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Write the program in Java (with a graphical user interface) and have it calculate and display the mortgage payment amount from user input of the amount of the mortgage and the user's selection from a menu of available mortgage loans:
7 years at 5.35%
15 years at 5.5%
30 years at 5.75%
Use an array for the mortgage data for the different loans. Read the interest rates to fill the array from a sequential file. Display the mortgage payment amount followed by the loan balance and interest paid for each payment over the term of the loan. Add graphics in the form of a chart. Allow the user to loop back and enter a new amount and make a new selection or quit. Please insert comments in the program to document the program. Here is what I have thus far:
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import javax.swing.*;
import javax.swing.text.*;
import java.lang.Double.*;
public class MortPayment_v3 extends Frame implements ActionListener
{
//declare an array for buttons
private Button buttons[];
//declare panels for window layout
private Panel fieldsPanel, buttonPanel, labelsPanel, displayPanel;
//Create Variables
private static double LoanAmt=0.0;
private static double MonthlyPayment=0.0;
private static double InterestRate=0.0;
private static int Duration=0;
//Clear Fields
private boolean clearText=true;
String selection=("");
//Create Array
double[][] availLoans={{LoanAmt, 5.35, 7.00},{LoanAmt, 5.5, 15.00},{LoanAmt, 5.75, 30.00}};
//Format for 2 decimal places
DecimalFormat pmtPattern=new DecimalFormat("##,###,###.00");
DecimalFormat dmlPattern=new DecimalFormat("#.####");
DecimalFormat intRatePattern=new DecimalFormat("##.###%");
DecimalFormat durPattern=new DecimalFormat("## yrs");
private JLabel LoanAmtLabel; //declare label for Mortgage Amount field
private JLabel LoanSelectionMenuLabel; //declare label for Loan Selection menu
private JLabel MonthlyPaymentLabel; //declare label for Monthly Payment field
private static String LoanAmtString=(" Enter the Amount of Mortgage Here: "); //declare text for Loan Amount label
private static String LoanSelectionString=(" Select the Term and Interest Rate: "); //declare text for Loan Selection menu
private static String MonthlyPaymentString=(" Your Monthly Payment: ");//declare text for Monthly Payment label
private static String AvailLoan1=("7 yrs @ 5.35%"); //declare first available loan for menu
private static String AvailLoan2=("15 yrs @ 5.5%"); //declare second available loan for menu
private static String AvailLoan3=("30 yrs @ 5.75%"); //declare third available loan for menu
private static String Balance=("Loan Balance "); //declare string for Loan Balance column of Display Field
private static String IntPaid=(" Interest Paid"); //declare string for Interest Paid column of Display Field
private TextField LoanAmtField;
private TextField MonthlyPaymentField;
private TextArea DisplayTextArea;
Choice LoanSelectionMenu=new Choice();
public MortPayment_v3()
{
//create labels for Frame
LoanAmtLabel=new JLabel(LoanAmtString);
LoanSelectionMenuLabel=new JLabel(LoanSelectionString);
MonthlyPaymentLabel=new JLabel(MonthlyPaymentString);
//Set labels to textfield
LoanAmtLabel.setLabelFor(LoanAmtField);
LoanSelectionMenuLabel.setLabelFor(LoanSelectionMenu);
MonthlyPaymentLabel.setLabelFor(MonthlyPaymentField);
LoanAmtField=new TextField(10);
LoanAmtField.setEditable(true);
MonthlyPaymentField=new TextField(10);
MonthlyPaymentField.setEditable(false);
DisplayTextArea = new TextArea (4,25);
DisplayTextArea.setEditable(false);
//construct panel
fieldsPanel=new Panel();
buttonPanel=new Panel();
buttons=new Button[3];
labelsPanel=new Panel();
displayPanel=new Panel();
//construct buttons
buttons[0]=new Button("Calculate Payment"); //Calculate Monthly Payment
buttons[1]=new Button("Reset"); //Start Over
buttons[2]=new Button("Exit Program"); //Exit program
//Frame and Panel layouts
setLayout (new BorderLayout());
fieldsPanel.setLayout(new GridLayout(4,1,20,15));
buttonPanel.setLayout(new GridLayout(1,3,5,5));
labelsPanel.setLayout(new GridLayout(4,1,10,10));
displayPanel.setLayout(new GridLayout(1,1,0,0));
fieldsPanel.add(LoanAmtField);
fieldsPanel.add(LoanSelectionMenu);
LoanSelectionMenu.addItem(AvailLoan1);
LoanSelectionMenu.addItem(AvailLoan2);
LoanSelectionMenu.addItem(AvailLoan3);
fieldsPanel.add(MonthlyPaymentField);
buttonPanel.add(buttons[0]);
buttonPanel.add(buttons[1]);
buttonPanel.add(buttons[2]);
labelsPanel.add(LoanAmtLabel);
labelsPanel.add(LoanSelectionMenuLabel);
labelsPanel.add(MonthlyPaymentLabel);
displayPanel.add(DisplayTextArea);
//add ActionListener to the buttons
buttons[0].addActionListener(this);
buttons[1].addActionListener(this);
buttons[2].addActionListener(this);
//Adding the Layout
add(fieldsPanel, BorderLayout.CENTER);
add(buttonPanel, BorderLayout.SOUTH);
add(labelsPanel, BorderLayout.WEST);
add(displayPanel, BorderLayout.EAST);
addWindowListener(
new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
//exit program
System.exit(0);
}
}
);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == buttons[0])
{
selection=LoanSelectionMenu.getSelectedItem();
if(selection.equals("7 yrs @ 5.35%"))
{
LoanAmt=new Double(LoanAmtField.getText().trim()).doubleValue();//parse LoanAmt to double
InterestRate=availLoans[0][1];
int Duration=(int)availLoans[0][2]*12; //convert Duration to int (& months) for calculation
double PeriodicInterestRate=(availLoans[0][1]/(12*100)); //declare periodic interest rate for formula
calcMonthlyPayment(LoanAmt, PeriodicInterestRate, Duration);
}
if(selection.equals("15 yrs @ 5.5%"))
{
LoanAmt=new Double(LoanAmtField.getText().trim()).doubleValue();//parse LoanAmt to double
InterestRate=availLoans[1][1];
int Duration=(int)availLoans[1][2]*12; //convert Duration to int (& months) for calculation
double PeriodicInterestRate=(availLoans[1][1]/(12*100)); //declare periodic interest rate for formula
calcMonthlyPayment(LoanAmt, PeriodicInterestRate, Duration);
}
if(selection.equals("30 yrs @ 5.75%"))
{
LoanAmt=new Double(LoanAmtField.getText().trim()).doubleValue();//parse LoanAmt to double
InterestRate=availLoans[2][1];
int Duration=(int)availLoans[2][2]*12; //convert Duration to int (& months) for calculation
double PeriodicInterestRate=(availLoans[2][1]/(12*100)); //declare periodic interest rate for formula
calcMonthlyPayment(LoanAmt, PeriodicInterestRate, Duration);
}
}
else if(e.getSource() == buttons[1])
{
clearText=true; //set clear text flag to true for new calculation
LoanAmtField.setText(""); //set text field to null string (clear)
MonthlyPaymentField.setText(""); //set text field to null string (clear)
// DisplayField.setText(""); //set text field to null string (clear)
DisplayTextArea.setText("");
LoanAmtField.requestFocus(); //return cursor to LoanAmt field
}
else if(e.getSource() == buttons[2])
{
System.exit(0);
}
}
private void calcMonthlyPayment(double LoanAmt, double PeriodicInterestRate, int Duration)
{
//calculate Monthly Payment
MonthlyPayment=(LoanAmt*PeriodicInterestRate)/(1-Math.pow(1+PeriodicInterestRate,-Duration));
LoanAmtField.setText(pmtPattern.format(LoanAmt));
MonthlyPaymentField.setText(pmtPattern.format(MonthlyPayment));
DisplayTextArea.append(Balance + IntPaid + "\n");
double LoanBalance=LoanAmt;
double Interest=0.0;
double MonthlyInterest=0.0;
int PaymentNumber=0;
do
{//Start do/while loop
PaymentNumber++;
MonthlyInterest=LoanBalance*PeriodicInterestRate;
Interest+=MonthlyInterest;
LoanBalance -=MonthlyPayment-MonthlyInterest;
DisplayTextArea.append(pmtPattern.format(LoanBalance)+" "+pmtPattern.format(Interest)+"\n");
System.out.println("After payment "+PaymentNumber+": Loan Balance = "+pmtPattern.format(LoanBalance)+"\tInterest to Date = "+pmtPattern.format(Interest));
} while(PaymentNumber<Duration);
}
public static void main(String[] args)
{
MortPayment_v3 frame=new MortPayment_v3();
frame.setTitle("Mortgage Calculator by M.Nunez ");
frame.setBounds(200,200,600,200);
frame.setVisible(true);
}
}
I also have a bar chart that I would like to implement into this program but lack the knowledge of how to implement this code into my working mortgage calculator. Please help me!!!!
// Program draws a bar chart.
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*; //for the class Rectangle2D
import javax.swing.*;
public class DrawBarChart extends JFrame
{
//to store the sales of four quarters, and the max among them
private double one, two, three, four, max;
// constructor prompts the users for the sales of four quarters
public DrawBarChart()
{
//set title for the window
super( "Bar Graph Drawing" );
String input = ""; //store the input values
// reads the sales of first quarter
input = JOptionPane.showInputDialog(
this, "Enter sales in the first quarter:" );
//need to convert to numeric value for calculation
one = Double.parseDouble( input );
// reads the sales of second quarter
input = JOptionPane.showInputDialog(
this, "Enter sales in the second quarter:" );
//need to convert to numeric value for calculation
two = Double.parseDouble( input );
// reads the sales of third quarter
input = JOptionPane.showInputDialog(
this, "Enter sales in the third quarter:" );
//need to convert to numeric value for calculation
three = Double.parseDouble( input );
// reads the sales of fourth quarter
input = JOptionPane.showInputDialog(
this, "Enter sales in the fourth quarter:" );
//need to convert to numeric value for calculation
four = Double.parseDouble( input );
// find the maximum
max = ( one > two ? one : two );
max = ( max > three ? max : three );
max = ( max > four ? max : four );
// set the size of the window and let it be visible
setSize( 350, 450 );
setVisible( true );
}
// Draw bars of the chart
// scale each bar by the maximum value
// The method 'paint' will be executed right away after the constructor.
public void paint( Graphics g )
{
super.paint( g );
// creates a 2D object to draw
Graphics2D g2d = ( Graphics2D )g;
// set color and draw the bar for the first quarter sales
g2d.setColor( Color.red );
g2d.fill( new Rectangle2D.Double( 25, 250 - 200 *
one / max, 50, 200 * one / max ) );
// set color and draw the bar for the second quarter sales
g2d.setColor( Color.blue );
g2d.fill( new Rectangle2D.Double( 100, 250 - 200 *
two / max, 50, 200 * two / max ) );
// set color and draw the bar for the third quarter sales
g2d.setColor( Color.green );
g2d.fill( new Rectangle2D.Double( 175, 250 - 200 *
three / max, 50, 200 * three / max ) );
// set color and draw the bar for the fourth quarter sales
g2d.setColor( Color.yellow );
g2d.fill( new Rectangle2D.Double( 250, 250 - 200 *
four / max, 50, 200 * four / max ) );
// set the legends of the bar chart
g2d.setColor( Color.black );
g2d.drawString("Legend: ", 20, 280);
g2d.setColor( Color.red );
g2d.fillRect(170, 300, 50, 10);
g2d.setColor( Color.black );
g2d.drawString("First Quarter: " + one, 20, 310);
g2d.setColor( Color.blue );
g2d.fillRect(170, 330, 50, 10);
g2d.setColor( Color.black );
g2d.drawString("Second Quarter: " + two, 20, 340);
g2d.setColor( Color.green );
g2d.fillRect(170, 360, 50, 10);
g2d.setColor( Color.black );
g2d.drawString("Third Quarter: " + three, 20, 370);
g2d.setColor( Color.yellow );
g2d.fillRect(170, 390, 50, 10);
g2d.setColor( Color.black );
g2d.drawString("Fourth Quarter: " + four, 20, 400);
}
public static void main( String args[] )
{
//create an object with type "DrawBarChart", so the constructor
//of the class will be called
DrawBarChart bar = new DrawBarChart();
bar.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
bar.setResizable(false);
}
}
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