I will show you today a Java program used to convert money currency. I made this with a GUI interface using Swing in Java as shown below.
The Design:
Here, the user can convert one currency to other by selecting first a choice or option by clicking the first combo box then the second combo box for the currency to be converted. (see the image below)
As you can see, the user wants to convert from US Dollar currency to Philippine Peso.
After, you select the currency you want to convert, then it's time to enter the amount to convert by inputting or entering it in the text field or text box. (see the image below)
Now, to compute the total amount, you should click the "Compute" button. The total amount converted will be displayed in the second text box which is not editable. I set not editable in the sense the user cannot edit or change the value of this. (see the image below)
Finally, the user can also convert other currencies available from those 2 combo boxes and enter new amount to convert. Now if the you want to quit the program, you can do this by clicking the exit button. Here, the program will asked you if you really want to exit or not. (see the image below)
If the user click the "Yes" button then the program will definitely terminated.
The Program Source Code:
Here is the free source code of the program. Try it and see the the difference.
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
public class CurrencyConverter extends Frame implements ItemListener, ActionListener
{
//iniatialized all the GUI components
JComboBox convertFrom, convertTo;
JTextField txtFrom, txtTo;
JButton compute, exit;
JLabel from, to;
JLabel lblFrom, lblTo;
JPanel mainPanel = new JPanel();
double input = 0;
double result = 0;
public CurrencyConverter() {
//add all the GUI components
super("Money Currency Converter v.1.0");
setSize(420,300);
setLayout(null);
setBackground(Color.lightGray);
lblFrom = new JLabel("From:");
lblFrom.setBounds(30,45,250,30);
lblFrom.setForeground(Color.RED);
add(lblFrom);
convertFrom = new JComboBox();
convertFrom.setBounds(30,70,150,30);
convertFrom.addItem("US Dollar");
convertFrom.addItem("Philippine Peso");
convertFrom.addItem("Japan Yen");
convertFrom.addItem("Thai Baht");
convertFrom.addItem("Taiwan Dollar");
add(convertFrom);
lblTo = new JLabel("To:");
lblTo.setBounds(230,45,250,30);
lblTo.setForeground(Color.RED);
add(lblTo);
convertTo = new JComboBox();
convertTo.setBounds(230,70,150,30);
convertTo.addItem("US Dollar");
convertTo.addItem("Philippine Peso");
convertTo.addItem("Japan Yen");
convertTo.addItem("Thai Baht");
convertTo.addItem("Taiwan Dollar");
add(convertTo);
from = new JLabel("Enter Amount to Convert:");
from.setBounds(50,110,300,30);
add(from);
txtFrom = new JTextField(15);
txtFrom.setBounds(50,140,300,30);
add(txtFrom);
compute = new JButton("Compute");
compute.setBounds(100,250,100,30);
add(compute);
to = new JLabel("Total Amount Converted:");
to.setBounds(50,170,300,30);
add(to);
txtTo = new JTextField(15);
txtTo.setBounds(50,200,300,30);
txtTo.setEditable(false);
txtTo.setForeground(Color.RED);
add(txtTo);
exit = new JButton("Exit");
exit.setBounds(210,250,100,30);
add(exit);
//register all the GUI components who will listen or invoke the methods
convertFrom.addItemListener(this);
convertTo.addItemListener(this);
compute.addActionListener(this);
txtFrom.addActionListener(this);
exit.addActionListener(this);
//this will close the applet window if the user clicked the close or exit button
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
exit();
}
});
}
//the exit method
public void exit(){
setVisible(false);
dispose();
System.exit(0);
}
//show or make the applet window frame visible
public static void main(String args[]) {
CurrencyConverter w = new CurrencyConverter();
w.setVisible(true);
}
public void ConvertDollar() {
if(convertTo.getSelectedItem()=="US Dollar")
{
result = (input);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Philippine Peso")
{
result = (input * 43.8);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Japan Yen")
{
result = (input * 76.7);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Thai Baht")
{
result = (input * 31.8);
txtTo.setText(""+result);
}
else
{
result = (input * 29.7);
txtTo.setText(""+result);
}
}
public void ConvertPeso() {
if(convertTo.getSelectedItem()=="US Dollar")
{
result = (input * 0.0228);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Philippine Peso")
{
result = (input);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Japan Yen")
{
result = (input * 1.75);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Thai Baht")
{
result = (input * 0.722);
txtTo.setText(""+result);
}
else
{
result = (input * 0.681);
txtTo.setText(""+result);
}
}
public void ConvertYen() {
if(convertTo.getSelectedItem()=="US Dollar")
{
result = (input * 0.013);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Philippine Peso")
{
result = (input * 0.571);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Japan Yen")
{
result = (input);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Thai Baht")
{
result = (input * 0.414);
txtTo.setText(""+result);
}
else
{
result = (input * 0.388);
txtTo.setText(""+result);
}
}
public void ConvertBaht() {
if(convertTo.getSelectedItem()=="US Dollar")
{
result = (input * 0.0315);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Philippine Peso")
{
result = (input * 1.38);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Japan Yen")
{
result = (input * 2.42);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Thai Baht")
{
result = (input);
txtTo.setText(""+result);
}
else
{
result = (input * 0.942);
txtTo.setText(""+result);
}
}
public void ConvertTaiDollar() {
if(convertTo.getSelectedItem()=="US Dollar")
{
result = (input * 0.0336);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Philippine Peso")
{
result = (input * 1.47);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Japan Yen")
{
result = (input * 2.28);
txtTo.setText(""+result);
}
else if(convertTo.getSelectedItem()=="Thai Baht")
{
result = (input * 1.06);
txtTo.setText(""+result);
}
else
{
result = (input);
txtTo.setText(""+result);
}
}
public void actionPerformed(ActionEvent e) {
input = Double.parseDouble(txtFrom.getText());
String msg = txtFrom.getText();
if(e.getSource()==compute)
{
if(convertFrom.getSelectedItem()=="US Dollar")
{
ConvertDollar();
}
else if(convertFrom.getSelectedItem()=="Philippine Peso")
{
ConvertPeso();
}
else if(convertFrom.getSelectedItem()=="Japan Yen")
{
ConvertYen();
}
else if(convertFrom.getSelectedItem()=="Thai Baht")
{
ConvertBaht();
}
else
{
ConvertTaiDollar();
}
}
//this will asked the user to exit or not
else
{
//this will display a confirm dialog box
int choice = JOptionPane.showConfirmDialog(null,"Do you really want to quit?","Exit",JOptionPane.YES_NO_OPTION);
if(choice==0) {
dispose();
System.exit(0);
}
}
}
public void itemStateChanged(ItemEvent e)
{
}
}
Happy coding guys...
