第5周作业-贷款计算器程序

import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.border.TitledBorder;public class LoanCalculator  extends JFrame {private JTextField jtfAnnualInterestRate = new JTextField();private JTextField jtfNumberofYears = new JTextField();private JTextField jtfLoanAmount = new JTextField();private JTextField jtfMonthlyPayment = new JTextField();private JTextField jtfTotalPayment = new JTextField();private JButton jbtComputeLoan = new JButton("Compute Payment");public LoanCalculator() {JPanel p1 = new JPanel(new GridLayout(5,2));p1.add(new JLabel("Annual Interest Rate"));p1.add(jtfAnnualInterestRate);p1.add(new JLabel("Number of Years"));p1.add(jtfNumberofYears);p1.add(new JLabel("Loan Amount"));p1.add(jtfLoanAmount);p1.add(new JLabel("Monthly Payment"));p1.add(jtfMonthlyPayment);p1.add(new JLabel("Total Payment"));p1.add(jtfTotalPayment);p1.setBorder(new TitledBorder("Enter loan amout,interest rate,and year"));JPanel p2 = new JPanel(new FlowLayout(FlowLayout.RIGHT));p2.add(jbtComputeLoan);add(p1,BorderLayout.CENTER);add(p2,BorderLayout.SOUTH);jbtComputeLoan.addActionListener(new ButtonListener());}private class ButtonListener implements ActionListener {public void actionPerformed(ActionEvent e ) {double interest = Double.parseDouble(jtfAnnualInterestRate.getText());int year =Integer.parseInt(jtfNumberofYears.getText());Double .parseDouble(jtfLoanAmount.getText());Loan loan = new Loan (interest,year,loanAmount);//Loan loan = new Loan(interest,year,loanAmount);jtfMonthlyPayment.setText(String.format("%.2f",loan.getMonthlyPayment()));jtfTotalPayment.setText(String.format("%.2f",loan.getTotalPayment()));}}  public static void main(String[] args){   LoanCalculator frame = new LoanCalculator();   frame.pack();   frame.setTitle("LoanCaculator");   frame.setLocationRelativeTo(null);   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   frame.setVisible(true);}}