Java Mortgage Calculator

Question

Im having trouble making my GUI look the way I want it. Obviously I dont know enough about Gridlayout And I think I need to use GridBagLayout instead. I need the amortization schedule to print all the way out and everything to line up. If anyone has some suggestions I would love to hear it, and yes, this is my homework. see the code below:
Main java file: implements MyFrame4 java file
import java.awt.*; //imports awt
public class MortgageCalculator4 {   // main MortgageCalculator class constuctor
public static void main(String args[]) {  //implements MyFrame4
Frame f = new MyFrame4();
} //end of MortgageCalculator4 class
Adapter java file: implements WindowAdapter
import java.awt.*; //imports awt
import java.awt.event.*;
class MyAdapter extends WindowAdapter {   //creates window adapter
Frame myFrame;
MyAdapter(Frame f) {
super();
myFrame = f;
public void windowClosing(WindowEvent e) {
myFrame.dispose();
} //end of MyAdapter class
Frame java file: main body of program implemented by MortgageCalculator file
import java.awt.*; //imports awt's
import java.awt.event.*;
import java.text.DecimalFormat;
import javax.swing.*;
class MyFrame4 extends Frame implements TextListener, ActionListener {    //class constructs the frame and layout
Button loanButton1 = new Button("Loan 1"), //creates and labels buttons
loanButton2 = new Button("Loan 2"),
loanButton3 = new Button("Loan 3"),
clearButton = new Button("clear/New");
TextField principalField = new TextField("0.00", 15), //sets TextField properties
rateField = new TextField("0.00", 3), //adds field lenghts and initial properties
yearsField = new TextField("0", 3),
paymentField = new TextField("0.00", 15),
intpaymentTextArea = new TextField("0.00", 40);
double principal, rate, ratePercent; //assigns variables
int years, n;
final int paymentsPerYear = 12;
final int timesPerYearCalculated = 12;
double effectiveAnnualRate;
double payment;      
public MyFrame4() { //beginnig of frame constructor
setTitle("Mortgage Payment Calculator");
setLayout(new GridLayout(14, 2));
Label title1Label = new Label("Enter loan amount then select a loan option");
Label title2Label = new Label("or enter an interest rate and years");
Label principalLabel = new Label("Loan Amount $"), // constructs labels
rateLabel = new Label("Rate (%)"),
yearsLabel = new Label("Years"),
loan1Label = new Label("7 years at 5.35%"), //asigns labels
loan2Label = new Label("15 years at 5.5%"),
loan3Label = new Label("30 years at 5.75%%"),
paymentLabel = new Label("Payment $"),
intpaymentLabel = new Label("Ammortization Schedule");
Panel title1LabelPanel = new Panel (new FlowLayout(FlowLayout.RIGHT));
Panel title2LabelPanel = new Panel (new FlowLayout(FlowLayout.RIGHT));
Panel principalLabelPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)), // places label positions and button panels
loan1LabelPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
loan2LabelPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
loan3LabelPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
rateLabelPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
yearsLabelPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
paymentLabelPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
intpaymentLabelPanel = new Panel(new FlowLayout(FlowLayout.CENTER));
Panel principalFieldPanel = new Panel(new FlowLayout(FlowLayout.LEFT)),
loan1ButtonPanel = new Panel(new FlowLayout(FlowLayout.LEFT)),
loan2ButtonPanel = new Panel(new FlowLayout(FlowLayout.LEFT)),
loan3ButtonPanel = new Panel(new FlowLayout(FlowLayout.LEFT)),
rateFieldPanel = new Panel(new FlowLayout(FlowLayout.LEFT)),
yearsFieldPanel = new Panel(new FlowLayout(FlowLayout.LEFT)),
paymentFieldPanel = new Panel(new FlowLayout(FlowLayout.LEFT)),
clearButtonPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
blankPanel = new Panel(new FlowLayout(FlowLayout.RIGHT)),
intpaymentTextAreaPanel = new Panel(new FlowLayout(FlowLayout.RIGHT));
title1LabelPanel.add(title1Label);
title1LabelPanel.add(title2Label);
principalLabelPanel.add(principalLabel); //adds labels buttons and fields
principalFieldPanel.add(principalField);
loan1LabelPanel.add(loan1Label);
loan1ButtonPanel.add(loanButton1);
loan2LabelPanel.add(loan2Label);
loan2ButtonPanel.add(loanButton2);
loan3LabelPanel.add(loan3Label);
loan3ButtonPanel.add(loanButton3);
clearButtonPanel.add(clearButton);
rateLabelPanel.add(rateLabel);
rateFieldPanel.add(rateField);
rateField.setEditable(true);
yearsLabelPanel.add(yearsLabel);
yearsFieldPanel.add(yearsField);
yearsField.setEditable(true);
paymentLabelPanel.add(paymentLabel);
paymentFieldPanel.add(paymentField);
paymentField.setEditable(false);
intpaymentLabelPanel.add(intpaymentLabel);
intpaymentTextAreaPanel.add(intpaymentTextArea);
intpaymentTextArea.setEditable(false);
add(title1LabelPanel);
add(title2LabelPanel);
add(principalLabelPanel);
add(principalFieldPanel);
add(loan1LabelPanel);
add(loan1ButtonPanel);
add(loan2LabelPanel);
add(loan2ButtonPanel);
add(loan3LabelPanel);
add(loan3ButtonPanel);
add(rateLabelPanel);
add(rateFieldPanel);
add(yearsLabelPanel);
add(yearsFieldPanel);
add(paymentLabelPanel);
add(paymentFieldPanel);
add(clearButtonPanel);
add(intpaymentLabelPanel);
add(blankPanel);
add(intpaymentTextAreaPanel);
loanButton1.addActionListener(this); //assigns ActionListener to buttons
loanButton2.addActionListener(this);
loanButton3.addActionListener(this);
clearButton.addActionListener(this);
principalField.addTextListener(this); //adds TextListener to fields
rateField.addTextListener(this);
yearsField.addTextListener(this);
addWindowListener(new MyAdapter(this));
pack(); //resizes window to fit components
setVisible(true);
DecimalFormat currency = new DecimalFormat("####0.00"); //sets currency format
public void actionPerformed(ActionEvent e){ //checks for buttons clicked and sets variables to fields
     //wanted to get data from array but couldnt make it work
          if(e.getSource() == loanButton1){
               rateField.setText("5.85");
               yearsField.setText("7");
     if(e.getSource() == loanButton2){
               rateField.setText("5.5");
          yearsField.setText("20");           
          if(e.getSource() == loanButton3){
               rateField.setText("5.75");
          yearsField.setText("30");     
          if(e.getSource() == clearButton){
               rateField.setText("0.00");
          yearsField.setText("0");
          principalField.setText("0.00");           
public void textValueChanged(TextEvent e) {  //checks field variables and sends to calculations
Object source = e.getSource();
if (source == principalField
|| source == rateField
|| source == yearsField) {
try {
principal = Double.parseDouble(principalField.getText()); //perform calculations for payment
ratePercent = Double.parseDouble(rateField.getText());
rate = ratePercent / 100.0;
years = Integer.parseInt(yearsField.getText());
n = paymentsPerYear * years;
effectiveAnnualRate = rate / paymentsPerYear;
payment =
principal
* (effectiveAnnualRate
/ (1 - Math.pow(1 + effectiveAnnualRate, -n)));
DecimalFormat payForm = new DecimalFormat("####.##"); //performs calculations for Ammortization text area
int num_Months = years*12;     
double i = ratePercent/1200;
payment = principal*((i*(Math.pow((1+i),num_Months)))/((Math.pow((1+i),num_Months))-1));               
int num_Payments = num_Months-1;
int month_counter = 0;
double intPaid = 0;
double balance = principal;
intpaymentTextArea.setText("");
while (month_counter <= num_Months){
intPaid = balance * i;
balance = balance - (payment - intPaid);
intpaymentTextArea.setText(("Month ")+month_counter+( " - Payment: $")
payForm.format(payment)" Balance: "
payForm.format(balance)(" Interest Paid: $")
payForm.format(intPaid)"\n");
month_counter++;
paymentField.setText(currency.format(payment)); //display payment
} catch (NumberFormatException ex) {  //catch exceptions
} //end of MyFrame4 Class

Answer 1

Another suggestion is post only the necessary code that exemplifies the unexpected behavior, and don't forget to use code tags when you're posting code. Look for CODE button when writing the post! This way your code will be well formatted and more readable. It also increases the chance of someone reading it and help you.