Java program to convert Currency using AWT

Last Updated : 08 May, 2020

Swing is a part of the JFC (Java Foundation Classes). Building Graphical User Interface in Java requires the use of Swings. Swing Framework contains a large set of components which allow a high level of customization and provide rich functionalities, and is used to create window-based applications. Java swing components are lightweight, platform-independent, provide powerful components like tables, scroll panels, buttons, list, colour chooser, etc.

In this article, we’ll see how to make a currency converter which includes conversion between INR and Dollar. Two text fields are implemented with the labels Rupees and Dollar.

Note: It is assumed that 1 dollar is equal to 65.25 rupees.

Examples:

Input: INR = 130.5
Output: 2.0
Explanation:
One dollar is 65.25 rupees. So, 130.5 rupees is two dollars.

Input: Dollar = 4.5
Output: 293.625

Approach: To solve this problem, the following steps are followed:

First, we need to create a frame using JFrame.
Then, create two labels, two textfields and three buttons(the first button for rupees and the second button is for the dollar) using JLabel, JTextField and JButton.
Name these components accordingly and set their bounds.
Now, in order to perform the conversion on button click, we need to add Event Handlers. In this case, we will add ActionListener to perform an action method known as actionPerformed in which first we need to get the values from the text fields which is default as a “string”.
So, in order to perform mathematical operations, we need to convert them into double data type using Double.parseDouble(Object.getText()) and again converting from double to string to place the final value in the other text field using String.valueOf(object).
Finally, for changing the values, we use Object.setText(object), the second object is for selecting which field we want to replace.

Below is the implementation of the above approach:

// Java program to convert from 
// rupee to the dollar and vice-versa 
// using Java Swing 
  
import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 
public class GFG { 
  
    // Function to convert from rupee 
    // to the dollar and vice-versa 
    // using Java Swing 
    public static void converter() 
    { 
  
        // Creating a new frame using JFrame 
        JFrame f = new JFrame("CONVERTER"); 
  
        // Creating two labels 
        JLabel l1, l2; 
  
        // Creating two text fields. 
        // One for rupee and one for 
        // the dollar 
        JTextField t1, t2; 
  
        // Creating three buttons 
        JButton b1, b2, b3; 
  
        // Naming the labels and setting 
        // the bounds for the labels 
        l1 = new JLabel("Rupees:"); 
        l1.setBounds(20, 40, 60, 30); 
        l2 = new JLabel("Dollars:"); 
        l2.setBounds(170, 40, 60, 30); 
  
        // Initializing the text fields with 
        // 0 by default and setting the 
        // bounds for the text fields 
        t1 = new JTextField("0"); 
        t1.setBounds(80, 40, 50, 30); 
        t2 = new JTextField("0"); 
        t2.setBounds(240, 40, 50, 30); 
  
        // Creating a button for INR, 
        // one button for the dollar 
        // and one button to close 
        // and setting the bounds 
        b1 = new JButton("INR"); 
        b1.setBounds(50, 80, 60, 15); 
        b2 = new JButton("Dollar"); 
        b2.setBounds(190, 80, 60, 15); 
        b3 = new JButton("close"); 
        b3.setBounds(150, 150, 60, 30); 
  
        // Adding action listener 
        b1.addActionListener(new ActionListener() { 
            public void actionPerformed(ActionEvent e) 
            { 
                // Converting to double 
                double d 
                    = Double.parseDouble(t1.getText()); 
  
                // Converting rupees to dollars 
                double d1 = (d / 65.25); 
  
                // Getting the string value of the 
                // calculated value 
                String str1 = String.valueOf(d1); 
  
                // Placing it in the text box 
                t2.setText(str1); 
            } 
        }); 
  
        // Adding action listener 
        b2.addActionListener(new ActionListener() { 
            public void actionPerformed(ActionEvent e) 
            { 
                // Converting to double 
                double d2 
                    = Double.parseDouble(t2.getText()); 
  
                // converting Dollars to rupees 
                double d3 = (d2 * 65.25); 
  
                // Getting the string value of the 
                // calculated value 
                String str2 = String.valueOf(d3); 
  
                // Placing it in the text box 
                t1.setText(str2); 
            } 
        }); 
  
        // Action listener to close the form 
        b3.addActionListener(new ActionListener() { 
            public void actionPerformed(ActionEvent e) 
            { 
                f.dispose(); 
            } 
        }); 
  
        // Default method for closing the frame 
        f.addWindowListener(new WindowAdapter() { 
            public void windowClosing(WindowEvent e) 
            { 
                System.exit(0); 
            } 
        }); 
  
        // Adding the created objects 
        // to the form 
        f.add(l1); 
        f.add(t1); 
        f.add(l2); 
        f.add(t2); 
        f.add(b1); 
        f.add(b2); 
        f.add(b3); 
  
        f.setLayout(null); 
        f.setSize(400, 300); 
        f.setVisible(true); 
    } 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        converter(); 
    } 
} 