Sipping Java

Need help on this working properly... it outputs a wrong result.. is it just the math operation at the bottom? What should the equation read as?

private JButton buttonCalc;

public Calculator() {
initComponents();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
pack();

// Add Listeners
buttonCalc.addActionListener(this);
}

public void initComponents() {
//Initialize Components
panelAdder = new JPanel();
labela = new JLabel("Amount");
textFieldAmount = new JTextField();
labelt = new JLabel("Term");
textFieldTerm = new JTextField();
labelr = new JLabel("Rate");
textFieldRate = new JTextField();
textFieldResult = new JTextField();
buttonCalc = new JButton("Calculate");

//Set Object Attributes
textFieldResult.setEditable(false);
textFieldResult.setColumns(8);
textFieldAmount.setColumns(6);
textFieldTerm.setColumns(2);
textFieldRate.setColumns(2);

Container contentPane = getContentPane();
contentPane.setLayout(new FlowLayout());

//Lets add the components to the panel
panelAdder.add(labela);
panelAdder.add(textFieldAmount);
panelAdder.add(labelt);
panelAdder.add(textFieldTerm);
panelAdder.add(labelr);
panelAdder.add(textFieldRate);
panelAdder.add(buttonCalc);
panelAdder.add(textFieldResult);

contentPane.add(panelAdder);
}

public static void main(String [] args) {
Calculator frame = new Calculator();
}

private void setResultValue() {
double amount = Double.parseDouble (textFieldAmount.getText());
double term = Integer.parseInt(textFieldTerm.getText());
double rate = Double.parseDouble(textFieldRate.getText()) / 100.;
double result = amount * ( rate * Math.pow ( ( 1 + rate ), term ) ) / ( Math.pow( ( 1 + rate ), term ) - 1 );

textFieldResult.setText(Double.toString(result));
}

public void actionPerformed(ActionEvent event) {
System.out.println("Action Button");
String command = event.getActionCommand();
if ("Calculate".equals(command)) { setResultValue(); }
}
}

Actually, there always seems to be a little noise that is enough to prevent me from being able think straight and clear. ugh!

Quite a lot to do with this one.. so Far I have a class that looks like

public class Person
{
private String firstName;
private String lastName;

public Person()
{
firstName = "";
lastName = "";

}

public Person(String first, String last)
{
setName(first, last);
}

public String toString()
{
return (firstName + " " + lastName);
}

public void setName(String first, String last)
{
firstName = first;
lastName = last;
}

public Person setLastName(String last)
{
lastName = last;

return this;
}

public Person setFirstName(String first)
{
firstName = first;

return this;
}

public String getFirstName()
{
return firstName;
}

public String getLastName()
{
return lastName;
}
}

So how would I set the last name only
Check whether a given last name is the same as the last name of this person
Return true if 2 objects contain the same last name (Using equals method)
Use makecopy to copy the instance variables of a Person object into another Person object
Add the copy constructor
Write the definitions of the methods of the class Person to implement the operations for this class

There's some other stuff as well, but I'll forgo mentioning more.

What's wrong with this code?

import java.util.*;

public class Exercise14
{
static Scanner console = new Scanner(System.in);

public static void main(String [] args)
{
int first, third;
IntClass second, fourth;

first = 3;
second = new IntClass(4);
third = 6;
fourth = new IntClass(7);

System.out.println(first + " " + second.getNum()
+ " " + third + " "
+ fourth.getNum());
getData(first, second, third, fourth);
System.out.println(first + " " + second.getNum()
+ " " + third + " "
+ fourth.getNum());
fourth.setNum(first * second.getNum() + third +
fourth.getNum());
getData(third, fourth, first, second);
System.out.println(first + " " + second.getNum()
+ " " + third + " "
+ fourth.getNum());
}

public static void getData(int a, IntClass b, int c, IntClass d)

{
a = console.nextInt();
b.setNum(console.nextInt());
c = console.nextInt();
d.setNum(console.nextInt());

b.setNum(a * b.getNum() - c);
d.setNum(b.getNum() + d.getNum());
}

}

I'm getting this when I compile:

Exercise14.java:32: cannot find symbol
symbol : class IntClass
location: class Exercise14
public static void getData(int a, IntClass b, int c, IntClass d)
^
Exercise14.java:32: cannot find symbol
symbol : class IntClass
location: class Exercise14
public static void getData(int a, IntClass b, int c, IntClass d)
^
Exercise14.java:10: cannot find symbol
symbol : class IntClass
location: class Exercise14
IntClass second, fourth;
^
Exercise14.java:13: cannot find symbol
symbol : class IntClass
location: class Exercise14
second = new IntClass(4);
^
Exercise14.java:15: cannot find symbol
symbol : class IntClass
location: class Exercise14
fourth = new IntClass(7);
^
Exercise14.java:24: operator + cannot be applied to int,IntClass.getNum
fourth.setNum(first * second.getNum() + third +
^
6 errors

----jGRASP wedge2: exit code for process is 1.
----jGRASP: operation complete.

After just trying to compile what I coded, I made what I hope are appropiate changes. . and so now my program looks like . .

import java.io.*;
import java.util.*;
import javax.swing.JOptionPane;

public class PropertyTax
{
public static void main(String [] args)
throws FileNotFoundException
{
String inputAssessedValueString;
double inputAssessedValue;
double taxableAmount;
double taxRate_hundreds;
double finalPropertyTax;

inputAssessedValueString = JOptionPane.showInputDialog
("Enter assessed value");

inputAssessedValue = Double.parseDouble(inputAssessedValueString);

taxableAmount = 0.92 * inputAssessedValue;
taxRate_hundreds = taxableAmount / 100;
finalPropertyTax = taxRate_hundreds * 1.05;

JOptionPane.showMessageDialog(null,
String.format("The Assessed Value equals $ %.2f%n",inputAssessedValue)
+ String.format("Taxable Amount equals $ %.2f%n", taxableAmount)
+ String.format("Tax Rate each $ 100.00: $ 1.05")
+ String.format("Property Tax equals %.2f%n", finalPropertyTax),
"Property Tax Calculation",
JOptionPane.INFORMATION_MESSAGE);

PrintWriter outFile = new PrintWriter("a:\\proptax.txt");

outFile.close();
}
}

Well, your first task could be to come up with a nice object model (on a high, pseudo level).

What object(s) do you think you might need for this task?