Question

VII JAVA ASSIGNMENT.

Write a program with a graphical interface that allows the user to convert an amount of money between U.S. dollars (USD), euros (EUR), and British pounds (GBP). The user interface should have the following elements: a text box to enter the amount to be converted, two combo boxes to allow the user to select the currencies, a button to make the conversion, and a label to show the result. Display a warning if the user does not choose different currencies. Use the following conversion rates:

1 EUR is equal to 1.42 USD.

1 GBP is equal to 1.64 USD.

1 GBP is equal to 1.13 EUR.

It is the programmer’s responsibility to ensure that no matter what the user enters, the program does not crash. Call the main program Converter.java. You will need another class for the

frame.

Answer 1

`Hey,

Note: Brother in case of any queries, just comment in box I would be very happy to assist all your queries

// Converter.java

public class Converter {

                /**

                * constants for conversion rates

                */

                private static final double EUR_to_USD = 1.42;

                private static final double GBP_to_USD = 1.64;

                private static final double GBP_to_EUR = 1.13;

                /**

                * static method to convert an amount from source to target currency

                *

                * @param amount

                *            - amount to be converted

                * @param source

                *            - source unit (currency)

                * @param target

                *            - target unit

                * @return - converted value

                */

                public static double convert(double amount, Currency source, Currency target) {

                                /**

                                * performing conversions based on source and target currencies

                                */

                                if (source == Currency.USD && target == Currency.EUR) {

                                                return amount / EUR_to_USD;

                                }

                                if (source == Currency.USD && target == Currency.GBP) {

                                                return amount / GBP_to_USD;

                                }

                                if (source == Currency.EUR && target == Currency.USD) {

                                                return amount * EUR_to_USD;

                                }

                                if (source == Currency.EUR && target == Currency.GBP) {

                                                return amount / GBP_to_EUR;

                                }

                                if (source == Currency.GBP && target == Currency.USD) {

                                                return amount * GBP_to_USD;

                                }

                                if (source == Currency.GBP && target == Currency.EUR) {

                                                return amount * GBP_to_EUR;

                                }

                                return amount;// same source & target

                }

}

/**

* an enum to represent available Currency units

*/

enum Currency {

                USD, EUR, GBP

}

//end of Converter.java

// ConverterGUI.java

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JTextField;

public class ConverterGUI extends JFrame {

                /**

                * defining all required components

                */

                // an array of currencies to initialize Jcombobox

                Currency currencies[] = { Currency.USD, Currency.EUR, Currency.GBP };

                JComboBox source, target;

                JTextField input, output;

                JButton convertBtn;

                /**

                * constructor to create the GUI

                */

                public ConverterGUI() {

                                setDefaultCloseOperation(EXIT_ON_CLOSE);

                                setSize(500, 300);

                                /**

                                * using grid layout with 1 columns and any number of rows

                                */

                                setLayout(new GridLayout(0, 1));

                               

                                /**

                                * Creating and adding all UI elements in order

                                */

                               

                                add(new JLabel("Enter amount:"));

                                input = new JTextField();

                                add(input);

                                add(new JLabel("Select source currency:"));

                                source = new JComboBox(currencies);

                                add(source);

                                add(new JLabel("Select target currency:"));

                                target = new JComboBox(currencies);

                                add(target);

                                add(new JLabel("Result:"));

                                output = new JTextField();

                                output.setEditable(false);

                                add(output);

                                convertBtn = new JButton("Convert");

                                add(convertBtn);

                                setVisible(true);

                                /**

                                * adding button click listener

                                */

                                convertBtn.addActionListener(new ActionListener() {

                                                @Override

                                                public void actionPerformed(ActionEvent ae) {

                                                                try {

                                                                                /**

                                                                                * getting the amount

                                                                                */

                                                                                double amount = Double.parseDouble(input.getText());

                                                                                /**

                                                                                * getting the selected units from combo boxes

                                                                                */

                                                                                Currency sourceCurrency = (Currency) source

                                                                                                                .getSelectedItem();

                                                                                Currency targetCurrency = (Currency) target

                                                                                                                .getSelectedItem();

                                                                                /**

                                                                                * validating source and target units

                                                                                */

                                                                                if (sourceCurrency == targetCurrency) {

                                                                                                JOptionPane.showMessageDialog(null,

                                                                                                                                "Source and target currencies are same!");

                                                                                } else {

                                                                                                /**

                                                                                                * performing the conversion using static method of the Converter class

                                                                                                */

                                                                                                double result = Converter.convert(amount,

                                                                                                                                sourceCurrency, targetCurrency);

                                                                                                /**

                                                                                                * displaying the results after rounding to 2 decimal places

                                                                                                */

                                                                                                output.setText(String.format("%.2f", result));

                                                                                }

                                                                } catch (Exception e) {

                                                                                JOptionPane.showMessageDialog(null, "Invalid input amount");

                                                                }

                                                }

                                });

                }

                public static void main(String[] args) {

                                //creating the GUI

                                new ConverterGUI();

                }

}

X Enter amount: 100 Select source currency: USD Message Select target curr (i USD Source and target currencies are same! Result: ок Convert П

Enter amount: 100 Select source currency: GBP Select target currency: EUR Result 113.00 Convert X

Kindly revert for any queries

Thanks.