JApplet is a simple extension of java.applet.Applet to use when creating Swing programs designed to be used in a web browser (or appletviewer ). As a direct subclass of Applet, JApplet is used in much the same way, with the init( ) , start( ), and stop( ) methods still playing critical roles. The primary thing JApplet provides that Applet does not is the use of a JRootPane as its single display component.
JApplet extends the class in the form of
java.applet.Applet. JApplets are executed in a tightly-controlled set of
resources referred to as sandboxes. This prevents the JApplets from accessing
local data like the clipboard or file system.
Ex:
import java.applet.*;
import javax.swing.*;
import java.awt.event.*;
public class EventJApplet extends JApplet implements
ActionListener{
JButton b;
JTextField tf;
public void init(){
tf=new JTextField();
tf.setBounds(30,40,150,20);
b=new JButton("Click");
b.setBounds(80,150,70,40);
add(b);add(tf);
b.addActionListener(this);
setLayout(null);
}
public void actionPerformed(ActionEvent e){
tf.setText("Welcome");
}
}
Since JApplet actually extends Applet, much of the
functionality is identical. There are a few differences, with JApplet, you have
access to the content pane, which can be called using getContentPane(). If
you have a content pane of your own (such as a panel) that you want to replace
it with, you can call setContentPane(). When you add components to your
applet, you add them to the content pane, not the frame.
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