Help with JTable (Swing)

I am trying to put together a mortgage calculator app that will calculate/show a monthly payment based on the entered loan amount with interest and loan term based on combo box. I am also trying to build a table based on a calculated amortization schedule. This is currently where the problem lies. I am able to build the initial table with 0 values, but am not able to populate the table with the actual amortization calculations. Hopefully there is someone out there who can help me with this as I am no longer able to come up with a logical explaination of my own.....code below:


import javax.swing.*;

import javax.swing.table.*;

import java.awt.*;

import java.awt.event.*;

import java.text.*;

import java.util.*;


public class MikeSummonsMortgageCalculatorAppWK3 extends JFrame

{

	public static void main(String [] args)

	{

		new MikeSummonsMortgageCalculatorAppWK3();

	}

	private JButton button1, button2;

	private JTextField textName1, textName2;

	private JLabel label1, label2;

	private JComboBox combo1; 

	private JTable table;

	private JScrollPane scrollPane;

	private String columnNames[];

	private String dataValues[][];

	

	public MikeSummonsMortgageCalculatorAppWK3()

	{

		//construct Frame

		this.setSize(480,530);

		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		this.setTitle("Mike Summons Mortgage Calculator - Week3");

		

		ButtonListener bl = new ButtonListener();

		

		JPanel panel1 = new JPanel();

		//panel1.setLayout(new FlowLayout(FlowLayout.LEFT));

		

		//add Loan Amount

		label1 = new JLabel("Loan Amount");

		//label1.setLayout(new BorderLayout(BorderLayout.NORTH));

		panel1.add(label1);

		textName1 = new JTextField(15);

		//textName1.setLayout(new BorderLayout(BorderLayout.NORTH));

		panel1.add(textName1);

		

		//add Loan Interest

		combo1 = new JComboBox();

		combo1.addItem("7 year at 5.35%");

		combo1.addItem("15 year at 5.50%");

		combo1.addItem("30 year at 5.75%");

		//combo1.setLayout(new BorderLayout(BorderLayout.CENTER));

		panel1.add(combo1);

		

		//add Monthly Payment

		label2 = new JLabel("Monthly Payment");

		//label2.setLayout(new BorderLayout(BorderLayout.SOUTH));

		panel1.add(label2);

		textName2 = new JTextField(15);

		//textName2.setLayout(new BorderLayout(BorderLayout.SOUTH));

		panel1.add(textName2);

		

		//add Calc button

		button1 = new JButton("Calculate");

		button1.addActionListener(bl);

		panel1.add(button1);

		

		//add Reset button

		button2 = new JButton("Reset");

		button2.addActionListener(bl);

		panel1.add(button2);

		

		String columnNames[] = {"Loan Payment", "Loan Balance", "Interest Paid"};

		

		double a = 0;

		double b = 0;

		double c = 0;

		

		String dataValues[][] =

		{

			{(String.valueOf(a)), (String.valueOf(b)), (String.valueOf(c))}

		};

		table = new JTable (dataValues, columnNames);

		table.setShowHorizontalLines(false);

		table.setRowSelectionAllowed(true);

		table.setColumnSelectionAllowed(true);

		table.setSelectionForeground(Color.white);

		table.setSelectionBackground(Color.red);

		scrollPane = new JScrollPane(table);

		panel1.add(scrollPane, BorderLayout.CENTER);

		

		this.add(panel1);

		

		this.setVisible(true);

	}

	//add button actions

	private class ButtonListener implements ActionListener

	{

		public void actionPerformed(ActionEvent e)

		{

			if (e.getSource() == button1)

			{

				int loanamount = 0;

				

				int[] loanyears;

				loanyears = new int[3];

				loanyears[0] = 7;

				loanyears[1] = 15;

				loanyears[2] = 30;

				

				double[] loaninterest;

				loaninterest = new double[3];

				loaninterest[0] = 5.35;

				loaninterest[1] = 5.50;

				loaninterest[2] = 5.75;

				

				int i = 0;

				

				NumberFormat cf = NumberFormat.getCurrencyInstance();

				

				String testAmt = textName1.getText();

				if (testAmt.length() != 0)

				{

					loanamount = Integer.parseInt(textName1.getText());

				}

				else

				{

					textName1.setText(String.valueOf("Error: No Loan Amount"));

					textName1.requestFocus();

				}

				

				String testRate = (String)combo1.getSelectedItem();

				if (testRate.equals("7 year at 5.35%"))

				{

					i = 0;

				}

				else if (testRate.equals("15 year at 5.50%"))

				{

					i = 1;

				}

				else if (testRate.equals("30 year at 5.75%"))

				{

					i = 2;

				}				

		

				//Declare/Create calculated variables

				double monthlyinterest = loaninterest[i] / 100 / 12;

				int totalpayments = loanyears[i] * 12;

				double monthlypayment = (loanamount * monthlyinterest) / (1 - Math.pow(1 / (1 + monthlyinterest), totalpayments));

		

				//Output calculated monthly payment

				textName2.setText(String.valueOf(cf.format(monthlypayment)));

				

				//Create column values

				//Table code

				for (int n = 0; n < loaninterest.length; n++)

				{

					double loanbalance;

					double loanbalance2;

					double interestpaid = loanamount * monthlyinterest;

				

					//* Output loan balance/interest paid

					loanbalance = loanamount + (loanamount * monthlyinterest);

				

					while (loanbalance > 0.00)

					{

						loanbalance2 = loanbalance - monthlypayment;

						

							String dataValues[][] =

							{

								{(String.valueOf(monthlypayment)), (String.valueOf(loanbalance2)), (String.valueOf(interestpaid))}

							};



							interestpaid = loanbalance2 * monthlyinterest;

							loanbalance = loanbalance2;

							loanbalance = loanbalance + (loanbalance * monthlyinterest);	

					}	

					//end table code

						

				}

			}	

			else if (e.getSource() == button2)

			{

				textName1.setText(String.valueOf(""));

				textName2.setText(String.valueOf(""));

			}			

		}

	}

}

---------- Post added at 03:17 PM ---------- Previous post was at 02:47 PM ----------

To narrow it down, I believe the problem lies with the dataValues variable. I declare its value as 0 to get the table itself up but can not figure out how to change the value of dataValues once the ButtonListener code goes to work.