Java tutorial
/* This file is part of Cyclos (www.cyclos.org). A project of the Social Trade Organisation (www.socialtrade.org). Cyclos is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. Cyclos is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Cyclos; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package nl.strohalm.cyclos.entities.accounts.loans; import java.io.Serializable; import java.math.BigDecimal; import java.math.MathContext; import java.util.Calendar; import nl.strohalm.cyclos.entities.accounts.transactions.TransferType; import nl.strohalm.cyclos.utils.Amount; import nl.strohalm.cyclos.utils.DateHelper; import org.apache.commons.lang.builder.EqualsBuilder; import org.apache.commons.lang.builder.HashCodeBuilder; /** * Contains parameters on TransferTypes to configure loans * @author luis */ public class LoanParameters implements Serializable, Cloneable { private static final long serialVersionUID = -2308200961589222771L; private Loan.Type type; private Integer repaymentDays; private TransferType repaymentType; private BigDecimal monthlyInterest; private TransferType monthlyInterestRepaymentType; private Amount grantFee; private TransferType grantFeeRepaymentType; private Amount expirationFee; private TransferType expirationFeeRepaymentType; private BigDecimal expirationDailyInterest; private TransferType expirationDailyInterestRepaymentType; private TransferType originalTransferType; /** * Calculates the grant fee to the given amount * @return 0 if no grant fee, the applied grant fee otherwise (ie: if grant fee = 3%, returns 30 for amount = 1000) */ public BigDecimal calculateGrantFee(final BigDecimal amount) { if (grantFee == null || grantFee.getValue() == null || amount.compareTo(BigDecimal.ZERO) != 1) { return BigDecimal.ZERO; } return grantFee.apply(amount); } /** * Calculates the total loan value for the given parameters */ public BigDecimal calculateLoanTotal(final BigDecimal amount, final int paymentCount, final Calendar grantDate, final Calendar firstExpirationDate, final MathContext mathContext) { final BigDecimal grantFee = calculateGrantFee(amount); final BigDecimal monthlyInterests = calculateMonthlyInterests(amount, paymentCount, grantDate, firstExpirationDate, mathContext); return amount.add(grantFee).add(monthlyInterests); } /** * Calculates the monthly interests for the given parameters * @return 0 if no monthly interests, or the applied interests otherwise (ie: if monthly interests = 1%, paymentCount = 1 and delay = 0, returns * 10 for amount = 1000) */ public BigDecimal calculateMonthlyInterests(final BigDecimal amount, final int paymentCount, Calendar grantDate, Calendar firstExpirationDate, final MathContext mathContext) { if (monthlyInterest == null || amount.compareTo(BigDecimal.ZERO) != 1 || paymentCount < 1) { return BigDecimal.ZERO; } // Calculate the delay final Calendar now = Calendar.getInstance(); grantDate = grantDate == null ? now : grantDate; firstExpirationDate = firstExpirationDate == null ? (Calendar) now.clone() : firstExpirationDate; final Calendar shouldBeFirstExpiration = (Calendar) grantDate.clone(); shouldBeFirstExpiration.add(Calendar.MONTH, 1); int delay = DateHelper.daysBetween(shouldBeFirstExpiration, firstExpirationDate); if (delay < 0) { delay = 0; } final BigDecimal grantFee = calculateGrantFee(amount); final BigDecimal baseAmount = amount.add(grantFee); final BigDecimal interests = monthlyInterest.divide(new BigDecimal(100), mathContext); final BigDecimal numerator = new BigDecimal( Math.pow(1 + interests.doubleValue(), paymentCount + delay / 30F)).multiply(interests); final BigDecimal denominator = new BigDecimal(Math.pow(1 + interests.doubleValue(), paymentCount) - 1); final BigDecimal paymentAmount = baseAmount.multiply(numerator).divide(denominator, mathContext); final BigDecimal totalAmount = paymentAmount.multiply(new BigDecimal(paymentCount)); return totalAmount.subtract(baseAmount); } /** * Calculates the expiration fee, if any, for the given loan payment parameters * @return 0 if no expiration fee, the applied expiration fee otherwise (ie: if expiration fee = 3%, returns 3 for amount = 100) */ public BigDecimal calculatePaymentExpirationFee(final BigDecimal amount, final int diff) { if (expirationFee != null && expirationFee.getValue() != null) { if (diff > 0) { return expirationFee.apply(amount); } } return BigDecimal.ZERO; } /** * Calculates the expiration daily interest, if any, for the given loan payment parameters * @return 0 if no interest, the applied interest otherwise (ie: if expiration daily interest fee = 1%, on 5 days after expiration, returns 1 for * amount = 100) */ public BigDecimal calculatePaymentExpirationInterest(final BigDecimal amount, final int diff, final MathContext mathContext) { if (expirationDailyInterest != null) { if (diff > 0) { return expirationDailyInterest.multiply(amount).multiply(new BigDecimal(diff)) .divide(new BigDecimal(100), mathContext); } } return BigDecimal.ZERO; } /** * Calculates the total amount of a loan payment on the given date */ public BigDecimal calculatePaymentTotal(final BigDecimal amount, final Calendar date, final Calendar expirationDate, final MathContext mathContext) { final int diff = DateHelper.daysBetween(date, expirationDate); return amount.add(calculatePaymentExpirationFee(amount, diff)) .add(calculatePaymentExpirationInterest(amount, diff, mathContext)); } @Override public LoanParameters clone() { try { return (LoanParameters) super.clone(); } catch (final CloneNotSupportedException e) { return null; } } @Override public boolean equals(final Object obj) { if (!(obj instanceof LoanParameters)) { return false; } final LoanParameters lp = (LoanParameters) obj; final EqualsBuilder eb = new EqualsBuilder(); eb.append(type, lp.type); eb.append(repaymentType, lp.repaymentType); eb.append(grantFee, lp.grantFee); eb.append(monthlyInterest, lp.monthlyInterest); eb.append(expirationFee, lp.expirationFee); eb.append(expirationDailyInterest, lp.expirationDailyInterest); eb.append(repaymentDays, lp.repaymentDays); return eb.isEquals(); } public BigDecimal getExpirationDailyInterest() { return expirationDailyInterest; } public Amount getExpirationDailyInterestAmount() { return expirationDailyInterest == null ? null : Amount.percentage(expirationDailyInterest); } public TransferType getExpirationDailyInterestRepaymentType() { return expirationDailyInterestRepaymentType; } public Amount getExpirationFee() { return expirationFee; } public TransferType getExpirationFeeRepaymentType() { return expirationFeeRepaymentType; } public Amount getGrantFee() { return grantFee; } public TransferType getGrantFeeRepaymentType() { return grantFeeRepaymentType; } public BigDecimal getMonthlyInterest() { return monthlyInterest; } public Amount getMonthlyInterestAmount() { return monthlyInterest == null ? null : Amount.percentage(monthlyInterest); } public TransferType getMonthlyInterestRepaymentType() { return monthlyInterestRepaymentType; } public TransferType getOriginalTransferType() { return originalTransferType; } public Integer getRepaymentDays() { return repaymentDays; } public TransferType getRepaymentType() { return repaymentType; } public Loan.Type getType() { return type; } @Override public int hashCode() { final HashCodeBuilder hcb = new HashCodeBuilder(); hcb.append(type); hcb.append(repaymentType); hcb.append(grantFee); hcb.append(monthlyInterest); hcb.append(expirationFee); hcb.append(expirationDailyInterest); hcb.append(repaymentDays); return hcb.toHashCode(); } public void setExpirationDailyInterest(final BigDecimal expirationDailyInterests) { expirationDailyInterest = expirationDailyInterests; } public void setExpirationDailyInterestRepaymentType(final TransferType expirationDailyInterestRepaymentType) { this.expirationDailyInterestRepaymentType = expirationDailyInterestRepaymentType; } public void setExpirationFee(final Amount expirationFee) { this.expirationFee = expirationFee; } public void setExpirationFeeRepaymentType(final TransferType expirationFeeRepaymentType) { this.expirationFeeRepaymentType = expirationFeeRepaymentType; } public void setGrantFee(final Amount grantFee) { this.grantFee = grantFee; } public void setGrantFeeRepaymentType(final TransferType grantFeeRepaymentType) { this.grantFeeRepaymentType = grantFeeRepaymentType; } public void setMonthlyInterest(final BigDecimal monthlyInterests) { monthlyInterest = monthlyInterests; } public void setMonthlyInterestRepaymentType(final TransferType monthlyInterestRepaymentType) { this.monthlyInterestRepaymentType = monthlyInterestRepaymentType; } public void setOriginalTransferType(final TransferType originalTransferType) { this.originalTransferType = originalTransferType; } public void setRepaymentDays(final Integer repaymentDays) { this.repaymentDays = repaymentDays; } public void setRepaymentType(final TransferType repaymentType) { this.repaymentType = repaymentType; } public void setType(final Loan.Type type) { this.type = type; } }