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Help; Missing JButtons
Can some one please help me figure out why my JButtons dont show up in my Applet? Every thing compiles and runs fine, but with no buttons
import java.text.*; // Import Text Formatting
import java.text.DecimalFormat;
import java.math.*; //
import java.io.*;
import java.awt.*; // Import Layout
import java.awt.event.*; // Import Event Handlers
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*; // Import GUI Components
public class Mortgage2 extends JApplet
implements ActionListener {
//Declares and builds the variables, labels, fields, and buttons needed for the program
private double AMNT;
private double TERM;
private double APR;
private double PAY;
JLabel Title;
JLabel AMNTLBL;
JLabel TERMLBL;
JLabel APRLBL;
JLabel PAYLBL;
JTextField AMNTFLD;
JTextField TERMFLD;
JTextField APRFLD;
JTextField PAYFLD;
JButton CalculateBTN;
JButton ResetBTN;
public void init()
{
getContentPane().setLayout(null);
setupGUI();
}
void setupGUI()
{
//Builds all labels required
Title = new JLabel();
Title.setLocation(101,4);
Title.setSize(120,32);
Title.setForeground( new Color(-16777216) );
Title.setBackground( new Color(-6710887) );
Title.setText("Mortgage Calculator");
getContentPane().add(Title);
AMNTLBL = new JLabel();
AMNTLBL.setLocation(0,46);
AMNTLBL.setSize(207,32);
AMNTLBL.setForeground( new Color(-16777216) );
AMNTLBL.setBackground( new Color(-6710887) );
AMNTLBL.setText("Enter Loan Amount (Whole Dollars)");
getContentPane().add(AMNTLBL);
TERMLBL = new JLabel();
TERMLBL.setLocation(0,79);
TERMLBL.setSize(207,32);
TERMLBL.setForeground( new Color(-16777216) );
TERMLBL.setBackground( new Color(-6710887) );
TERMLBL.setText("Enter Loans Term (Years)");
getContentPane().add(TERMLBL);
APRLBL = new JLabel();
APRLBL.setLocation(0,112);
APRLBL.setSize(207,32);
APRLBL.setForeground( new Color(-16777216) );
APRLBL.setBackground( new Color(-6710887) );
APRLBL.setText("Enter APR");
getContentPane().add(APRLBL);
PAYLBL = new JLabel();
PAYLBL.setLocation(0,190);
PAYLBL.setSize(207,32);
PAYLBL.setForeground( new Color(-16777216) );
PAYLBL.setBackground( new Color(-6710887) );
PAYLBL.setText("Your Monthly Payment");
getContentPane().add(PAYLBL);
//Builds all text fields required
AMNTFLD = new JTextField();
AMNTFLD.setLocation(227,46);
AMNTFLD.setSize(100,32);
AMNTFLD.setText("");
AMNTFLD.setColumns(10);
getContentPane().add(AMNTFLD);
TERMFLD = new JTextField();
TERMFLD.setLocation(227,79);
TERMFLD.setSize(100,32);
TERMFLD.setText("");
TERMFLD.setColumns(10);
getContentPane().add(TERMFLD);
APRFLD = new JTextField();
APRFLD.setLocation(227,112);
APRFLD.setSize(100,32);
APRFLD.setText("");
APRFLD.setColumns(10);
getContentPane().add(APRFLD);
PAYFLD = new JTextField();
PAYFLD.setLocation(226,190);
PAYFLD.setSize(100,32);
PAYFLD.setText("");
PAYFLD.setColumns(10);
getContentPane().add(PAYFLD);
//Binds labels to fields
AMNTLBL.setLabelFor(AMNTFLD);
TERMLBL.setLabelFor(TERMFLD);
APRLBL.setLabelFor(APRFLD);
PAYLBL.setLabelFor(PAYFLD);
//Builds all buttons required
CalculateBTN = new JButton("Calculate");
CalculateBTN.addActionListener(this);
CalculateBTN.setActionCommand("Calculate");
ResetBTN = new JButton("Reset");
ResetBTN.addActionListener(this);
ResetBTN.setActionCommand("Reset");
//Builds JApplet window
setSize(337,259);
setBackground( new Color(-6710887) );
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals(CalculateBTN.getActio nCommand())) {
try {
AMNT = validateNumber(AMNTFLD.getText(), "Loans Amount");
AMNTFLD.setText(CurrencyComposition(AMNT));
APR = validateNumber(APRFLD.getText(), "APR");
TERM = validateNumber(TERMFLD.getText(), "Loans Term");
double PAY = CalcPAY(AMNT, APR, TERM);
PAYFLD.setText(CurrencyComposition(PAY));
}
catch (Exception t1) {
PAYFLD.setText(null);
};
} else if (e.getActionCommand().equals(ResetBTN.getActionCom mand())) {
AMNTFLD.setText(null);
APRFLD.setText(null);
TERMFLD.setText(null);
PAYFLD.setText(null);
}
}
// Calculates the monthly payment
private double CalcPAY(double AMNT, double APR, double TERM) {
double MAPR = (APR / 100) / 12; // Formula for J
double MTERM = TERM * 12; // Formula for N
double PAY = AMNT * (MAPR / (1 - Math.pow((1 + MAPR), -TERM)));
return PAY;
}
private double validateNumber(String numericString, String fieldName) throws Exception {
double numberValue = 0;
try {
// make sure we have a number
if (numericString.isEmpty())
throw new Exception();
// strip out currency symbol
if (numericString.indexOf('$')> -1)
{
String newString = numericString.replace("$","");
numericString = newString;
}
// transform string into double
numberValue = NumberFormat.getNumberInstance().parse(numericStri ng).doubleValue();
// no negative numbers
if (numberValue < 0)
throw new Exception();
} catch (Exception e) {
// Display Error Message in it's own pane
JOptionPane.showMessageDialog(this, "Invalid value in " + fieldName + ". \nPlease check your entry.", "Data Entry Error", JOptionPane.ERROR_MESSAGE);
throw e;
}
return numberValue;
}
// Formats the numeric values to readable currency
private String CurrencyComposition(double input) {
DecimalFormat df = new DecimalFormat("$###,###,###.00");
df.setMaximumFractionDigits(2);
String formattedString = df.format(input);
return formattedString;
}
}
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I figured out my issue with the buttons, but I am pretty sure my equation for loan calculations is wrong.... Please help if you want.
import java.text.; // Import Text Formatting
import java.text.DecimalFormat;
import java.math.; //
import java.io.;
import java.awt.; // Import Layout
import java.awt.event.; // Import Event Handlers
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.; // Import GUI Components
public class Mortgage2 extends JApplet
implements ActionListener {
//Declares and builds the variables, labels, fields, and buttons needed for the program
private double AMNT;
private double TERM;
private double APR;
private double PAY;
JLabel Title;
JLabel AMNTLBL;
JLabel TERMLBL;
JLabel APRLBL;
JLabel PAYLBL;
JTextField AMNTFLD;
JTextField TERMFLD;
JTextField APRFLD;
JTextField PAYFLD;
JButton CalculateBTN;
JButton ResetBTN;
public void init()
{
getContentPane().setLayout(null);
setupGUI();
}
void setupGUI()
{
//Builds all labels required
Title = new JLabel();
Title.setLocation(101,4);
Title.setSize(120,32);
Title.setForeground( new Color(-16777216) );
Title.setBackground( new Color(-6710887) );
Title.setText("Mortgage Calculator");
getContentPane().add(Title);
AMNTLBL = new JLabel();
AMNTLBL.setLocation(0,46);
AMNTLBL.setSize(207,32);
AMNTLBL.setForeground( new Color(-16777216) );
AMNTLBL.setBackground( new Color(-6710887) );
AMNTLBL.setText("Enter Loan Amount (Whole Dollars)");
getContentPane().add(AMNTLBL);
TERMLBL = new JLabel();
TERMLBL.setLocation(0,79);
TERMLBL.setSize(207,32);
TERMLBL.setForeground( new Color(-16777216) );
TERMLBL.setBackground( new Color(-6710887) );
TERMLBL.setText("Enter Loans Term (Years)");
getContentPane().add(TERMLBL);
APRLBL = new JLabel();
APRLBL.setLocation(0,112);
APRLBL.setSize(207,32);
APRLBL.setForeground( new Color(-16777216) );
APRLBL.setBackground( new Color(-6710887) );
APRLBL.setText("Enter APR");
getContentPane().add(APRLBL);
PAYLBL = new JLabel();
PAYLBL.setLocation(0,190);
PAYLBL.setSize(207,32);
PAYLBL.setForeground( new Color(-16777216) );
PAYLBL.setBackground( new Color(-6710887) );
PAYLBL.setText("Your Monthly Payment");
getContentPane().add(PAYLBL);
//Builds all text fields required
AMNTFLD = new JTextField();
AMNTFLD.setLocation(227,46);
AMNTFLD.setSize(100,32);
AMNTFLD.setText("");
AMNTFLD.setColumns(10);
getContentPane().add(AMNTFLD);
TERMFLD = new JTextField();
TERMFLD.setLocation(227,79);
TERMFLD.setSize(100,32);
TERMFLD.setText("");
TERMFLD.setColumns(10);
getContentPane().add(TERMFLD);
APRFLD = new JTextField();
APRFLD.setLocation(227,112);
APRFLD.setSize(100,32);
APRFLD.setText("");
APRFLD.setColumns(10);
getContentPane().add(APRFLD);
PAYFLD = new JTextField();
PAYFLD.setLocation(226,190);
PAYFLD.setSize(100,32);
PAYFLD.setText("");
PAYFLD.setColumns(10);
getContentPane().add(PAYFLD);
//Binds labels to fields
AMNTLBL.setLabelFor(AMNTFLD);
TERMLBL.setLabelFor(TERMFLD);
APRLBL.setLabelFor(APRFLD);
PAYLBL.setLabelFor(PAYFLD);
//Builds all buttons required
CalculateBTN = new JButton("Calculate");
CalculateBTN.setLocation(29,150);
CalculateBTN.setSize(100,32);
getContentPane().add(CalculateBTN);
CalculateBTN.addActionListener(this);
CalculateBTN.setActionCommand("Calculate");
ResetBTN = new JButton("Reset");
ResetBTN.setLocation(200,150);
ResetBTN.setSize(100,32);
getContentPane().add(ResetBTN);
ResetBTN.addActionListener(this);
ResetBTN.setActionCommand("Reset");
//Builds JApplet window
setSize(337,259);
setBackground( new Color(-6710887) );
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals(CalculateBTN.getActio nCommand())) {
try {
AMNT = validateNumber(AMNTFLD.getText(), "Loans Amount");
AMNTFLD.setText(CurrencyComposition(AMNT));
APR = validateNumber(APRFLD.getText(), "APR");
TERM = validateNumber(TERMFLD.getText(), "Loans Term");
double PAY = CalcPAY(AMNT, APR, TERM);
PAYFLD.setText(CurrencyComposition(PAY));
}
catch (Exception t1) {
PAYFLD.setText(null);
};
} else if (e.getActionCommand().equals(ResetBTN.getActionCom mand())) {
AMNTFLD.setText(null);
APRFLD.setText(null);
TERMFLD.setText(null);
PAYFLD.setText(null);
}
}
// Calculates the monthly payment
private double CalcPAY(double AMNT, double APR, double TERM) {
double MAPR = (APR / 100) / 12; // Formula for J
double MTERM = TERM 12; // Formula for N
double PAY = AMNT (MAPR / (1 - Math.pow((1 MAPR), -TERM)));
return PAY;
}
private double validateNumber(String numericString, String fieldName) throws Exception {
double numberValue = 0;
try {
// make sure we have a number
if (numericString.isEmpty())
throw new Exception();
// strip out currency symbol
if (numericString.indexOf('$')> -1)
{
String newString = numericString.replace("$","");
numericString = newString;
}
// transform string into double
numberValue = NumberFormat.getNumberInstance().parse(numericStri ng).doubleValue();
// no negative numbers
if (numberValue < 0)
throw new Exception();
} catch (Exception e) {
// Display Error Message in it's own pane
JOptionPane.showMessageDialog(this, "Invalid value in " fieldName + ". \nPlease check your entry.", "Data Entry Error", JOptionPane.ERROR_MESSAGE);
throw e;
}
return numberValue;
}
// Formats the numeric values to readable currency
private String CurrencyComposition(double input) {
DecimalFormat df = new DecimalFormat("$###,###,###.00");
df.setMaximumFractionDigits(2);
String formattedString = df.format(input);
return formattedString;
}
}
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You never add the buttons to anything.
By the way you should get into the habit of starting variable names with a lower case letter and using camelCase. ALLCAPS has a meaning that you don't intend.
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