I would like to be able to divide this java code up into more than one file, so I can reuse the code for other programs, but I'm not sure what I can grab.
Right now, I can't make another program using this code, as you see the WHOLE program is in this file alone, what can I do?
package usefulapps;
/*
File: MortgageCalculator3.java
This file calculates the monthly payments of a user inputs for a mortgage.
*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
@SuppressWarnings("serial")
public class MortgageCalculator3 extends JFrame implements ActionListener
{
// Getting the year, then parsing it so I can manipulate it as an integer
Date thisYear = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy");
String y = formatter.format(thisYear);
int getYear = Integer.parseInt(y);
//*******
int financeYears;
double interestRate;
int salary;
double loan;
double rate;
double yearlyPmt;
double[] monthlyPmt, principal, loanPmt, ratePmt, newPrincipal, interestPerYear;
double interest;
double endPrincipal;
boolean calculate = false;
boolean next = false;
boolean previous = false;
//variables
int yearNumber;
int periodNumber = 1;
int month = 0;
int currMonth = 0;
DecimalFormat df = new DecimalFormat("###,###.00");
//layout preparation
LoanLayout customLayout = new LoanLayout();
JLabel loanLabel = new JLabel("Loan Amount");
JTextField loanText = new JTextField();
JLabel termLabel = new JLabel("Years Financed");
JTextField termText = new JTextField();
JLabel rateLabel = new JLabel("Interest Rate (x.xx)");
JTextField rateText = new JTextField();
JLabel salaryLabel = new JLabel("Annual Salary");
JTextField salaryText = new JTextField();
JLabel monthlyLabel = new JLabel("Monthly Payment");
JTextField monthlyText = new JTextField();
JLabel yearTotalLabel = new JLabel("Year Total");
JTextField yearTotalText = new JTextField();
JLabel salaryTaxLabel = new JLabel("Salary After Taxes");
JTextField salaryTaxText = new JTextField();
JLabel salPercentLabel = new JLabel("Salary Percent of Yearly Mortgage");
JTextField salPercentText = new JTextField();
JLabel scheduleLabel = new JLabel("Schedule");
JTextArea scheduleText = new JTextArea();
JScrollPane scroller = new JScrollPane(scheduleText);
public MortgageCalculator3()
{
JButton calcButton = new JButton("Calculate");
JButton resetButton = new JButton("Reset");
JButton scheduleButton = new JButton("Show Schedule");
JButton previousButton = new JButton("<< Previous Year");
JButton nextButton = new JButton("Next Year >>");
JButton exitButton = new JButton("Exit");
//add ActionListener to buttons
calcButton.addActionListener(this);
resetButton.addActionListener(this);
scheduleButton.addActionListener(this);
previousButton.addActionListener(this);
nextButton.addActionListener(this);
exitButton.addActionListener(this);
//add ActionCommand to buttons
calcButton.setActionCommand("calculate");
resetButton.setActionCommand("reset");
scheduleButton.setActionCommand("show");
previousButton.setActionCommand("previous");
nextButton.setActionCommand("next");
exitButton.setActionCommand("exit");
//getContentPane, set editable & setText for all labels, fields, and buttons
Container pane = getContentPane();
pane.setLayout(customLayout);
pane.add(loanLabel);
pane.add(loanText);
pane.add(termLabel);
pane.add(termText);
pane.add(rateLabel);
pane.add(rateText);
pane.add(salaryLabel);
pane.add(salaryText);
pane.add(calcButton);
pane.add(resetButton);
pane.add(monthlyLabel);
pane.add(monthlyText);
monthlyText.setEditable(false);
pane.add(yearTotalLabel);
pane.add(yearTotalText);
yearTotalText.setEditable(false);
pane.add(salaryTaxLabel);
pane.add(salaryTaxText);
salaryTaxText.setEditable(false);
pane.add(salPercentLabel);
pane.add(salPercentText);
pane.add(scheduleButton);
salPercentText.setEditable(false);
pane.add(scheduleLabel);
pane.add(scroller);
scheduleText.setEditable(false);
pane.add(previousButton);
pane.add(nextButton);
pane.add(exitButton);
//added this to ensure that the Frame closes properly
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
);
}
//actionPerformed
public void actionPerformed(ActionEvent e)
{
String arg = e.getActionCommand();
if (arg == "calculate" )
{
if (next)
getYear = getYear - yearNumber + 1;
next = false;
interest = 0;
scheduleText.setText("");
try
{
loan = Double.parseDouble(loanText.getText());
financeYears = Integer.parseInt(termText.getText());
rate = Double.parseDouble(rateText.getText());
salary = Integer.parseInt(salaryText.getText());
}
catch (Exception ex)
{
JOptionPane.showMessageDialog(null, "Invalid mortgage, term, rate, or salary amount\nFill out all above fields","Error", JOptionPane.ERROR_MESSAGE);
return;
}
calculate = true;
rate = rate / 100;
endPrincipal = loan;
DecimalFormat df1 = new DecimalFormat("###,###.000");
monthlyPmt = new double[(int) (12 * financeYears + 1)];
principal = new double[(int) (12 * financeYears + 1)];
interestPerYear = new double[financeYears];
for (int i = 0; i < monthlyPmt.length; i++)
{
principal[i] = loan;
monthlyPmt[i] = (double) Math.round((rate / 12 * principal[i] * (Math.pow(1 + rate / 12,financeYears * 12)))/(Math.pow((1 + rate / 12),financeYears * 12) -1) * 100) / 100;
yearlyPmt = (monthlyPmt[i] * 12);
}
int[] bracketRange = {0, 8375, 34000, 82400, 171850, 373650};
double[] taxBracket = {0.90, 0.85, 0.75, 0.72, 0.67, 0.65}; //10%, 15%, 25%, 28%, 33%, 35%
double afterTaxes = 0;
double salaryPercent = 0;
if (salary >= bracketRange[5])
{
salaryPercent = (yearlyPmt / (salary * taxBracket[5] / 100));
afterTaxes = salary * taxBracket[5];
}
for (int x = 4, y = 5; x > -1 && y > 0; x--, y--)
{
if (salary >= bracketRange[x] && salary < bracketRange[y])
{
salaryPercent = (yearlyPmt / (salary * taxBracket[x] / 100));
afterTaxes = salary * taxBracket[x];
}
}
monthlyText.setText("$" + df.format(monthlyPmt[0]));
yearTotalText.setText("$" + df.format(yearlyPmt));
salaryTaxText.setText("$" + df.format(afterTaxes));
salPercentText.setText(df1.format(salaryPercent) + "%");
createSchedule(monthlyPmt, principal, financeYears, rate);
}
//if reset button is picked, fields are cleared.
if (arg == "reset")
{
calculate = false;
loanText.setText("");
termText.setText("");
rateText.setText("");
salaryText.setText("");
monthlyText.setText("");
yearTotalText.setText("");
salaryTaxText.setText("");
salPercentText.setText("");
scheduleText.setText("");
}
//if show button is picked, year 1 is shown in the schedule area
if (arg == "show")
{
if (calculate)
{
yearNumber = 1;
populateSchedule(yearNumber);
}
calculate = false;
}
//if previous button is picked, schedule goes back 1 year
if (arg == "previous")
{
previous = true;
if (yearNumber > 1)
{
yearNumber--;
getYear--;
populateSchedule(yearNumber);
}
}
//if next button is picked, schedule goes forward 1 year
if (arg == "next")
{
next = true;
if (yearNumber < financeYears)
{
yearNumber++;
getYear++;
populateSchedule(yearNumber);
}
}
//if exit button is picked, program closes
if (arg == "exit")
{
System.exit(0);
}
}
public static void main(String[] args)
{
//creating the JFrame window
{
new MortgageCalculator3();
JFrame nFrame = new MortgageCalculator3();
nFrame.setVisible(true);
nFrame.setTitle("Mortgage Calculator");
nFrame.setSize(650,770);
nFrame.setLocation(600,200);
}
}
public void createSchedule(double monthlyPmt[], double principal[], double financeYears, double rate)
{
loanPmt = new double[(int) (12 * financeYears + 1)];
ratePmt = new double[(int) (12 * financeYears + 1)];
newPrincipal = new double[(int) (12 * financeYears + 1)];
for (yearNumber = 1; yearNumber <= financeYears; yearNumber++)
{
for (int periodNumber = 1; periodNumber <= 12; periodNumber++)
{
month = (12 * (yearNumber - 1)) + periodNumber - 1;
ratePmt[month] = (double) Math.round((principal[month] * rate / 12) * 100) / 100;
loanPmt[month] = (double) Math.round((monthlyPmt[month] - ratePmt[month]) * 100) / 100;
newPrincipal[month] = (double) Math.round((principal[month] - loanPmt[month]) * 100) / 100;
principal[month + 1] = newPrincipal[month];
interest += ratePmt[month];
}
principal[month + 1] = newPrincipal[month];
interestPerYear[yearNumber - 1] = interest;
}
}
public void populateSchedule(int yearNumber) // Places the values for a given year of the loan into the schedule
{
if (yearNumber >= 10)
scheduleText.setText("\t\t Year " + yearNumber + " - " + getYear + "\n\t\t ********");
else
scheduleText.setText("\t\t Year " + yearNumber + " - " + getYear + "\n\t\t ********");
scheduleText.append("\nMONTH\tBEG BALANCE\tLOAN\tINTEREST\tPAYMENT\tEND BALANCE");
for (int periodNumber = 1; periodNumber <= 12; periodNumber++)
{
currMonth = 12 * (yearNumber - 1) + periodNumber - 1;
//for last few payments, so the balance doesn't go in the negative
if (newPrincipal[currMonth] < 0)
{
newPrincipal[currMonth] = 0;
loanPmt[currMonth] = principal[currMonth] - ratePmt[currMonth];
monthlyPmt[currMonth] = loanPmt[currMonth] + ratePmt[currMonth];
}
scheduleText.append("\n" + (currMonth + 1) + "\t$" + (df.format(principal[currMonth])) + " \t$" + (df.format(loanPmt[currMonth])) + "\t$" + (df.format(ratePmt[currMonth])) + "\t$" + (df.format(monthlyPmt[currMonth])) + "\t$" + (df.format(newPrincipal[currMonth])));
principal[currMonth + 1] = newPrincipal[currMonth];
}
if (yearNumber < financeYears)
scheduleText.append("\n\nTotal interest paid so far is: $" + df.format(interestPerYear[yearNumber - 1]));
else
{
scheduleText.append("\n\nTotal interest paid: $" + df.format(interestPerYear[yearNumber - 1]));
scheduleText.append("\nTotal cost of home: $" + df.format(endPrincipal + interestPerYear[yearNumber - 1]) + " after " + (yearNumber) + " years");
}
}
//Layout manager
class LoanLayout implements LayoutManager
{
public LoanLayout()
{
}
public void addLayoutComponent(String name, Component comp)
{
}
public void removeLayoutComponent(Component comp)
{
}
// layout dimensions
public Dimension preferredLayoutSize(Container parent)
{
Dimension dim = new Dimension(0, 0);
Insets insets = parent.getInsets();
dim.height = 770 + insets.top + insets.bottom; //height of window
dim.width = 650 + insets.left + insets.right; // width of window
return dim;
}
public Dimension minimumLayoutSize(Container parent)
{
Dimension dim = new Dimension(0, 0);
return dim;
}
// arrangement of all components (JButton, JTextField, and JLabel) in window as listed above
public void layoutContainer(Container parent)
{
Insets insets = parent.getInsets();
Component w = parent.getComponent(0); // array for components (JButton, JTextField, and JLabel)
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+20,130,20);} //loan label
w = parent.getComponent(1);
if (w.isVisible()) {w.setBounds(insets.left+170,insets.top+20,100,20);} // loan field
w = parent.getComponent(2);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+50,130,20);} // term label
w = parent.getComponent(3);
if (w.isVisible()) {w.setBounds(insets.left+170,insets.top+50,100,20);} // term field
w = parent.getComponent(4);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+80,130,20);} // rate label
w = parent.getComponent(5);
if (w.isVisible()) {w.setBounds(insets.left+170,insets.top+80,100,20);} // rate field
w = parent.getComponent(6);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+110,160,20);} // salary label
w = parent.getComponent(7);
if (w.isVisible()) {w.setBounds(insets.left+170,insets.top+110,100,20);} // salary field
w = parent.getComponent(8);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+150,120,30);} // calculate button
w = parent.getComponent(9);
if (w.isVisible()) {w.setBounds(insets.left+150,insets.top+150,100,30);} // reset button
w = parent.getComponent(10);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+200,140,20);} // payment label
w = parent.getComponent(11);
if (w.isVisible()) {w.setBounds(insets.left+170,insets.top+200,100,20);} // payment field
w = parent.getComponent(12);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+230,140,20);} // yearTotal label
w = parent.getComponent(13);
if (w.isVisible()) {w.setBounds(insets.left+170,insets.top+230,100,20);} // yearTotal field
w = parent.getComponent(14);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+260,140,20);} // salaryTax label
w = parent.getComponent(15);
if (w.isVisible()) {w.setBounds(insets.left+170,insets.top+260,100,20);} // salaryTax field
w = parent.getComponent(16);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+290,210,20);} // salPercent label
w = parent.getComponent(17);
if (w.isVisible()) {w.setBounds(insets.left+240,insets.top+290,80,20);} // salPercent field
w = parent.getComponent(18);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+320,200,30);} // show button
w = parent.getComponent(19);
if (w.isVisible()) {w.setBounds(insets.left+285,insets.top+340,80,20);} // schedule label
w = parent.getComponent(20);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+370,610,300);} // schedule field
w = parent.getComponent(21);
if (w.isVisible()) {w.setBounds(insets.left+20,insets.top+680,150,30);} // previous button
w = parent.getComponent(22);
if (w.isVisible()) {w.setBounds(insets.left+480,insets.top+680,150,30);} // next button
w = parent.getComponent(23);
if (w.isVisible()) {w.setBounds(insets.left+285,insets.top+690,80,50);} // exit button
}
}
}
