Design and create GUI applications
Write a Java applet to add two numbers from text fields, and displays the result in a non-editable text field. Enable your applet to run standalone with a main method. A sample run of the applet is shown in the following figure.

Question

Design and create GUI applications 
Write a Java applet to add two numbers from text fields, and displays the result in a non-editable text field. Enable your applet to run standalone with a main method. A sample run of the applet is shown in the following figure.

Quizplus · Accepted Answer

The Answer is import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Test extends JApplet {
// Text fields for Number 1, Number 2, and Result
private JTextField jtfNum1, jtfNum2, jtfResult;
// Buttons "Add"
private JButton jbtAdd;
// Main method
public static void main(String[] args) {
// Create a frame
JFrame frame = new JFrame("Test");
// Create an instance of the applet
Test applet = new Test();
// Add the applet instance to the frame
frame.add(applet, BorderLayout.CENTER);
// Invoke init() and start()
applet.init();
applet.start();
// Display the frame
frame.pack();
frame.setLocationRelativeTo(null); // Center the frame
frame.setVisible(true);
}
// Default Constructor
public Test() {
// Panel p1 to hold text fields and labels
JPanel p1 = new JPanel();
p1.setLayout(new FlowLayout());
p1.add(new JLabel("Number 1"));
p1.add(jtfNum1 = new JTextField(3));
p1.add(new JLabel("Number 2"));
p1.add(jtfNum2 = new JTextField(3));
p1.add(new JLabel("Result"));
p1.add(jtfResult = new JTextField(8));
jtfResult.setEditable(false);
jtfResult.setHorizontalAlignment(SwingConstants.RIGHT);
// Panel p2 to hold buttons
JPanel p2 = new JPanel();
p2.setLayout(new FlowLayout());
p2.add(jbtAdd = new JButton("Add"));
// Set mnemonic keys
jbtAdd.setMnemonic('A');
// Add panels to the frame
setLayout(new BorderLayout());
add(p1, BorderLayout.CENTER);
add(p2, BorderLayout.SOUTH);
// Register listeners
jbtAdd.addActionListener(new Listener());
}
class Listener implements ActionListener {
// Handle ActionEvent from buttons
public void actionPerformed(ActionEvent e) {
// Obtain Number 1 and Number 2
int num1 = Integer.parseInt(jtfNum1.getText().trim());
int num2 = Integer.parseInt(jtfNum2.getText().trim());
int result = num1 + num2;
// Set result in jtfResult
jtfResult.setText(String.valueOf(result));
}
}
}

Design and Create GUI Applications