What is JApplet in Swing?

Exploring Java's JApplet in Swing for Interactive and Dynamic GUI Applications

  • JApplet:

    • JApplet is a class in javax.swing that represents swing applet.

    • An applet is a small program which runs in the web browser.

    • To create a Swing applet developers often extend the JApplet class.

Life Cycle methods:

There are 4 methods to represent the life cycle of the JApplet and they are:

  1. intit(): it is called only once when the applet is created.

  2. start(): it is called whenever the applet becomes not visible or starts after being paused.

  3. stop(): it is called whenever the applet becomes not visible or when the applet is paused.

  4. destroy(): it is called when the applet is about to be unloaded.

Swing components in applets:

  • Like JFrame, JApplet can include various Swing components like buttons, labels and panels.

  • To add swing components to JApplet we can follow the same principles which we followed to use JFrame.

Displaying in a web browser:

  • To display JApplet in a web browser we can use <applet> tag embedded with the .class file in HTML

Layout managers:

Layout managers like flow layout, border layout and others can be used to arrange components within the applet.

Event Handling:

Event handling in swing applets is done using Listeners to capture user interactions.

Program:

  •   // Java program to demonstrate using JApplet.
    
      import javax.swing.JApplet;
      import javax.swing.JButton;
      import java.awt.event.ActionEvent;
      import java.awt.event.ActionListener;
    
      class MyApplet extends JApplet {
          public void init() {
          JButton button = new JButton("Click me");
          button.addActionListener(new ActionListener()
          {
              public void actionPerformed(ActionEvent e) {
                  System.out.println("Button Clicked");
              }
          });
          add(button);
          }
          public void start(){}
          public void stop(){}
          public void destroy(){}
      }