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 com.gst.portfolio.savings.domain.interest; import java.math.BigDecimal; import java.math.MathContext; import com.gst.infrastructure.core.domain.LocalDateInterval; import com.gst.organisation.monetary.domain.Money; import com.gst.organisation.monetary.domain.MoneyHelper; import org.joda.time.LocalDate; public class EndOfDayBalance { private final LocalDate date; private final Money openingBalance; private final Money endOfDayBalance; private final int numberOfDays; public static EndOfDayBalance from(final LocalDate date, final Money openingBalance, final Money endOfDayBalance, final int numberOfDays) { return new EndOfDayBalance(date, openingBalance, endOfDayBalance, numberOfDays); } public EndOfDayBalance(final LocalDate date, final Money openingBalance, final Money endOfDayBalance, final int numberOfDays) { this.date = date; this.openingBalance = openingBalance; this.endOfDayBalance = endOfDayBalance; this.numberOfDays = numberOfDays; } public LocalDate date() { return this.date; } public Money closingBalance() { return this.endOfDayBalance; } public BigDecimal cumulativeBalance(final BigDecimal interestToCompound) { final BigDecimal daysAsBigDecimal = BigDecimal.valueOf(this.numberOfDays); final BigDecimal realBalanceForInterestCalculation = this.endOfDayBalance.getAmount() .add(interestToCompound); return realBalanceForInterestCalculation.multiply(daysAsBigDecimal, MathContext.DECIMAL64).setScale(9, MoneyHelper.getRoundingMode()); } public BigDecimal calculateInterestOnBalance(final BigDecimal interestToCompound, final BigDecimal interestRateAsFraction, final long daysInYear, final BigDecimal minBalanceForInterestCalculation, final BigDecimal overdraftInterestRateAsFraction, final BigDecimal minOverdraftForInterestCalculation) { BigDecimal interest = BigDecimal.ZERO.setScale(9, MoneyHelper.getRoundingMode()); final BigDecimal realBalanceForInterestCalculation = this.endOfDayBalance.getAmount() .add(interestToCompound); if (realBalanceForInterestCalculation.compareTo(BigDecimal.ZERO) >= 0) { if (realBalanceForInterestCalculation.compareTo(minBalanceForInterestCalculation) >= 0) { final BigDecimal multiplicand = BigDecimal.ONE.divide(BigDecimal.valueOf(daysInYear), MathContext.DECIMAL64); final BigDecimal dailyInterestRate = interestRateAsFraction.multiply(multiplicand, MathContext.DECIMAL64); final BigDecimal periodicInterestRate = dailyInterestRate .multiply(BigDecimal.valueOf(this.numberOfDays), MathContext.DECIMAL64); interest = realBalanceForInterestCalculation.multiply(periodicInterestRate, MathContext.DECIMAL64) .setScale(9, MoneyHelper.getRoundingMode()); } } else { if (realBalanceForInterestCalculation.compareTo(minOverdraftForInterestCalculation.negate()) < 0) { final BigDecimal multiplicand = BigDecimal.ONE.divide(BigDecimal.valueOf(daysInYear), MathContext.DECIMAL64); final BigDecimal dailyInterestRate = overdraftInterestRateAsFraction.multiply(multiplicand, MathContext.DECIMAL64); final BigDecimal periodicInterestRate = dailyInterestRate .multiply(BigDecimal.valueOf(this.numberOfDays), MathContext.DECIMAL64); interest = realBalanceForInterestCalculation.multiply(periodicInterestRate, MathContext.DECIMAL64) .setScale(9, MoneyHelper.getRoundingMode()); } } return interest; } /** * Future Value (FV) = PV x (1+r)^n * * Interest = FV - PV PV = Principal or the Account Balance r = rate per * compounding period (so for daily, r = nominalInterestRateAsFraction x * 1/365 n = number of periods rate is compounded */ public BigDecimal calculateInterestOnBalanceAndInterest(final BigDecimal interestToCompound, final BigDecimal interestRateAsFraction, final long daysInYear, final BigDecimal minBalanceForInterestCalculation, final BigDecimal overdraftInterestRateAsFraction, final BigDecimal minOverdraftForInterestCalculation) { final BigDecimal multiplicand = BigDecimal.ONE.divide(BigDecimal.valueOf(daysInYear), MathContext.DECIMAL64); final BigDecimal presentValue = this.endOfDayBalance.getAmount().add(interestToCompound); BigDecimal futureValue = presentValue.setScale(9, MoneyHelper.getRoundingMode()); if (presentValue.compareTo(BigDecimal.ZERO) >= 0) { if (presentValue.compareTo(minBalanceForInterestCalculation) >= 0) { final BigDecimal r = interestRateAsFraction.multiply(multiplicand); final BigDecimal interestRateForCompoundingPeriodPlusOne = BigDecimal.ONE.add(r); final double interestRateForCompoundingPeriodPowered = Math.pow( interestRateForCompoundingPeriodPlusOne.doubleValue(), Integer.valueOf(this.numberOfDays).doubleValue()); futureValue = presentValue.multiply(BigDecimal.valueOf(interestRateForCompoundingPeriodPowered), MathContext.DECIMAL64).setScale(9, MoneyHelper.getRoundingMode()); } } else { if (presentValue.compareTo(minOverdraftForInterestCalculation.negate()) < 0) { final BigDecimal r = overdraftInterestRateAsFraction.multiply(multiplicand); final BigDecimal interestRateForCompoundingPeriodPlusOne = BigDecimal.ONE.add(r); final double interestRateForCompoundingPeriodPowered = Math.pow( interestRateForCompoundingPeriodPlusOne.doubleValue(), Integer.valueOf(this.numberOfDays).doubleValue()); futureValue = presentValue.multiply(BigDecimal.valueOf(interestRateForCompoundingPeriodPowered), MathContext.DECIMAL64).setScale(9, MoneyHelper.getRoundingMode()); } } return futureValue.subtract(presentValue); } /** * @param compoundingPeriodInterval * @param upToInterestCalculationDate * : For calculating maturity details in advance * upToInterestCalculationDate will be maturity date else it will * be DateUtils.getLocalDateOfTenant(). * @return */ public EndOfDayBalance upTo(final LocalDateInterval compoundingPeriodInterval, final LocalDate upToInterestCalculationDate) { Money startingBalance = this.openingBalance; LocalDate balanceStartDate = this.date; LocalDate oldBalanceEndDate = this.date.plusDays(this.numberOfDays - 1); int daysOfBalance = this.numberOfDays; if (this.date.isBefore(compoundingPeriodInterval.startDate())) { balanceStartDate = compoundingPeriodInterval.startDate(); startingBalance = this.endOfDayBalance; final LocalDateInterval balancePeriodInterval = LocalDateInterval.create(balanceStartDate, oldBalanceEndDate); daysOfBalance = balancePeriodInterval.daysInPeriodInclusiveOfEndDate(); } LocalDate balanceEndDate = balanceStartDate.plusDays(daysOfBalance - 1); if (balanceEndDate.isAfter(compoundingPeriodInterval.endDate())) { balanceEndDate = compoundingPeriodInterval.endDate(); final LocalDateInterval balancePeriodInterval = LocalDateInterval.create(balanceStartDate, balanceEndDate); daysOfBalance = balancePeriodInterval.daysInPeriodInclusiveOfEndDate(); } if (balanceEndDate.isAfter(upToInterestCalculationDate)) { balanceEndDate = upToInterestCalculationDate; final LocalDateInterval balancePeriodInterval = LocalDateInterval.create(balanceStartDate, balanceEndDate); daysOfBalance = balancePeriodInterval.daysInPeriodInclusiveOfEndDate(); } return new EndOfDayBalance(balanceStartDate, startingBalance, this.endOfDayBalance, daysOfBalance); } public boolean contains(final LocalDateInterval compoundingPeriodInterval) { final LocalDate balanceUpToDate = this.date.plusDays(this.numberOfDays - 1); final LocalDateInterval balanceInterval = LocalDateInterval.create(this.date, balanceUpToDate); return balanceInterval.containsPortionOf(compoundingPeriodInterval); } public Integer getNumberOfDays() { return Integer.valueOf(this.numberOfDays); } }