Unable to getText the value of string - java

I'm preparing a simple system as my assignment, And I'm facing a problem where I dont know how to getText the value of String. I know how to do it with integer, but not with string.
I use Integer.parseInt(t2.getText()); in my code if i want to get an integer value
I have added my code into this.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class tollRate extends JFrame implements ActionListener {
JLabel L1 = new JLabel("Please insert your origin (in capital letter)");
JTextField t1 = new JTextField(20);
JLabel L2 = new JLabel("Please insert your destination (in capital letter)");
JTextField t2 = new JTextField(20);
JLabel L3 = new JLabel("Your vehicle class");
JTextField t3 = new JTextField(1);
JButton b1 = new JButton("Calculate");
JButton b2 = new JButton("Exit");
JLabel L4 = new JLabel("Class 0 : Motorcycles, bicycles, or vehicles with "
+ "2 or less wheels" + "\nClass 1 : Vehicles wit 2 axles and 3 "
+ "or 4 wheels excluding taxis" + "\nClass 2 : Vehicles with 2 "
+ "axles and 5 or 6 wheels excluding busses" + "\n Class 3 : "
+ "Vehicles with 3 or more axles" + "\nClass 4 : Taxis"
+ "\nClass 5 : Buses");
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
JPanel p3 = new JPanel();
JPanel p4 = new JPanel();
JPanel p5 = new JPanel();
String i, j, k;
tollRate() {
JFrame a = new JFrame();
setTitle("Highway Toll Rates System");
setSize(600, 400);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new GridLayout(5, 2));
p1.setLayout(new GridLayout(1, 2));
p1.add(L1);
p1.add(t1);
p2.setLayout(new GridLayout(1, 2));
p2.add(L2);
p2.add(t2);
p3.setLayout(new GridLayout(1, 2));
p3.add(L3);
p3.add(t3);
p4.setLayout(new FlowLayout());
p4.add(b1);
p4.add(b2);
p5.setLayout(new FlowLayout());
p5.add(L4);
add(p1);
add(p2);
add(p3);
add(p4);
add(p5);
b1.addActionListener(this);
b2.addActionListener(this);
}
public void actionPerformed(ActionEvent a) {
Object source = a.getSource();
if (source == b2) {
this.dispose();
} else if (source == b1) {
i = Integer.parseInt(t1.getText());
j = Integer.parseInt(t2.getText());
k = Integer.parseInt(t3.getText());
}
}
public static void main(String[] args) {
tollRate a = new tollRate();
}
}

First of all String i, j, k;
i = Integer.parseInt(t1.getText());
j = Integer.parseInt(t2.getText());
k = Integer.parseInt(t3.getText());
This is wrong. You are assigning String for int. Correct them first. and if you want int values it is better to use
int i, j, k; and use trim() to avoid additional spaces.
i = Integer.parseInt(t1.getText().trim());
j = Integer.parseInt(t2.getText().trim());
k = Integer.parseInt(t3.getText().trim());
In your case use as follows
i = t1.getText();
j = t2.getText();
k = t3.getText();

to assign a string to a string all you need to do is
i = t1.getText();
j = t2.getText();
k = t3.getText();
as you have created them as strings already

Related

can JTextField resizable in a gridlayout?

Below is my code for testing BorderLayout and GridLayout, but I found that the JTextField in the JPanel using GridLayout is not resizable, no matter how many times I change the JTextField.setPreferredSize, it still remains the same.
public class Boderlayout implements ActionListener {
JButton bCalculate;
JLabel lPrinAmount,lInterestRate,lPayPerYear,lResult;
JTextField tPrinAmount,tInterestRate,tPayPerYear,tResult;
public static void main (String[] args) {
new Boderlayout();
}
public Boderlayout() {
JFrame frame = new JFrame();
frame.setLayout(new BorderLayout());
JPanel p2 = new JPanel();
p2.setBackground(Color.BLUE);
p2.setPreferredSize(new Dimension(600,100));
frame.add(p2,BorderLayout.SOUTH);
bCalculate = new JButton("Calculate");
bCalculate.setPreferredSize(new Dimension(550,85));
p2.add(bCalculate);
bCalculate.addActionListener(this);
JPanel p3 = new JPanel();
p3.setBackground(Color.GREEN);
p3.setLayout(new GridLayout(6,1));
p3.setPreferredSize(new Dimension(300,300));
frame.add(p3,BorderLayout.CENTER);
lPrinAmount = new JLabel("Principle Amount: ");
lPrinAmount.setPreferredSize(new Dimension(200,40));
p3.add(lPrinAmount);
tPrinAmount = new JTextField(20);
tPrinAmount.setPreferredSize(new Dimension(170,40));
p3.add(tPrinAmount);
tPrinAmount.addActionListener(this);
lInterestRate = new JLabel("Interest Rate: ");
lInterestRate.setPreferredSize(new Dimension(200,40));
p3.add(lInterestRate);
tInterestRate = new JTextField(20);
tInterestRate.setPreferredSize(new Dimension(100,40));
p3.add(tInterestRate);
tInterestRate.addActionListener(this);
lPayPerYear = new JLabel("Payment Period (Year): ");
lPayPerYear.setPreferredSize(new Dimension(200,40));
p3.add(lPayPerYear);
tPayPerYear = new JTextField(20);
tPayPerYear.setPreferredSize(new Dimension(170,40));
p3.add(tPayPerYear);
tPayPerYear.addActionListener(this);
JPanel p5 = new JPanel();
p5.setLayout(new GridLayout(2,1));
p5.setBackground(Color.WHITE);
p5.setPreferredSize(new Dimension(300,300));
frame.add(p5,BorderLayout.EAST);
lResult = new JLabel("Result");
lResult.setPreferredSize(new Dimension(170,40));
p5.add(lResult);
tResult = new JTextField(50);
tResult.setPreferredSize(new Dimension(170,200));
tResult.setEditable(false);
p5.add(tResult);
frame.pack();
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
if (e.getSource() == bCalculate) {
double prinAmount = Double.parseDouble(tPrinAmount.getText());
double interestRate = Integer.parseInt(tInterestRate.getText());
double paymentYear = Integer.parseInt(tPayPerYear.getText());
double interestRatePercentage = interestRate / 100;
double loanInterest = prinAmount * interestRatePercentage;
double year = 12 * paymentYear;
double mortgageResult = (loanInterest * (Math.pow((1 + (interestRatePercentage / 12)), year)) / (Math.pow((1 + (interestRatePercentage) / 12), year) - 1)) / 12;
String stringmortgageResult = Double.toString(mortgageResult);
String newline = System.getProperty("line.separator");
String finalResult = "Principle Amount: " + tPrinAmount.getText() + newline + "Interest Rate: " + tInterestRate.getText() + "%" + newline + "Payment Period: " + tPayPerYear.getText()
+ newline + "Mortgage: " + stringmortgageResult;
tResult.setText(finalResult);
}
}
}
Refer to How to Use GridLayout.
Here is a quote from that Web page:
A GridLayout object places components in a grid of cells. Each component takes all the available space within its cell, and each cell is exactly the same size.
In other words, GridLayout does not consider the preferred size of the components it contains.
A layout manager that does consider its contained components' preferred size is GridBagLayout.
BorderLayout only respects part of its contained components' preferred size. For the EAST component, BorderLayout uses its preferred width but not its preferred height. BorderLayout will initially use its CENTER component's preferred width and height.
This is the window I get when I run your code.
Here is your modified code using GridBagLayout instead of GridLayout.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class Boderlayout implements ActionListener {
JButton bCalculate;
JLabel lPrinAmount, lInterestRate, lPayPerYear, lResult;
JTextArea tResult;
JTextField tPrinAmount, tInterestRate, tPayPerYear;
public static void main(String[] args) {
new Boderlayout();
}
public Boderlayout() {
JFrame frame = new JFrame();
JPanel p2 = new JPanel();
p2.setBackground(Color.BLUE);
p2.setPreferredSize(new Dimension(600, 100));
frame.add(p2, BorderLayout.SOUTH);
bCalculate = new JButton("Calculate");
bCalculate.setPreferredSize(new Dimension(550, 85));
p2.add(bCalculate);
bCalculate.addActionListener(this);
JPanel p3 = new JPanel();
p3.setBackground(Color.GREEN);
p3.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
p3.setPreferredSize(new Dimension(300, 300));
frame.add(p3, BorderLayout.CENTER);
lPrinAmount = new JLabel("Principle Amount: ");
lPrinAmount.setPreferredSize(new Dimension(200, 40));
gbc.gridx = 0;
gbc.gridy = 0;
p3.add(lPrinAmount, gbc);
tPrinAmount = new JTextField(20);
tPrinAmount.setPreferredSize(new Dimension(170, 40));
gbc.gridy = 1;
p3.add(tPrinAmount, gbc);
tPrinAmount.addActionListener(this);
lInterestRate = new JLabel("Interest Rate: ");
lInterestRate.setPreferredSize(new Dimension(200, 40));
gbc.gridy = 2;
p3.add(lInterestRate, gbc);
tInterestRate = new JTextField(20);
tInterestRate.setPreferredSize(new Dimension(100, 40));
gbc.gridy = 3;
p3.add(tInterestRate, gbc);
tInterestRate.addActionListener(this);
lPayPerYear = new JLabel("Payment Period (Year): ");
lPayPerYear.setPreferredSize(new Dimension(200, 40));
gbc.gridy = 4;
p3.add(lPayPerYear, gbc);
tPayPerYear = new JTextField(20);
tPayPerYear.setPreferredSize(new Dimension(170, 40));
gbc.gridy = 5;
p3.add(tPayPerYear, gbc);
tPayPerYear.addActionListener(this);
JPanel p5 = new JPanel();
p5.setLayout(new BoxLayout(p5, BoxLayout.PAGE_AXIS));
p5.setBackground(Color.WHITE);
p5.setPreferredSize(new Dimension(300, 300));
frame.add(p5, BorderLayout.EAST);
lResult = new JLabel("Result");
lResult.setPreferredSize(new Dimension(170, 40));
p5.add(lResult);
tResult = new JTextArea();
tResult.setPreferredSize(new Dimension(170, 200));
tResult.setEditable(false);
tResult.setBorder(BorderFactory.createLineBorder(Color.darkGray));
p5.add(tResult);
frame.pack();
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == bCalculate) {
double prinAmount = Double.parseDouble(tPrinAmount.getText());
double interestRate = Integer.parseInt(tInterestRate.getText());
double paymentYear = Integer.parseInt(tPayPerYear.getText());
double interestRatePercentage = interestRate / 100;
double loanInterest = prinAmount * interestRatePercentage;
double year = 12 * paymentYear;
double mortgageResult = (loanInterest
* (Math.pow((1 + (interestRatePercentage / 12)), year))
/ (Math.pow((1 + (interestRatePercentage) / 12), year) - 1)) / 12;
String stringmortgageResult = Double.toString(mortgageResult);
String newline = System.getProperty("line.separator");
String finalResult = "Principle Amount: " + tPrinAmount.getText() + newline
+ "Interest Rate: " + tInterestRate.getText() + "%" + newline
+ "Payment Period: " + tPayPerYear.getText() + newline + "Mortgage: "
+ stringmortgageResult;
tResult.setText(finalResult);
}
}
}
This is the window I get when I run the above code.
Note that I changed tResult to JTextArea rather than JTextField.

Random Number won't appear in a JTextField

I have a problem.I created a program that will add two random numbers. I'm trying to put a Math.random() in a JTextField but it won't appear. Here's my code by the way:
public class RandomMathGame extends JFrame {
public RandomMathGame(){
super("Random Math Game");
int random2;
JButton lvl1 = new JButton("LEVEL 1");
JButton lvl2 = new JButton("LEVEL 2");
JButton lvl3 = new JButton("LEVEL 3");
JLabel line1 = new JLabel("Line 1: ");
final JTextField jtf1 = new JTextField(10);
JLabel line2 = new JLabel("Line 2: ");
final JTextField jtf2 = new JTextField(10);
JLabel result = new JLabel("Result: ");
final JTextField jtf3 = new JTextField(10);
JButton ans = new JButton("Answer");
JLabel score = new JLabel("Score: ");
JTextField jtf4 = new JTextField(3);
JLabel itm = new JLabel("Number of Items: ");
JTextField items = new JTextField(3);
FlowLayout flo = new FlowLayout();
setLayout(flo);
add(lvl1);
add(lvl2);
add(lvl3);
add(line1);
add(jtf1);
add(line2);
add(jtf2);
add(result);
add(jtf3);
add(ans);
add(score);
add(jtf4);
add(itm);
add(items);
setSize(140,400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
lvl1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
int i, j = 10;
int i1 = Integer.valueOf(jtf1.getText());
int i2 = Integer.valueOf(jtf2.getText());
int i3 = i1 + i2;
final int random1 = (int)(Math.random() * 10 + 1);
for (i = 0; i <= j + 1; i++){
try{
jtf1.setText(String.valueOf(random1));
jtf2.setText(String.valueOf(random1));
jtf3.setText(String.valueOf(i3));
}catch(Exception ex){
ex.printStackTrace();
}
}
}
});
}
Never mind the lvl2 and lvl3 because it's the same in lvl1. And also, I want to loop them 10 times. I'm having difficulties on putting up those codes. Can someone help me? Thanks for your help. :)
Updating text fields in a loop won't produce the animated display that you likely want; only the last update will be seen. Instead, use a javax.swing.Timer to periodically update the fields. Related examples may be found here, here and here.

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: empty String

I've been having problems running this program it compiles but doesn't run properly. When I run it and attempt to perform the calculations it spits out a bunch errors. I think it has to with variable types. Here is the program:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class area extends JFrame implements ActionListener, ItemListener{
//row 1
JPanel row1 = new JPanel();
JLabel select = new JLabel("Please select what you would like to caculate the area and volume of.");
//row 2
JPanel row2 = new JPanel();
JCheckBox circle = new JCheckBox("Circle", false);
JCheckBox cube = new JCheckBox("Cube", false);
//row 3
JPanel row3 = new JPanel();
JLabel radlab = new JLabel("Radius of the circle (in cm)");
JTextField rad = new JTextField(3);
JLabel sidelab = new JLabel("A side of the cube (in cm)");
JTextField side = new JTextField(3);
//row4
JPanel row4 = new JPanel();
JButton solve = new JButton("Solve!");
//row 5
JPanel row5 = new JPanel();
JLabel areacallab = new JLabel("Area");
JTextField areacal = new JTextField(10);
JLabel volumelab = new JLabel("Volume");
JTextField volume = new JTextField(10);
public area(){
setTitle("Area Caculator");
setSize(500,400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
//disables all text areas
rad.setEnabled(false);
side.setEnabled(false);
areacal.setEnabled(false);
volume.setEnabled(false);
//add listeners
circle.addItemListener(this);
cube.addItemListener(this);
solve.addActionListener(this);
FlowLayout one = new FlowLayout(FlowLayout.CENTER);
setLayout(one);
row1.add(select);
add(row1);
row2.add(circle);
row2.add(cube);
add(row2);
row3.add(radlab);
row3.add(rad);
row3.add(sidelab);
row3.add(side);
add(row3);
row4.add(solve);
add(row4);
row5.add(areacallab);
row5.add(areacal);
row5.add(volumelab);
row5.add(volume);
add(row5);
}
public void circlepick(){
//cube.setCurrent(false);
cube.setEnabled(false);
rad.setEnabled(true);
}
public void cubepick(){
circle.setEnabled(false);
side.setEnabled(true);
}
#Override
public void itemStateChanged(ItemEvent event) {
Object item = event.getItem();
if (item == circle){
circlepick();
}
else if (item == cube){
cubepick();
}
}
#Override
public void actionPerformed(ActionEvent evt){
//String radi = rad.getText();
//String sid = side.getText();
//circlesolve();
//cubesolve();
String radi = rad.getText();
String sid = side.getText();
double radius = Double.parseDouble(radi);
double length = Double.parseDouble(sid);
double cirarea = Math.PI * Math.pow(radius, 2);
double cirvolume = (4.0 / 3) * Math.PI * Math.pow(radius, 3);
double cubearea = Math.pow(length, 2);
double cubevolume = Math.pow(length, 3);
areacal.setText("" + cirarea + cubearea + "");
volume.setText("" + cirvolume + cubevolume + "");
}
public static void main(String[] args) {
area are = new area();
}
}
Here are the errors is printing out when attempting to perform the math (sorry it really long).
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: empty String
at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1038)
at java.lang.Double.parseDouble(Double.java:548)
at area.actionPerformed(area.java:112)
...
Thanks so much in advance for an help!
When calling the functions:
double radius = Double.parseDouble(radi);
double length = Double.parseDouble(sid);
either radi or sid is am Empty String, thats what
java.lang.NumberFormatException: empty String
tells you.
You might consider adding a System.out.println(raid + ", " + sid) before parsing to check what values are empty Strings and make sure, that the Strings are not empty.
Double.parseDouble(String s) throws a NumberFormatException when the given String s can not be parsed into a double value.

Java Program error (TextField)

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class NICCode extends JFrame {
NICCode() {
setSize(600, 250);
setResizable(false);
setDefaultCloseOperation(3);
setLocationRelativeTo(null);
// JPanel
JPanel labelPanel = new JPanel(new FlowLayout(1));
JPanel leftBodyPanel = new JPanel(new GridLayout(3, 1));
JPanel bodyPanel = new JPanel(new GridLayout(3, 1));
JPanel buttonPanel = new JPanel(new FlowLayout(2));
JPanel textFieldPanel = new JPanel(new FlowLayout(0));
// JLabel
JLabel titleLabel = new JLabel("Find Your Birthday By NIC");
titleLabel.setFont(new Font("", 1, 25));
JLabel myLabel = new JLabel("CSG");
myLabel.setFont(new Font("", 1, 10));
JLabel enterNicLabel = new JLabel("Enter Your NIC :");
JLabel yourBirthDayLabel = new JLabel("Your Birth Day :");
JLabel yourGenderLabel = new JLabel("Gender :");
JLabel printBirthDayLabel = new JLabel("Your Birth Day");
JLabel printGenderLabel = new JLabel("Your Gender");
// JTextField
JTextField nicText = new JTextField(25);
nicText.setText("920000000V");
// JButton
JButton searchAgainButton = new JButton("Search Again");
JButton exitButton = new JButton("Exit");
// adds
add("North", labelPanel);
add("West", leftBodyPanel);
add("South", buttonPanel);
add(bodyPanel);
labelPanel.add(titleLabel);
leftBodyPanel.add(enterNicLabel);
leftBodyPanel.add(yourBirthDayLabel);
leftBodyPanel.add(yourGenderLabel);
textFieldPanel.add(nicText);
bodyPanel.add(textFieldPanel);
bodyPanel.add(printBirthDayLabel);
bodyPanel.add(printGenderLabel);
buttonPanel.add(myLabel);
buttonPanel.add(searchAgainButton);
buttonPanel.add(exitButton);
setVisible(true);
// pack();
String yearText = nicText.substring(0, 2);
String dateText = nicText.substring(2, 5);
String sex = "";
int year = Integer.parseInt(yearText);
int date = Integer.parseInt(dateText);
int month = 0;
if (date > 500) {
sex = "Feamale";
date -= 500;
} else {
sex = "Male";
}
int datesOfMonths[] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
for (int i = 0; i < 12; i++) {
date = date - datesOfMonths[i];
month = i;
if (date < datesOfMonths[i + 1]) {
break;
}
}
if (month > 0) {
month += 1;
}
}
}
I just created a program for find birthday from nic. I couldn't fix this compile error.
I created a JTextField to get Nic, then I added substring methods to get the needed numbers to find nic. Unfortunately the substring methods can't find textField. It shows error as 'cannot find symbol'. It's a TextField. Why can't the method find that TextField.?
The message:
cannot find symbol
Is not referring to the text field, but the method substring(..) which does not exist for JTextField. But something like..
textField.getText().substring(...);
..probably will work, since getText() returns a String and String has that method.
Change
String yearText = nicText.substring(0, 2);
String dateText = nicText.substring(2, 5);
to
String yearText = nicText.getText().substring(0, 2);
String dateText = nicText.getText().substring(2, 5);

Java radio buttons

I'm having trouble with my radio buttons. I can click on all three at the same time. It should be when you click on one the other one turns off?
I'm using a grid layout. So when I try group.add it doesn't work.
Example:
I have the buttons declared like this
JRadioButton seven = new JRadioButton("7 years at 5.35%", false);
JRadioButton fifteen = new JRadioButton("15 years at 5.5%", false);
JRadioButton thirty = new JRadioButton("30 years at 5.75%", false);
ButtonGroup group = new ButtonGroup();
grid.add(seven);
grid.add(fifteen);
grid.add(thirty);
This is my code:
/*Change Request #6
Write the program in Java (with a graphical user interface)
so that it will allow the user to select which way
they want to calculate a mortgage:
by input of the amount of the mortgage,
the term of the mortgage,
and the interest rate of the mortgage payment
or by input of the amount of a mortgage and
then select from a menu of mortgage loans:
- 7 year at 5.35%
- 15 year at 5.5 %
- 30 year at 5.75%
In either case, display the mortgage payment amount
and then, list the loan balance and interest paid
for each payment over the term of the loan.
Allow the user to loop back and enter a new amount
and make a new selection, or quit.
Insert comments in the program to document the program.
*/
import java.text.NumberFormat;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class WK4 extends JFrame implements ActionListener
{
int loanTerms[] = { 7, 15, 30 };
double annualRates[] = { 5.35, 5.5, 5.75 };
// Labels
JLabel AmountLabel = new JLabel(" Loan Amount $ ");
JLabel PaymentLabel = new JLabel(" Monthly Payment ");
JLabel InterestLabel = new JLabel(" Interest Rate % ");
JLabel TermLabel = new JLabel(" Years of Loan ");
// Text Fields
JTextField mortgageAmount = new JTextField(6);
JTextField Payment = new JTextField(6);
JTextField InterestRate = new JTextField(3);
JTextField Term = new JTextField(3);
// Radio Buttons
ButtonGroup radioGroup = new ButtonGroup();
JRadioButton seven = new JRadioButton("7 years at 5.35%");
JRadioButton fifteen = new JRadioButton("15 years at 5.5%");
JRadioButton thirty = new JRadioButton("30 years at 5.75%");
// Buttons
JButton exitButton = new JButton("Exit");
JButton resetButton = new JButton("Reset");
JButton calculateButton = new JButton("Calculate ");
// Text Area
JTextArea LoanPayments = new JTextArea(20, 50);
JTextArea GraphArea = new JTextArea(20, 50);
JScrollPane scroll = new JScrollPane(LoanPayments);
public WK4(){
super("Mortgage Calculator");
//Window
setSize(700, 400);
setLocation(200, 150);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel pane = new JPanel(new GridLayout(2, 2));
Container grid = getContentPane();
grid.setLayout(new GridLayout(4, 10, 0, 12)); //rows, cols, hgap, vgap
pane.add(grid);
pane.add(scroll);
grid.add(AmountLabel);
grid.add(mortgageAmount);
grid.add(InterestLabel);
grid.add(InterestRate);
grid.add(TermLabel);
grid.add(Term);
grid.add(PaymentLabel);
grid.add(Payment);
grid.add(Box.createHorizontalStrut(15));
ButtonGroup group = new ButtonGroup();
grid.add(seven);
grid.add(fifteen);
grid.add(thirty);
grid.add(calculateButton);
grid.add(resetButton);
grid.add(exitButton);
Payment.setEditable(false);
setContentPane(pane);
setContentPane(pane);
setVisible(true);
// Action Listeners
mortgageAmount.addActionListener(this);
InterestRate.addActionListener(this);
Term.addActionListener(this);
Payment.addActionListener(this);
seven.addActionListener(this);
fifteen.addActionListener(this);
thirty.addActionListener(this);
calculateButton.addActionListener(this);
exitButton.addActionListener(this);
resetButton.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
Object command = e.getSource();
if (command == exitButton) {
System.exit(0);
}
else if (command == seven) {
calcLoan(loanTerms[0], annualRates[0]);
}
else if (command == fifteen) {
calcLoan(loanTerms[1], annualRates[1]);
}
else if (command == thirty) {
calcLoan(loanTerms[2], annualRates[2]);
}
else if (command == calculateButton) {
double years = 0;
double rates = 0;
try {
years = Double.parseDouble(Term.getText());
rates = Double.parseDouble(InterestRate.getText());
}
catch (Exception ex) {
LoanPayments.setText("Invalid Amount");
return;
}
calcLoan(years, rates);
}
else if (command == resetButton) {
mortgageAmount.setText("");
Payment.setText("");
InterestRate.setText("");
Term.setText("");
LoanPayments.setText("");
}
}
private void calcLoan(double years, double rates) {
Term.setText(String.valueOf(years));
InterestRate.setText(String.valueOf(rates));
double amount = 0;
try {
amount = Double.parseDouble(mortgageAmount.getText());
}
catch (Exception ex) {
LoanPayments.setText("Invalid Amount");
return;
}
double interestRate = rates;
double intRate = (interestRate / 100) / 12;
int months = (int) years * 12;
double rate = (intRate / 12);
double payment = amount * intRate
/ (1 - (Math.pow(1 / (1 + intRate), months)));
double remainingPrincipal = amount;
double MonthlyInterest = 0;
double MonthlyAmt = 0;
NumberFormat CurrencyFormatter = NumberFormat.getCurrencyInstance();
Payment.setText(CurrencyFormatter.format(payment));
LoanPayments.setText(" Month\tPrincipal\tInterest\tEnding Balance\n");
int currentMonth = 0;
while (currentMonth < months) {
MonthlyInterest = (remainingPrincipal * intRate);
MonthlyAmt = (payment - MonthlyInterest);
remainingPrincipal = (remainingPrincipal - MonthlyAmt);
LoanPayments.append((++currentMonth) + "\t"
+ CurrencyFormatter.format(MonthlyAmt) + "\t"
+ CurrencyFormatter.format(MonthlyInterest) + "\t"
+ CurrencyFormatter.format(remainingPrincipal) + "\n");
GraphArea.append("" + remainingPrincipal);
}
}
public static void main(String[] args) {
new WK4();
}
}
You're adding the radio buttons to the grid but you also need to add them to the button group that you defined.
Maybe this:
ButtonGroup group = new ButtonGroup();
grid.add(seven);
grid.add(fifteen);
grid.add(thirty);
Should be this: ??? (Copy/paste bug?)
ButtonGroup group = new ButtonGroup();
group.add(seven);
group.add(fifteen);
group.add(thirty);
Or maybe you need to do both. The radio buttons have to belong to a container as well as a button group to be displayed and to behave properly.

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