Program using SApplet
Implementation of the SApplet program is mentioned below:
Java
// Java Program for Using Swing Applet in Java import java.awt.*; import java.awt.event.*; import javax.swing.*; // Defining a class named SApplet that extends JApplet and // implements the ActionListener interface public class SApplet extends JApplet implements ActionListener { JTextField num1, num2, res; JButton resBtn; // This is Initialization method for the applet public void init() { // Creating three text fields for number input and // one button for calculation result num1 = new JTextField(5); num2 = new JTextField(5); res = new JTextField(10); // Make the result field non-editable res.setEditable(false); resBtn = new JButton("Multiply"); // Register this applet as the action // listener for the button resBtn.addActionListener(this); // Creating labels for the input fields and result JLabel l1 = new JLabel("Enter Number 1:"); JLabel l2 = new JLabel("Enter Number 2:"); JLabel l3 = new JLabel("Result:"); l1.setForeground(Color.black); l2.setForeground(Color.black); l3.setForeground(Color.black); // Creating a JPanel to arrange // components in a grid layout JPanel pan = new JPanel(); pan.setLayout(new GridLayout(4, 2)); // Adding labels, input fields, button, and empty // label for spacing pan.add(l1); pan.add(num1); pan.add(l2); pan.add(num2); // Set button background color resBtn.setBackground(Color.orange); pan.add(resBtn); // Empty label for spacing pan.add(new JLabel()); pan.add(l3); pan.add(res); // Set text color Customize the fonts of various // components pan.setForeground(Color.black); Font lfont = l1.getFont(); // Creating a new font with size 20 Font inFont = lfont.deriveFont(Font.PLAIN, 20); l1.setFont(inFont); l2.setFont(inFont); l3.setFont(inFont); num1.setFont(inFont); num2.setFont(inFont); res.setFont(inFont); resBtn.setFont(inFont); // Set the layout of the applet to BorderLayout and // add the JPanel to the center setLayout(new BorderLayout()); add(pan, BorderLayout.CENTER); } // ActionListener method to handle button clicks public void actionPerformed(ActionEvent e){ // Check if the event source is the Multiply button if (e.getSource() == resBtn) { String str1 = num1.getText(); String str2 = num2.getText(); try { int num1 = Integer.parseInt(str1); int num2 = Integer.parseInt(str2); int result = num1 * num2; // Display the result in result text field res.setText(Integer.toString(result)); } catch (NumberFormatException ex) { // Display an error message for invalid input res.setText("Wrong Input"); } } } } |
Output for the Program:
Explanation of the Program
- We have imported the packages which are required to create the GUI interface of the application.
- Then we have defined the class called as ‘SApplet’ which mainly enters the ‘JApplet’ and implements the ‘ActionListener’ interface.
- There are instance variables like num1 and num2 for text fields, resBtn is the button to perform the multiplication.
- There is an init method which is called when the application is been initialized. We are creating the text fields, lbales, JPanel using this method.
- For customization purposes, we have used the Font sizes and colors applied on labels and input fields. Also, we have designed the JPanel pan, to manage the components properly in the grid manner.
- Then there is the actionPerformed() method, which mainly is called when the action on the button is been done. Here the text from the text fields num1 and num2 is been returned and the result is been displayed in the res text field of multiplication.
How to Use Swing Applet in Java?
In this article, we will be using the swing Applet or JApplet in Java. Here, we will make a simple multiplication application that will multiply the two input numbers.