"loanAmount", "loanTypeBox", "paymentList"
Для этих трех, Вы должны закомментировать эти три строки, потому что вы уже объявили их, требуется только назначение;
//JTextField loanAmount = new JTextField(10); // loanAmount: Already declared, only assignment needed
loanAmount = new JTextField(10);
//JComboBox loanTypeBox = new JComboBox(items); // loanTypeBox: Already declared, only assignment needed
loanTypeBox = new JComboBox(items);
//JTextArea paymentList = new JTextArea("", 17, 27);// paymentList: Already declared, only assignment needed
paymentList = new JTextArea("", 17, 27);
Вот обновленный код;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.text.DecimalFormat;
public class MortgageGui extends JFrame implements ActionListener {
// Set two-places for decimal format
DecimalFormat twoPlaces = new DecimalFormat("$0.00");
// Declare variable for calculation
Double loanAmt;
double interestRate;
double monthlyPayment;
int payment;
String amount;
JTextField loanAmount;
JComboBox loanTypeBox;
JLabel paymentOutput;
JTextArea paymentList;
// Build arrays for mortgages
double[] mortgage1 = { 7.0, 5.35, 0.0 }; // (years, interest, monthly
// payment)
double[] mortgage2 = { 15.0, 5.5, 0.0 }; // (years, interest, monthly
// payment)
double[] mortgage3 = { 30.0, 5.75, 0.0 }; // (years, interest, monthly
// payment)
public MortgageGui() {
super("Mortgage Calculator");
setLookAndFeel();
setSize(350, 500);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Loan Amount Panel
JPanel loanAmtPanel = new JPanel();
JLabel loanAmtLabel = new JLabel("Loan Amount: ", JLabel.LEFT);
// JTextField loanAmount = new JTextField(10); // loanAmount: Already declared, only assignment needed
loanAmount = new JTextField(10);
loanAmtPanel.add(loanAmtLabel);
loanAmtPanel.add(loanAmount);
// Loan Type Panel
JPanel loanTypePanel = new JPanel();
JLabel loanTypeLabel = new JLabel("Loan Type: ", JLabel.LEFT);
String[] items = { "7 years at 5.35%", "15 years at 5.5%",
"30 years at 5.75%" };
// JComboBox loanTypeBox = new JComboBox(items); // loanTypeBox: Already declared, only assignment needed
loanTypeBox = new JComboBox(items);
loanTypePanel.add(loanTypeLabel);
loanTypePanel.add(loanTypeBox);
// Calculate Button Panel
JPanel calculatePanel = new JPanel();
JButton calcButton = new JButton("Calculate Paytment");
calcButton.addActionListener(this);
calculatePanel.add(calcButton);
// Monthly Payment Panel
JPanel paymentPanel = new JPanel();
JLabel paymentLabel = new JLabel("Monthly Payment: ", JLabel.LEFT);
JLabel paymentOutput = new JLabel("Calculated Payment");
paymentPanel.add(paymentLabel);
paymentPanel.add(paymentOutput);
// View Payments Panel
JPanel viewPayments = new JPanel();
// JTextArea paymentList = new JTextArea("", 17, 27); // paymentList: Already declared, only assignment needed
paymentList = new JTextArea("", 17, 27);
paymentList.setEditable(false);
paymentList.setLineWrap(true);
viewPayments.add(paymentList);
// Add panels to win Panel
JPanel win = new JPanel();
BoxLayout box = new BoxLayout(win, BoxLayout.Y_AXIS);
win.setLayout(box);
win.add(loanAmtPanel);
win.add(loanTypePanel);
win.add(calculatePanel);
win.add(paymentPanel);
win.add(viewPayments);
add(win);
// Make window visible
setVisible(true);
}
private void setLookAndFeel() {
try {
UIManager
.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Exception exc) {
// ignore
}
}
public void actionPerformed(ActionEvent e) {
// Clear payment list
paymentList.setText("");
// Get loan amount from textfield
String amount = loanAmount.getText();
loanAmt = Double.valueOf(amount).doubleValue();
// Find which mortgate array to use from combobox
Object obj = loanTypeBox.getSelectedItem();
String loanSelected = obj.toString();
// Run the calculation based on the mortgage arrays
// 7-year loan
if (loanSelected.equals("7 years at 5.35%")) {
// Calculate payment, interest, and remaining
mortgage1[2] = (loanAmt + (loanAmt * (mortgage1[1] / 100)))
/ (mortgage1[0] * 12);
double interest1 = (loanAmt * (mortgage1[1] / 100)) / 84;
double amountRemaining1 = loanAmt
+ (loanAmt * (mortgage1[1] / 100));
// Loop through payments
for (int payment = 1; payment <= 84; payment++) {
// Deduct one payment from the balance
amountRemaining1 = amountRemaining1 - mortgage1[2];
// Write payment to textArea
paymentList.append("Payment " + payment + ": $"
+ twoPlaces.format(mortgage1[2]) + " / "
+ "Interest: $" + twoPlaces.format(interest1) + " / "
+ "Remaining: $" + twoPlaces.format(amountRemaining1)
+ "\n");
}
} else {
// 15-year loan
if (loanSelected.equals("15 years at 5.5%")) {
// Calculate payment, interest, and remaining
mortgage2[2] = (loanAmt + (loanAmt * (mortgage2[1] / 100)))
/ (mortgage2[0] * 12);
double interest2 = (loanAmt * (mortgage2[1] / 100)) / 180;
double amountRemaining2 = loanAmt
+ (loanAmt * (mortgage2[1] / 100));
// Loop through payments
for (int payment = 1; payment <= 180; payment++) {
// Deduct one payment from the balance
amountRemaining2 = amountRemaining2 - mortgage2[2];
// Write payment to textArea
paymentList.append("Payment " + payment + ": $"
+ twoPlaces.format(mortgage2[2]) + " / "
+ "Interest: $" + twoPlaces.format(interest2)
+ " / " + "Remaining: $"
+ twoPlaces.format(amountRemaining2) + "\n");
}
} else {
// 30-year loan
// Calculate payment, interest, and remaining
mortgage3[2] = (loanAmt + (loanAmt * (mortgage3[1] / 100)))
/ (mortgage3[0] * 12);
double interest3 = (loanAmt * (mortgage3[1] / 100)) / 360;
double amountRemaining3 = loanAmt
+ (loanAmt * (mortgage3[1] / 100));
// Loop through payments
for (int payment = 1; payment <= 360; payment++) {
// Deduct one payment from the balance
amountRemaining3 = amountRemaining3 - mortgage3[2];
// Write payment to textArea
paymentList.append("Payment " + payment + ": $"
+ twoPlaces.format(mortgage3[2]) + " / "
+ "Interest: $" + twoPlaces.format(interest3)
+ " / " + "Remaining: $"
+ twoPlaces.format(amountRemaining3) + "\n");
}
}
}
}
public static void main(String[] arguments) {
MortgageGui calc = new MortgageGui();
}
}
И вывод такой, как показано ниже, без каких-либо ошибок на консоли;
