Reading from file into an array

Question

Hello, new to Java and we need to modify a mortgage calculator to read interest rate from a file into an array and not have them hard coded in the program. I have read many post on how to perform this but am lost on where to put the new code and format. Here is my code and I hope I posted this right.
import javax.swing.*;                                              // Imports the Main Swing Package                                   
import javax.swing.event.*;
import javax.swing.text.*;                                          // Used for  Text Box Caret Position
import java.awt.*;                                                // Imports the main AWT Package
import java.awt.event.*;                                         // Event handling class are defined here
import java.text.NumberFormat;
import java.text.*;                                              // Imports the Main Text Package
import java.util.*;                                              // Imports the Main Utility Package
public class mortgageCalculator1 extends JFrame implements ActionListener             // Creates class mortgageCalculator
    JLabel AmountLabel = new JLabel("   Enter Mortgage Amount:$ ");                   // Declares Mortgage Amount Label
    JTextField mortgageAmount = new JTextField(10);                                     // Declares Mortgage Amount Text Field
    JButton IntandTerm1B = new JButton("7 years at 5.35%");                    // Declares 1st Mortgage Term and Interest Rate
    JButton IntandTerm2B = new JButton("15 years at 5.50%");                    // Declares 2nd Mortgage Term and Interest Rate
    JButton IntandTerm3B = new JButton("30 years at 5.75%");                    // Declares 3rd Mortgage Term and Interest Rate
    JLabel PaymentLabel = new JLabel("   Monthly Payment: ");                     // Declares Monthly Payment Label
    JTextField monthlyPayment = new JTextField(10);                          // Declares Monthly Payment Text Field
    JButton exitButton = new JButton("Exit");                              // Declares Exit Button
    JButton newcalcButton = new JButton("New Calculation");                     // Declares New Calculation Button
    JTextArea mortgageTable = new JTextArea(35,65);                         // Declares Mortgage Table Area
    JScrollPane scroll = new JScrollPane(mortgageTable);                         // Declares ScrollPane and puts the Mortgage Table inside
    public mortgageCalculator1()                                        // Creates Method
         super("MORTGAGE CALCULATOR");                              // Title of Frame
         JMenuBar mb = new JMenuBar();                                   // Cretes Menu Bar
            JMenu fileMenu = new JMenu("File");                                 // Creates File Menu
         fileMenu.setMnemonic('F');                                      // Enables alt + f to Access File Menu
         JMenuItem exitItem = new JMenuItem("Exit");                     // Creates Exit in File Menu
         fileMenu.add(exitItem);                                   // Adds Exit to File Menu
             exitItem.addActionListener(new ActionListener()                     // Adds Action Listener to the Exit Item
                 public void actionPerformed(ActionEvent e)                     // Tests to Verify if File->Exit is Pressed
                     System.exit(0);                                // Exits the Programs when File->Exit is Pressed
            mb.add(fileMenu);                                      // Adds the File Menu
            setJMenuBar(mb);                              
     setSize(600, 400);                                        // Sets Size of Frame
        setLocation(200,200);                                         // Sets the Location of the Window  
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);                                  // Command on how to close frame
     JPanel pane = new JPanel();                                   // Declares the JPanel
     pane.setLayout(new BoxLayout(pane, BoxLayout.Y_AXIS));                          // Sets Panel Layout to BoxLayout
     Container grid = getContentPane();                               // Declares a Container called grid
     grid.setLayout(new GridLayout(4,3,5,5));                          // Sets grid Layout to GridLayout
     pane.add(grid);                                             // Adds the grid to the Panel
     pane.add(scroll);                                        // Addes the scrollPane to the Panel
        grid.setBackground(Color.yellow);                              // Set grid color to Yellow
     setCursor(new Cursor(Cursor.HAND_CURSOR));                         // Makes the cursor look like a hand
     mortgageAmount.setBackground(Color.black);                         // Sets mortgageAmount JPanel JTextField Background Color
        mortgageAmount.setForeground(Color.white);                         // Sets mortgageAmount JPanel JTextField Foreground Color
     mortgageAmount.setCaretColor(Color.white);                         // Sets mortgageAmount JPanel JTextField Caret Color
     mortgageAmount.setFont(new Font("Lucida Sans Typewriter", Font.PLAIN, 18));     // Sets mortgageAmount JPanel JTextField Font
     monthlyPayment.setBackground(Color.black);                         // Sets monthlyPayment JPanel JTextField Background Color
     monthlyPayment.setForeground(Color.white);                         // Sets monthlyPayment JPanel JTextField Foreground Color
        monthlyPayment.setFont(new Font("Lucida Sans Typewriter", Font.PLAIN, 18));     // Sets monthlyPayment JPanel JTextField Font
     mortgageTable.setBackground(Color.yellow);                         // Sets mortgageTable JTextArea Background Color
     mortgageTable.setForeground(Color.black);                         // Sets mortgageTable JTextArea Foreground Color
     mortgageTable.setFont(new Font("Arial", Font.PLAIN, 18));               // Sets JTextArea Font
     grid.add(AmountLabel);                                        // Adds the Mortgage Amount Label
     grid.add(mortgageAmount);                                   // Adds the Mortgage Amount Text Field
     grid.add(IntandTerm1B);                                        // Adds 1st Loan and Rate Button
     grid.add(PaymentLabel);                                    // Adds the Payment Label
     grid.add(monthlyPayment);                                    // Adds the Monthly Payment Text Field
       monthlyPayment.setEditable(false);                              // Disables editing in this Text Field
        grid.add(IntandTerm2B);                                        // Adds 2nd Loan and Rate Button
        grid.add(exitButton);
     grid.add(newcalcButton);                                    // Adds the New Calc Button
        grid.add(IntandTerm3B);                                        // Adds the Exit Button
     setContentPane(pane);                                          // Enables the Content Pane
     setVisible(true);                                          // Sets JPanel to be Visable
     exitButton.addActionListener(this);                                // Adds Action Listener to the Exit Button
     newcalcButton.addActionListener(this);                            // Adds Action Listener to the New Calc Button
        IntandTerm1B.addActionListener(this);                              // Adds Action Listener to the 1st loan Button
     IntandTerm2B.addActionListener(this);                              // Adds Action Listener to the 2nd loan Button
     IntandTerm3B.addActionListener(this);                               // Adds Action Listener to the 3rd loan Button
     mortgageAmount.addActionListener(this);                              // Adds Action Listener to the Mortgage  Amount Text Field
     monthlyPayment.addActionListener(this);                              // Adds Action Listener to the Monthly payment Text Field
    public void actionPerformed(ActionEvent e)                               // Tests to Verify Which Button is Pressed
        Object command = e.getSource();                                                 // Enables command to get data
        if (command == exitButton) //sets exitButton                         // Activates the Exit Button
            System.exit(0);  // Exits from exit button                         // Exits from exit button
        int loanTerm = 0;                                             // Declares loanTerm
        if (command == IntandTerm1B)                                   // Activates the 1st Loan Button
            loanTerm = 0;                                        // Sets 1st value of Array
        if (command == IntandTerm2B)                                   // Activates the 2nd Loan Button
            loanTerm = 1;                                        // Sets 2nd value of Array
        if (command == IntandTerm3B)                                   // Activates the 3rd Loan Button
         loanTerm = 2;                                        // Sets 3rd value of Array
            double mortgage = 0;                                   // Declares and Initializes mortgage
         double rate = 0;                                        // Declares and Initializes rate                                        
         double [][] loans = {{7, 5.35}, {15, 5.50}, {30, 5.75},};                 // Array Data for Calculation
                try
                    mortgage = Double.parseDouble(mortgageAmount.getText());            // Gets user input from mortgageAmount Text Field
                  catch (NumberFormatException nfe)                          // Checks for correct number fformatting of user input
                   JOptionPane.showMessageDialog (this, "Error! Invalid input!");      // Outputs error if number is wrong format or nothing is entered
                   return;
         double interestRate = loans [loanTerm][1];                         // Sets interestRate amount
         double intRate = (interestRate / 100) / 12;                         // Calculates Interst Rate     
            double loanTermMonths = loans [loanTerm] [0];                    // Calculates Loan Term in Months
            int months = (int)loanTermMonths * 12;                          // Converts Loan Term to Months
            double interestRateMonthly = (intRate / 12);                                // monthly interst rate
         double payment = mortgage * intRate / (1 - (Math.pow(1/(1 + intRate), months)));    // Calculation for Monthly payment
            double remainingLoanBalance = mortgage;                              // Sets Reamaining Balance
            double monthlyPaymentInterest = 0;                                       // holds current interest payment
            double monthlyPaymentPrincipal = 0;                                    // holds current principal payment
            NumberFormat myCurrencyFormatter = NumberFormat.getCurrencyInstance(Locale.US);     // Number formatter to format output in table
            monthlyPayment.setText(myCurrencyFormatter.format(payment));
            mortgageTable.setText("Month\tPrincipal\tInterest\tEnding Balance\n" +                // Formats morgageTable Header
                                  "---------\t----------\t------------\t---------------------\n");
                for (;months > 0 ; months -- )
                 monthlyPaymentInterest = (remainingLoanBalance * intRate);               // Calculation for Monthly Payment Toward Interest
                 //Calculate H = R x I
                 monthlyPaymentPrincipal = (payment - monthlyPaymentInterest);          // Calculation for Monthly Payment Toward Principal
                 //Calculate C = P - H
              remainingLoanBalance = (remainingLoanBalance - monthlyPaymentPrincipal);     // Calculation for Reamining loan Balance
              // Calculate R = R - C
              // H = monthlyPaymentInterest
              // R = remainingLoanBalance
              // P = payment
              // C = monthlyPaymentPrincipal
              // I = interestRateMonthly
              mortgageTable.setCaret (new DefaultCaret());                    // Sets Scroll position to the top left corner
              mortgageTable.append(String.valueOf(months) + "\t" +               // Pulls in data and formats MortgageTable
              myCurrencyFormatter.format(monthlyPaymentPrincipal) + "\t" +
                 myCurrencyFormatter.format(monthlyPaymentInterest) + "\t" +
                 myCurrencyFormatter.format(remainingLoanBalance) + "\n");
                       if(command == newcalcButton)                               // Activates the new calculation Button
                     mortgageAmount.setText(null);                         //clears mortgage amount fields
                  monthlyPayment.setText(null);                         //clears monthly payment fields
                        mortgageTable.setText(null);                              //clears mortgage table
public static void main(String[] args)                               //This is the signature of the entry point of all the desktop apps
     new mortgageCalculator1();
}

Answer 1

OK, making a little progress but am still very confused.
What I have is a file (int&term.dat) with three lines;
5.75, 30
5.5, 15
5.35 ,7
I have three JButtom that I what to read a seperate line and place the term in a term TextField and a rate in a Rate TextField
I have added the following code and all it does now is output a black space to the screen; I am working with one Button and Just the rate for now to try and get it to work. I have been looking at the forums, reading the internet and several books to try and figure this out. I think I may be getting closer.
public static void read()
    String line;
    StringTokenizer tokenizer;
    String rate;
    String term;
    try
        FileReader fr = new FileReader ("int&term.dat");
        BufferedReader inFile = new BufferedReader (fr);
        line = inFile.readLine();
        while (line != null)
        tokenizer = new StringTokenizer(line);
        rate = tokenizer.nextToken();
        line = inFile.readLine();
         inFile.close();
         System.out.println(new String());
         catch (FileNotFoundException exception)
               System.out.println ("The file was not found.");
          catch (IOException exception)
                System.out.println (exception);
}