Mortgage Program in GUI format

Question

I am having trouble with writing a mortgage program. The program should allow the users to choose the format inwhich they input their mortgage information. It is to then display his mortgage payment, monthly interest, and balance over the duration of the loan. I thought I had everything right, after serveral error corrections, I get the below listed errors. I understand what they are saying is wrong with the program, but I lack the ability ot decipher how to fix it. Any informaton would be greatly appreciated.
errors:
H:\My Documents\Java Training\ShellyJava\Chapter.10\week4.java:333: illegal start of expression
private static void createAndShowGUI() {
^
H:\My Documents\Java Training\ShellyJava\Chapter.10\week4.java:388: ';' expected
^
2 errors
Code;
import java.util.Set;
import java.util.HashSet;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;
import java.text.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.Graphics.*;
import java.lang.Math.*;
import java.util.*;
import java.text.NumberFormat;
import java.io.*;
import java.awt.event.*;
import javax.swing.*;
public class week4 extends JPanel {
//Defines Labels
private JLabel Amount_Label;
private JLabel Rate_Label;
private JLabel Term_Label;
private JLabel Payments_Label;
//Defines Strings for Labels
private static String Amount_String = "Loan Amount: ";
private static String Rate_String = "Percentage Rate: ";
private static String Term_String = "Term (In Years): ";
private static String Payments_String = "Monthly Payment: ";
//Defines Text Fields
private JTextField Amount_Field;
private JTextField Rate_Field;
private JTextField Term_Field;
private JTextField Payments_Field;
//Defines number Formats
private NumberFormat Loan_Format;
private NumberFormat Rate_Format;
private DecimalFormat Term_Format;
private DecimalFormat Payments_Format;
private Verifier verifier = new Verifier();
//Defines Buttons
private JButton MortgageCalc = new JButton("Calculate");
     private JButton Clear = new JButton("Clear");
     private JButton Exit = new JButton("Good-bye");
     //Defines Combo Boxes
     private JComboBox Rate_Box;
     private JComboBox Term_Box;
public week4() {
super(new BorderLayout());
setUpFormats();
//Creates the labels.
Amount_Label = new JLabel(Amount_String);
Rate_Label = new JLabel(Rate_String);
Term_Label = new JLabel(Term_String);
Payments_Label = new JLabel(Payments_String);
//Creates the text fields
Amount_Field = new JTextField(Loan_Format.format(0), 12);
Amount_Field.setInputVerifier(verifier);
Rate_Field = new JTextField(Rate_Format.format(0), 12);
Rate_Field.setInputVerifier(verifier);
Term_Field = new JTextField(Term_Format.format(0), 12);
Term_Field.setInputVerifier(verifier);
Payments_Field = new JTextField(Payments_Format.format(0), 12);
Payments_Field.setInputVerifier(verifier);
Payments_Field.setEditable(false);
//Creates Buttons
MortgageCalc = new JButton("Calculate");
Clear = new JButton("Clear");
Exit = new JButton("Exit");
//Creates the Combo Boxes
Rate_Box = new JComboBox ();
     Rate_Box.addItem("5.35%");
     Rate_Box.addItem("5.50%");
     Rate_Box.addItem("5.75%");
     Rate_Box.addItem("Select One");
     add(Rate_Box);
Term_Box = new JComboBox ();
     Term_box.addItem("7 years");
     Term_box.addItem("15 years");
     Term_box.addItem("30 years");
     Term_box.addItem("Select One");
     add(Term_Box);
//Defines Listner
Amount_Field.addActionListener(verifier);
Rate_Field.addActionListener(verifier);
Term_Field.addActionListener(verifier);
Rate_Box.addActionListener(verifier);
Term_box.addActionListener(verifier);
MortgageCalc.addActionListener(verifier);
Clear.addActionListner(verifier);
Exit.addActionListener(verifier);
//Sets Labels
Amount_Label.setLabelFor(Amount_Field);
Rate_Label.setLabelFor(Rate_Box);
Term_Label.setLabelFor(Term_Box);
Payments_Label.setLabelFor(Payments_Field);
//Layout setup
JPanel labelPane = new JPanel(new GridLayout(0,1));
labelPane.add(Amount_Label);
labelPane.add(Rate_Label);
labelPane.add(Term_Label);
labelPane.add(Payments_Label);
JPanel fieldPane = new JPanel(new GridLayout(0,1));
fieldPane.add(Amount_Field);
fieldPane.add(Rate_Box);
fieldPane.add(Term_Box);
fieldPane.add(Payments_Field);
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new FlowLayout(FlowLayout.CENTER));
buttonPane.add(MortgageCalc);
buttonPane.add(Clear);
     buttonPane.add(Exit);
setBorder(BorderFactory.createEmptyBorder(25, 25, 25, 25));
add(labelPane, BorderLayout.CENTER);
add(fieldPane, BorderLayout.LINE_END);
add(buttonPane, BorderLayout.SOUTH);
class Verifier extends InputVerifier
implements ActionListener {
double MIN_AMOUNT = 100;
double MAX_AMOUNT = 9999999;
double MIN_RATE = 0.0;
int MIN_PERIOD = 1;
int MAX_PERIOD = 30;
public boolean shouldYieldFocus(JComponent input) {
boolean inputOK = verify(input);
updatePayment();
if (inputOK) {
return true;
} else {
Toolkit.getDefaultToolkit().beep();
return false;
protected void updatePayment() {
double amount = 0;
double rate = 0.0;
int termPeriods = 0;
double payment = 0.0;
//Parse numbers
try {
amount = Loan_Format.parse(Amount_Field.getText()).
doubleValue();
} catch (ParseException pe) {}
try {
rate = Rate_Format.parse(Rate_Field.getText()).
doubleValue();
} catch (ParseException pe) {}
try {
termPeriods = Term_Format.parse(Term_Field.getText()).
intValue();
} catch (ParseException pe) {}
//Calculate
payment = computePayment(amount, rate, termPeriods);
Payments_Field.setText(Payments_Format.format(payment));
public boolean verify(JComponent input) {
return checkField(input, false);
protected boolean checkField(JComponent input, boolean changeIt) {
if (input == Amount_Field) {
return checkAmount_Field(changeIt);
} else if (input == Rate_Field) {
return checkRate_Field(changeIt);
} else if (input == Term_Field) {
return checkTerm_Field(changeIt);
} else {
return true;
protected boolean checkAmount_Field(boolean change) {
boolean wasValid = true;
double amount = 0;
try {
amount = Loan_Format.parse(Amount_Field.getText()).
doubleValue();
} catch (ParseException pe) {
wasValid = false;
if ((amount < MIN_AMOUNT) || (amount > MAX_AMOUNT)) {
wasValid = false;
if (change) {
if (amount < MIN_AMOUNT) {
amount = MIN_AMOUNT;
} else {
amount = MAX_AMOUNT;
if (change) {
Amount_Field.setText(Loan_Format.format(amount));
Amount_Field.selectAll();
return wasValid;
protected boolean checkRate_Field(boolean change) {
boolean wasValid = true;
double rate = 0;
try {
rate = Rate_Format.parse(Rate_Field.getText()).
doubleValue();
} catch (ParseException pe) {
wasValid = false;
if (rate < MIN_RATE) {
wasValid = false;
if (change) {
rate = MIN_RATE;
if (change) {
Rate_Field.setText(Rate_Format.format(rate));
Rate_Field.selectAll();
return wasValid;
protected boolean checkTerm_Field(boolean change) {
boolean wasValid = true;
int termPeriods = 0;
try {
termPeriods = Term_Format.parse(Term_Field.getText()).
intValue();
} catch (ParseException pe) {
wasValid = false;
if ((termPeriods < MIN_PERIOD) || (termPeriods > MAX_PERIOD)) {
wasValid = false;
if (change) {
if (termPeriods < MIN_PERIOD) {
termPeriods = MIN_PERIOD;
} else {
termPeriods = MAX_PERIOD;
if (change) {
Term_Field.setText(Term_Format.format(termPeriods));
Term_Field.selectAll();
return wasValid;
public void actionPerformed(ActionEvent e) {
JTextField source = (JTextField)e.getSource();
shouldYieldFocus(source);
source.selectAll();
private static void createAndShowGUI() {
     JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("Week 4 Assignment - Bonnita Ludwig");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JComponent newContentPane = new week4();
newContentPane.setOpaque(true);
frame.setContentPane(newContentPane);
frame.pack();
frame.setVisible(true);
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
double computePayment(double loanAmt, double rate, int termPeriods) {
double I, partial1, denominator, answer;
termPeriods *= 12;
if (rate > 0.01) {
I = rate / 100.0 / 12.0;
partial1 = Math.pow((1 + I), (0.0 - termPeriods));
denominator = (1 - partial1) / I;
} else {
denominator = termPeriods;
answer = (-1 * loanAmt) / denominator;
return answer;
private void setUpFormats() {
Loan_Format = (NumberFormat)NumberFormat.getNumberInstance();
Rate_Format = NumberFormat.getNumberInstance();
Rate_Format.setMinimumFractionDigits(3);
Term_Format = (DecimalFormat)NumberFormat.getNumberInstance();
Term_Format.setParseIntegerOnly(true);
Payments_Format = (DecimalFormat)NumberFormat.getNumberInstance();
Payments_Format.setMaximumFractionDigits(2);
Payments_Format.setNegativePrefix("(");
Payments_Format.setNegativeSuffix(")");
/* References:
*http://java.sun.com/docs/books/tutorial/uiswing/misc/example-1dot4/index.html#InputVerificationDemo
*http://java.sun.com/docs/books/tutorial/uiswing/components/combobox.html
*/

Answer 1

Thanks for the direction, but I am still getting this error:
week4.java:377: illegal start of expression
public actionPerformed(ActionEvent e)
^
1 error
I see that I have to work on my ability to decipher code. I am very new Java and really appreciate your assistance. I have included my code after making the several changes.
Code:
import java.util.Set;
import java.util.HashSet;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;
import java.text.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.Container;
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.Graphics.*;
import java.lang.Math.*;
import java.util.*;
import java.text.NumberFormat;
import java.io.*;
import java.awt.event.*;
import javax.swing.*;
public class week4 extends JPanel
//Defines Labels
private JLabel Amount_Label;
private JLabel Rate_Label;
private JLabel Term_Label;
private JLabel Payments_Label;
//Defines Strings for Labels
private static String Amount_String = "Loan Amount: ";
private static String Rate_String = "Percentage Rate: ";
private static String Term_String = "Term (In Years): ";
private static String Payments_String = "Monthly Payment: ";
//Defines Text Fields
private JTextField Amount_Field;
private JTextField Rate_Field;
private JTextField Term_Field;
private JTextField Payments_Field;
//Defines number Formats
private NumberFormat Loan_Format;
private NumberFormat Rate_Format;
private DecimalFormat Term_Format;
private DecimalFormat Payments_Format;
private Verifier verifier = new Verifier();
//Defines Buttons
private JButton MortgageCalc = new JButton("Calculate");
     private JButton Clear = new JButton("Clear");
     private JButton Exit = new JButton("Good-bye");
     //Defines Combo Boxes
     private JComboBox Rate_Box;
     private JComboBox Term_Box;
public week4()
super(new BorderLayout());
setUpFormats();
//Creates the labels.
Amount_Label = new JLabel(Amount_String);
Rate_Label = new JLabel(Rate_String);
Term_Label = new JLabel(Term_String);
Payments_Label = new JLabel(Payments_String);
//Creates the text fields
Amount_Field = new JTextField(Loan_Format.format(0), 12);
Amount_Field.setInputVerifier(verifier);
Rate_Field = new JTextField(Rate_Format.format(0), 12);
Rate_Field.setInputVerifier(verifier);
Term_Field = new JTextField(Term_Format.format(0), 12);
Term_Field.setInputVerifier(verifier);
Payments_Field = new JTextField(Payments_Format.format(0), 12);
Payments_Field.setInputVerifier(verifier);
Payments_Field.setEditable(false);
//Creates Buttons
MortgageCalc = new JButton("Calculate");
Clear = new JButton("Clear");
Exit = new JButton("Exit");
//Creates the Combo Boxes
Rate_Box = new JComboBox ();
     Rate_Box.addItem("5.35%");
     Rate_Box.addItem("5.50%");
     Rate_Box.addItem("5.75%");
     Rate_Box.addItem("Select One");
     add(Rate_Box);
Term_Box = new JComboBox ();
     Term_box.addItem("7 years");
     Term_box.addItem("15 years");
     Term_box.addItem("30 years");
     Term_box.addItem("Select One");
     add(Term_Box);
//Defines Listner
Amount_Field.addActionListener(verifier);
Rate_Field.addActionListener(verifier);
Term_Field.addActionListener(verifier);
Rate_Box.addActionListener(verifier);
Term_box.addActionListener(verifier);
MortgageCalc.addActionListener(verifier);
Clear.addActionListner(verifier);
Exit.addActionListener(verifier);
//Sets Labels
Amount_Label.setLabelFor(Amount_Field);
Rate_Label.setLabelFor(Rate_Box);
Term_Label.setLabelFor(Term_Box);
Payments_Label.setLabelFor(Payments_Field);
//Layout setup
JPanel labelPane = new JPanel(new GridLayout(0,1));
labelPane.add(Amount_Label);
labelPane.add(Rate_Label);
labelPane.add(Term_Label);
labelPane.add(Payments_Label);
JPanel fieldPane = new JPanel(new GridLayout(0,1));
fieldPane.add(Amount_Field);
fieldPane.add(Rate_Box);
fieldPane.add(Term_Box);
fieldPane.add(Payments_Field);
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new FlowLayout(FlowLayout.CENTER));
buttonPane.add(MortgageCalc);
buttonPane.add(Clear);
     buttonPane.add(Exit);
setBorder(BorderFactory.createEmptyBorder(25, 25, 25, 25));
add(labelPane, BorderLayout.CENTER);
add(fieldPane, BorderLayout.LINE_END);
add(buttonPane, BorderLayout.SOUTH);
     class Verifier extends InputVerifier implements ActionListener
     double MIN_AMOUNT = 100;
     double MAX_AMOUNT = 9999999;
     double MIN_RATE = 0.0;
     int MIN_PERIOD = 1;
     int MAX_PERIOD = 30;
          public boolean shouldYieldFocus(JComponent input)
     boolean inputOK = verify(input);
     updatePayment();
     if (inputOK)
     return true;
     else
     Toolkit.getDefaultToolkit().beep();
     return false;
     protected void updatePayment()
     double amount = 0;
     double rate = 0.0;
     int termPeriods = 0;
     double payment = 0.0;
     //Parse numbers
     try
     amount = Loan_Format.parse(Amount_Field.getText()).
doubleValue();
     catch (ParseException pe)
     try
rate = Rate_Format.parse(Rate_Field.getText()).
doubleValue();
     catch (ParseException pe)
     try
termPeriods = Term_Format.parse(Term_Field.getText()).
intValue();
     catch (ParseException pe)
     //Calculate
     payment = computePayment(amount, rate, termPeriods);
     Payments_Field.setText(Payments_Format.format(payment));
public boolean verify(JComponent input)
return checkField(input, false);
protected boolean checkField(JComponent input, boolean changeIt)
if (input == Amount_Field)
return checkAmount_Field(changeIt);
else if (input == Rate_Field)
return checkRate_Field(changeIt);
else if (input == Term_Field)
return checkTerm_Field(changeIt);
else
return true;
protected boolean checkAmount_Field(boolean change)
boolean wasValid = true;
double amount = 0;
try
amount = Loan_Format.parse(Amount_Field.getText()).
doubleValue();
catch (ParseException pe)
wasValid = false;
if ((amount < MIN_AMOUNT) || (amount > MAX_AMOUNT))
wasValid = false;
if (change)
if (amount < MIN_AMOUNT)
amount = MIN_AMOUNT;
else
amount = MAX_AMOUNT;
if (change)
Amount_Field.setText(Loan_Format.format(amount));
Amount_Field.selectAll();
return wasValid;
protected boolean checkRate_Field(boolean change)
boolean wasValid = true;
double rate = 0;
try
rate = Rate_Format.parse(Rate_Field.getText()).
doubleValue();
catch (ParseException pe)
wasValid = false;
if (rate < MIN_RATE)
wasValid = false;
if (change)
rate = MIN_RATE;
if (change)
Rate_Field.setText(Rate_Format.format(rate));
Rate_Field.selectAll();
return wasValid;
protected boolean checkTerm_Field(boolean change)
boolean wasValid = true;
int termPeriods = 0;
try
termPeriods = Term_Format.parse(Term_Field.getText()).
intValue();
catch (ParseException pe)
wasValid = false;
if ((termPeriods < MIN_PERIOD) || (termPeriods > MAX_PERIOD))
wasValid = false;
if (change)
if (termPeriods < MIN_PERIOD)
termPeriods = MIN_PERIOD;
else
termPeriods = MAX_PERIOD;
if (change)
Term_Field.setText(Term_Format.format(termPeriods));
Term_Field.selectAll();
return wasValid;
public actionPerformed(ActionEvent e)
JTextField source = (JTextField)e.getSource();
shouldYieldFocus(source);
source.selectAll();
     public createAndShowGUI()
          JFrame.setDefaultLookAndFeelDecorated(true);
     JFrame frame = new JFrame("Week 4 Assignment - Bonnita Ludwig");
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     JComponent newContentPane = new week4();
     newContentPane.setOpaque(true);
     frame.setContentPane(newContentPane);
     frame.pack();
     frame.setVisible(true);
     public static void main(String[] args)
     javax.swing.SwingUtilities.invokeLater(new Runnable()
     public void run()
     createAndShowGUI();
     double computePayment(double loanAmt, double rate, int termPeriods)
     double I, partial1, denominator, answer;
     termPeriods *= 12;
     if (rate > 0.01)
     I = rate / 100.0 / 12.0;
     partial1 = Math.pow((1 + I), (0.0 - termPeriods));
     denominator = (1 - partial1) / I;
     else
     denominator = termPeriods;
     answer = (-1 * loanAmt) / denominator;
          return answer;
     private void setUpFormats()
     Loan_Format = (NumberFormat)NumberFormat.getNumberInstance();
     Rate_Format = NumberFormat.getNumberInstance();
     Rate_Format.setMinimumFractionDigits(3);
     Term_Format = (DecimalFormat)NumberFormat.getNumberInstance();
     Term_Format.setParseIntegerOnly(true);
     Payments_Format = (DecimalFormat)NumberFormat.getNumberInstance();
     Payments_Format.setMaximumFractionDigits(2);
     Payments_Format.setNegativePrefix("(");
     Payments_Format.setNegativeSuffix(")");
}