Application To Applet, Java Example Java Applet Applet Versus Application

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sonya

application to applet,
February 28, 2009 at 8:53 PM

Hi!
I am trying to convert an application program to an applet and it keeps giving me errors. Can someone look at it and let me know what the problem is?
thanks.
heres' my source code:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class LoanPay2 extends JApplet implements ItemListener
{
private JLabel amount, interest, months, payment, total;
private JTextField amountTF, interestTF, monthsTF, paymentTF,

totalTF;
private JButton calculate, reset;

public void init()
{
// Create the Title for the Window
//setTitle("Loan Payment");

// Set the Size of the Window
//setSize(300,300);

//Get the container
Container c = getContentPane();

// Set the Layout
c.setLayout(null);

// Create, Size, and Locate Labels and Text Fields
amount = new JLabel("Loan Amount");
amount.setSize(140,30);
amount.setLocation(10, 10);
amountTF = new JTextField(10);
amountTF.setSize(100,30);
amountTF.setLocation(150,10);

interest = new JLabel("Yearly Interest Rate");
interest.setSize(140,30);
interest.setLocation(10,50);
interestTF = new JTextField(10);
interestTF.setSize(100,30);
interestTF.setLocation(150, 50);

months = new JLabel("Number of Loan Months");
months.setSize(140,30);
months.setLocation(10, 90);
monthsTF = new JTextField(10);
monthsTF.setSize(100,30);
monthsTF.setLocation(150,90);

payment = new JLabel("Amount of Payment");
payment.setSize(140,30);
payment.setLocation(10, 170);
paymentTF = new JTextField(10);
paymentTF.setSize(100,30);
paymentTF.setLocation(150,170);

total = new JLabel("Total Payments");
total.setSize(100,30);
total.setLocation(10, 210);
totalTF = new JTextField(10);
totalTF.setSize(100,30);
totalTF.setLocation(150,210);

//Create Calculate Button
calculate = new JButton("Calculate");
calculate.addActionListener(this);
calculate.setSize(100, 30);
calculate.setLocation(30, 130);

//Create Reset Button
reset = new JButton("Reset");
reset.addActionListener(this);
reset.setSize(100,30);
reset.setLocation(150, 130);

//Place the Componenets in the Pane
c.add(amount);
c.add(amountTF);

c.add(interest);
c.add(interestTF);

c.add(months);
c.add(monthsTF);

c.add(calculate);
c.add(reset);

c.add(payment);
c.add(paymentTF);

c.add(total);
c.add(totalTF);

//Call method addWindowListener using an anonymous class.
this.addWindowListener(new WindowAdapter()
//{
// public void windowClosing(WindowEvent e)
// {
// System.exit(0);
//}
//}
);

//setVisible(true);
} //End of Constructor

public void actionPerformed(ActionEvent e)
{
//Get the string associated with the action being performed.
String str = e.getActionCommand();

//Decide which action to take, based on the first character.
switch(str.charAt(0))
{
case 'C':
//The calculate button was clicked.
evaluate();
break;

case 'R':
//The reset button was pressed.
zero();
break;
}
} // End of method actionPerformed.

private void zero()
{
amountTF.setText("");
interestTF.setText("");
monthsTF.setText("");
paymentTF.setText("");
totalTF.setText("");
} // End of method zero.

private void evaluate()
{
final char beep = '\u0007';
double payAmount;

try
{
double principle = Double.parseDouble(amountTF.getText());
double rate = Double.parseDouble(interestTF.getText());
double time = Double.parseDouble(monthsTF.getText());
payAmount = (principle*rate/12*Math.pow(rate/12+1,time)) /
(Math.pow(rate/12+1,time)-1);
paymentTF.setText(String.format("%.2f", payAmount));
payAmount *= time;
totalTF.setText(String.format("%.2f", payAmount));
}

catch (Exception e)
{
System.out.print(beep);
paymentTF.setText("input ERROR");
}
}

} //End of Applet.

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