Adapter classes in Java - Online Help

Adapter classes in Java:

An adapter class in Java has implemented as an interface and provides an empty implementation of all methods in a particular listener interface.

The adapter classes are present in the java.awt.event package.The various java.awt.event adapter classes and the interfaces are as follow:

Adapter classes	Implements Interface
Component Adapter	Component Listener
Container Adapter	Container  Listener
Focus Adapter	Focus Listener
Key Adapter	Key Listener
Mouse Adapter	Mouse Listener
MouseMotion Adapter	MouseMotion Listener
Window Adapter	Window Listener

Sample Program Adapter classes in Java:

import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class adapterdemo extents Applet
{
public void init()
{
setBackground(Color.yellow);
addMouseListener(new Adpcls1(this));
addMouseMotionListener(new Adpcls2(this));
}
}
class Adpcls1 extents MouseAdapter
{
adapterdemo mad;
public Adpcls1(adapterdemo mad)
{
this.mad=mad;
}
public void mouseReleased(MouseEvent me)
{
mad.setBackground(Color.yellow);
mad.repaint();
}
}
class Adpcls2 extends MouseMotionAdapter
{
adapterdemo mad;
public Adpcls2(adapterdemo mad)
{
this.mad=mad;
}
public void mouseDragged(MouseEvent me)
{
mad.setBackground(Color.green);
mad.repaint();
}
}