·
Swing-based
Applets are similar to AWT-based Applets, but with an important difference: A
Swing applet extends JApplet rather
than Applet. JApplet is derived from Applet.
Thus it includes all of the functionality found in Applet and add support for
Swing. JApplet is a top-level Swing container, which means that it is not
derived from JComponent.
·
Swing Applets
uses the four lifecycle methods: init(),
start(), stop(), and destroy().
We have to override only those methods that are needed by our applet.
·
Painting is
accomplished differently in Swing than it is in the AWT, and a Swing Applet
will not normally override the paint()
method.
·
All interactions
with components in a Swing Applet must take place on the event dispatching
thread.
·
Example:
AppletSwing.java
import
java.awt.*;
import
java.awt.event.*;
import
javax.swing.*;
public
class AppletSwing extends JApplet
{
JButton b1;
JLabel jbl;
public void init()
{
try {
SwingUtilities.invokeAndWait(new
Runnable(){
public void run()
{
makeGUI();
}
});
}catch(Exception e)
{
System.out.println("Error Occured
"+e);
}
}
private void makeGUI()
{
setLayout(new FlowLayout());
b1=new JButton("Button1");
b1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
jbl.setText("Button 1 is
pressed");
}
});
add(b1);
jbl=new
JLabel("Press a button");
add(jbl);
}
}
SwingApplet.html
<html>
<head>
<body>
<applet
code="AppletSwing.class"
width=200
height=200 >
</applet>
</body>
</html>
·
Swing Applets
must use invokeAndWait() rather than
invokeLater() because the init() method must not return until the
entire initialization process has been completed.
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