Loan Monthly Payment Calculator

package myMortgagePackage;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;



/**
 *
 * @author Zau
 */
public class MortgageCalculatorFrm extends javax.swing.JFrame {

    /**
     * Creates new form MortgageCalculatorFrm
     */
    public MortgageCalculatorFrm() {
        initComponents();
       
        //Step 1: Register button with anonymous actionListener class
        jbtnComputeMonthlyPayment.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent ae) {
              //Read data from user
               
                double principle = Double.parseDouble(jtxtLoanAmount.getText());
                double interestRate = Double.parseDouble(jtxtAPR.getText());
                //int numberOfYear = Int.parseInt(jtxtYear.getText());
                int numberOfYear = Integer.parseInt(jtxtYear.getText());
               
                //Convert interest rate into decimal
                interestRate /= 100.0;
               
                //Monthly interest rate is the yearly rate divided by 12
                double monthlyRate = interestRate/12.0;
               
                //The lenght of the term in months is
                //the number of years times 12
                int termInMonths = numberOfYear * 12;
               
                //Calculate the monthly payment
                double monthlyPayment = (principle*monthlyRate) / (1-Math.pow(1+monthlyRate, -termInMonths));
           
                //Total interest
                double totalInterest = ((monthlyPayment * termInMonths) - principle);
                NumberFormat formatter = NumberFormat.getCurrencyInstance();
                jtxtMonthlyPayment.setText(formatter.format(monthlyPayment));
                jtxtTotalInterest.setText(formatter.format(totalInterest));
            }
        });
       
        //add action event to clear the button
        jbtnClear.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent ae) {
                jtxtLoanAmount.setText("");
                jtxtAPR.setText("");
                jtxtYear.setText("");
                jtxtMonthlyPayment.setText("");
                jtxtTotalInterest.setText("");
            }
        });
    }