriod); // update cumulative fields for principal & interest final Money interestBroughtFowardDueToGrace = cumulatingInterestDueToGrace; final Money totalCumulativePrincipalToDate = totalCumulativePrincipal.plus(principalForThisInstallment); // adjust if needed principalForThisInstallment = loanApplicationTerms.adjustPrincipalIfLastRepaymentPeriod( principalForThisInstallment, totalCumulativePrincipalToDate, periodNumber); return new PrincipalInterest(principalForThisInstallment, interestForThisInstallment, interestBroughtFowardDueToGrace); } }