(IllegalArgumentException) Modify the Loan class in Listing 1 to throw IllegalArgumentExce...

(IllegalArgumentException) Modify the Loan class in Listing 1 to throw IllegalArgumentException if the loan amount, interest rate, or number of years is less than or equal to zero.

LISTING 1 Loan.java

1 public class Loan {
2 private double annualInterestRate;
3 private int numberOfYears;
4 private double loanAmount;
5 private java.util.Date loanDate;
6
7 /** Default constructor */
8 public Loan() {
9 this(2.5, 1, 1000);
10 }
11
12 /** Construct a loan with specified annual interest rate,
13 number of years, and loan amount
14 */
15 public Loan(double annualInterestRate, int numberOfYears,
16 double loanAmount) {
17 this.annualInterestRate = annualInterestRate;
18 this.numberOfYears = numberOfYears;
19 this.loanAmount = loanAmount;
20 loanDate = new java.util.Date();
21 }
22
23 /** Return annualInterestRate */
24 public double getAnnualInterestRate() {
25 return annualInterestRate;
26 }
27
28 /** Set a new annualInterestRate */
29 public void setAnnualInterestRate(double annualInterestRate) {
30 this.annualInterestRate = annualInterestRate;
31 }
32
33 /** Return numberOfYears */
34 public int getNumberOfYears() {
35 return numberOfYears;
36 }
37
38 /** Set a new numberOfYears */
39 public void setNumberOfYears(int numberOfYears) {
40 this.numberOfYears = numberOfYears;
41 }
42
43 /** Return loanAmount */
44 public double getLoanAmount() {
45 return loanAmount;
46 }
47
48 /** Set a new loanAmount */
49 public void setLoanAmount(double loanAmount) {
50 this.loanAmount = loanAmount;
51 }
52
53 /** Find monthly payment */
54 public double getMonthlyPayment() {
55 double monthlyInterestRate = annualInterestRate / 1200;
56 double monthlyPayment = loanAmount * monthlyInterestRate / (1 -
57 (1 / Math.pow(1 + monthlyInterestRate, numberOfYears * 12)));
58 return monthlyPayment;
59 }
60
61 /** Find total payment */
62 public double getTotalPayment() {
63 double totalPayment = getMonthlyPayment() * numberOfYears * 12;
64 return totalPayment;
65 }
66
67 /** Return loan date */
68 public java.util.Date getLoanDate() {
69 return loanDate;
70 }
71 }