Java AWT Tutorial

Java AWT (Abstract Window Toolkit) is an API to develop GUI or window-based applications in java.

Java AWT components are platform-dependent i.e. components are displayed according to the view of operating system. AWT is heavyweight i.e. its components are using the resources of OS.

The java.awt package provides classes for AWT api such as TextField, Label, TextArea, RadioButton, CheckBox, Choice, List etc.

Container

The Container is a component in AWT that can contain another components like buttons, textfields, labels etc. The classes that extends Container class are known as container such as Frame, Dialog and Panel.

Window

The window is the container that have no borders and menu bars. You must use frame, dialog or another window for creating a window.

Panel

The Panel is the container that doesn't contain title bar and menu bars. It can have other components like button, textfield etc.

Frame

The Frame is the container that contain title bar and can have menu bars. It can have other components like button, textfield etc.

Useful Methods of Component class

Method	Description
public void add(Component c)	inserts a component on this component.
public void setSize(int width,int height)	sets the size (width and height) of the component.
public void setLayout(LayoutManager m)	defines the layout manager for the component.
public void setVisible(boolean status)	changes the visibility of the component, by default false.

Java AWT Example

To create simple awt example, you need a frame. There are two ways to create a frame in AWT.

By extending Frame class (inheritance)
By creating the object of Frame class (association)

AWT Example by Inheritance

import java.awt.*;

class First extends Frame{

First(){

Button b=new Button("click me");

b.setBounds(30,100,80,30);// setting button position

add(b);//adding button into frame

setSize(300,300);//frame size 300 width and 300 height

setLayout(null);//no layout now bydefault BorderLayout

setVisible(true);//now frame willbe visible, bydefault not visible

}

public static void main(String args[]){

First f=new First();

}

AWT Example by Association

import java.awt.*;

class First2{

First2(){

Frame f=new Frame();

Button b=new Button("click me");

b.setBounds(30,50,80,30);

f.add(b);

f.setSize(300,300);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[]){

First2 f=new First2();

}}

Event and Listener (Java Event Handling)

Changing the state of an object is known as an event. For example, click on button, dragging mouse etc. The java.awt.event package provides many event classes and Listener interfaces for event handling.

Java Event classes and Listener interfaces

Event Classes	Listener Interfaces
ActionEvent	ActionListener
MouseEvent	MouseListener and MouseMotionListener
MouseWheelEvent	MouseWheelListener
KeyEvent	KeyListener
ItemEvent	ItemListener
TextEvent	TextListener
AdjustmentEvent	AdjustmentListener
WindowEvent	WindowListener
ComponentEvent	ComponentListener
ContainerEvent	ContainerListener
FocusEvent	FocusListener

Registration Methods

For registering the component with the Listener, many classes provide the registration methods. For example:

Button

public void addActionListener(ActionListener a){}

MenuItem

public void addActionListener(ActionListener a){}

TextField

public void addActionListener(ActionListener a){}
public void addTextListener(TextListener a){}

TextArea

public void addTextListener(TextListener a){}

Checkbox

public void addItemListener(ItemListener a){}

Choice

public void addItemListener(ItemListener a){}

List

public void addActionListener(ActionListener a){}
public void addItemListener(ItemListener a){}

Java event handling by implementing ActionListener

import java.awt.*;

import java.awt.event.*;

class AEvent extends Frame implements ActionListener{

TextField tf;

AEvent(){

//create components

tf=new TextField();

tf.setBounds(60,50,170,20);

Button b=new Button("click me");

b.setBounds(100,120,80,30);

//register listener

b.addActionListener(this);//passing current instance

//add components and set size, layout and visibility

add(b);add(tf);

setSize(300,300);

setLayout(null);

setVisible(true);

}

public void actionPerformed(ActionEvent e){

tf.setText("Welcome");

}

public static void main(String args[]){

new AEvent();

}

Java AWT Button

The button class is used to create a labeled button that has platform independent implementation. The application result in some action when the button is pushed.

AWT Button Class declaration

public class Button extends Component implements Accessible

Java AWT Button Example

import java.awt.*;

public class ButtonExample {

public static void main(String[] args) {

Frame f=new Frame("Button Example");

Button b=new Button("Click Here");

b.setBounds(50,100,80,30);

f.add(b);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

Java AWT Button Example with ActionListener

import java.awt.*;

import java.awt.event.*;

public class ButtonExample {

public static void main(String[] args) {

Frame f=new Frame("Button Example");

final TextField tf=new TextField();

tf.setBounds(50,50, 150,20);

Button b=new Button("Click Here");

b.setBounds(50,100,60,30);

b.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e){

tf.setText("Welcome");

}

});

f.add(b);f.add(tf);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

Java AWT Label

The object of Label class is a component for placing text in a container. It is used to display a single line of read only text. The text can be changed by an application but a user cannot edit it directly.

AWT Label Class Declaration

public class Label extends Component implements Accessible

Java Label Example

import java.awt.*;

class LabelExample{

public static void main(String args[]){

Frame f= new Frame("Label Example");

Label l1,l2;

l1=new Label("First Label.");

l1.setBounds(50,100, 100,30);

l2=new Label("Second Label.");

l2.setBounds(50,150, 100,30);

f.add(l1); f.add(l2);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

Java AWT Label Example with ActionListener

import java.awt.*;

import java.awt.event.*;

public class LabelExample extends Frame implements ActionListener{

TextField tf; Label l; Button b;

LabelExample(){

tf=new TextField();

tf.setBounds(50,50, 150,20);

l=new Label();

l.setBounds(50,100, 250,20);

b=new Button("Find IP");

b.setBounds(50,150,60,30);

b.addActionListener(this);

add(b);add(tf);add(l);

setSize(400,400);

setLayout(null);

setVisible(true);

}

public void actionPerformed(ActionEvent e) {

try{

String host=tf.getText();

String ip=java.net.InetAddress.getByName(host).getHostAddress();

l.setText("IP of "+host+" is: "+ip);

}catch(Exception ex){

System.out.println(ex);

}

public static void main(String[] args) {

new LabelExample();

}

Java AWT TextField

The object of a TextField class is a text component that allows the editing of a single line text. It inherits TextComponent class.

AWT TextField Class Declaration

public class TextField extends TextComponent

Java AWT TextField Example

import java.awt.*;

class TextFieldExample{

public static void main(String args[]){

Frame f= new Frame("TextField Example");

TextField t1,t2;

t1=new TextField("Welcome to Javatpoint.");

t1.setBounds(50,100, 200,30);

t2=new TextField("AWT Tutorial");

t2.setBounds(50,150, 200,30);

f.add(t1); f.add(t2);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

Java AWT TextField Example with ActionListener

import java.awt.*;

import java.awt.event.*;

public class TextFieldExample extends Frame implements ActionListener{

TextField tf1,tf2,tf3;

Button b1,b2;

TextFieldExample(){

tf1=new TextField();

tf1.setBounds(50,50,150,20);

tf2=new TextField();

tf2.setBounds(50,100,150,20);

tf3=new TextField();

tf3.setBounds(50,150,150,20);

tf3.setEditable(false);

b1=new Button("+");

b1.setBounds(50,200,50,50);

b2=new Button("-");

b2.setBounds(120,200,50,50);

b1.addActionListener(this);

b2.addActionListener(this);

add(tf1);add(tf2);add(tf3);add(b1);add(b2);

setSize(300,300);

setLayout(null);

setVisible(true);

}

public void actionPerformed(ActionEvent e) {

String s1=tf1.getText();

String s2=tf2.getText();

int a=Integer.parseInt(s1);

int b=Integer.parseInt(s2);

int c=0;

if(e.getSource()==b1){

c=a+b;

}else if(e.getSource()==b2){

c=a-b;

}

String result=String.valueOf(c);

tf3.setText(result);

}

public static void main(String[] args) {

new TextFieldExample();

}

Java AWT Checkbox

The Checkbox class is used to create a checkbox. It is used to turn an option on (true) or off (false). Clicking on a Checkbox changes its state from "on" to "off" or from "off" to "on".

AWT Checkbox Class Declaration

public class Checkbox extends Component implements ItemSelectable, Accessible

Java AWT Checkbox Example

import java.awt.*;

public class CheckboxExample

{

CheckboxExample(){

Frame f= new Frame("Checkbox Example");

Checkbox checkbox1 = new Checkbox("C++");

checkbox1.setBounds(100,100, 50,50);

Checkbox checkbox2 = new Checkbox("Java", true);

checkbox2.setBounds(100,150, 50,50);

f.add(checkbox1);

f.add(checkbox2);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new CheckboxExample();

}

Java AWT Checkbox Example with ItemListener

import java.awt.*;

import java.awt.event.*;

public class CheckboxExample

{

CheckboxExample(){

Frame f= new Frame("CheckBox Example");

final Label label = new Label();

label.setAlignment(Label.CENTER);

label.setSize(400,100);

Checkbox checkbox1 = new Checkbox("C++");

checkbox1.setBounds(100,100, 50,50);

Checkbox checkbox2 = new Checkbox("Java");

checkbox2.setBounds(100,150, 50,50);

f.add(checkbox1); f.add(checkbox2); f.add(label);

checkbox1.addItemListener(new ItemListener() {

public void itemStateChanged(ItemEvent e) {

label.setText("C++ Checkbox: "

+ (e.getStateChange()==1?"checked":"unchecked"));

}

});

checkbox2.addItemListener(new ItemListener() {

public void itemStateChanged(ItemEvent e) {

label.setText("Java Checkbox: "

+ (e.getStateChange()==1?"checked":"unchecked"));

}

});

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new CheckboxExample();

}

Java AWT CheckboxGroup

The object of CheckboxGroup class is used to group together a set of Checkbox. At a time only one check box button is allowed to be in "on" state and remaining check box button in "off" state. It inherits the object class.

Note: CheckboxGroup enables you to create radio buttons in AWT. There is no special control for creating radio buttons in AWT.

AWT CheckboxGroup Class Declaration

public class CheckboxGroup extends Object implements Serializable

Java AWT CheckboxGroup Example

import java.awt.*;

public class CheckboxGroupExample

{

CheckboxGroupExample(){

Frame f= new Frame("CheckboxGroup Example");

CheckboxGroup cbg = new CheckboxGroup();

Checkbox checkBox1 = new Checkbox("C++", cbg, false);

checkBox1.setBounds(100,100, 50,50);

Checkbox checkBox2 = new Checkbox("Java", cbg, true);

checkBox2.setBounds(100,150, 50,50);

f.add(checkBox1);

f.add(checkBox2);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new CheckboxGroupExample();

}

Java AWT CheckboxGroup Example with ItemListener

import java.awt.*;

import java.awt.event.*;

public class CheckboxGroupExample

{

CheckboxGroupExample(){

Frame f= new Frame("CheckboxGroup Example");

final Label label = new Label();

label.setAlignment(Label.CENTER);

label.setSize(400,100);

CheckboxGroup cbg = new CheckboxGroup();

Checkbox checkBox1 = new Checkbox("C++", cbg, false);

checkBox1.setBounds(100,100, 50,50);

Checkbox checkBox2 = new Checkbox("Java", cbg, false);

checkBox2.setBounds(100,150, 50,50);

f.add(checkBox1); f.add(checkBox2); f.add(label);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

checkBox1.addItemListener(new ItemListener() {

public void itemStateChanged(ItemEvent e) {

label.setText("C++ checkbox: Checked");

}

});

checkBox2.addItemListener(new ItemListener() {

public void itemStateChanged(ItemEvent e) {

label.setText("Java checkbox: Checked");

}

});

}

public static void main(String args[])

{

new CheckboxGroupExample();

}

Java AWT Choice

The object of Choice class is used to show popup menu of choices. Choice selected by user is shown on the top of a menu. It inherits Component class.

AWT Choice Class Declaration

public class Choice extends Component implements ItemSelectable, Accessible

Java AWT Choice Example

import java.awt.*;

public class ChoiceExample

{

ChoiceExample(){

Frame f= new Frame();

Choice c=new Choice();

c.setBounds(100,100, 75,75);

c.add("Item 1");

c.add("Item 2");

c.add("Item 3");

c.add("Item 4");

c.add("Item 5");

f.add(c);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new ChoiceExample();

}

Java AWT Choice Example with ActionListener

import java.awt.*;

import java.awt.event.*;

public class ChoiceExample

{

ChoiceExample(){

Frame f= new Frame();

final Label label = new Label();

label.setAlignment(Label.CENTER);

label.setSize(400,100);

Button b=new Button("Show");

b.setBounds(200,100,50,20);

final Choice c=new Choice();

c.setBounds(100,100, 75,75);

c.add("C");

c.add("C++");

c.add("Java");

c.add("PHP");

c.add("Android");

f.add(c);f.add(label); f.add(b);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

b.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

String data = "Programming language Selected: "+ c.getItem(c.getSelectedIndex());

label.setText(data);

}

});

}

public static void main(String args[])

{

new ChoiceExample();

}

Java AWT List

The object of List class represents a list of text items. By the help of list, user can choose either one item or multiple items. It inherits Component class.

AWT List class Declaration

public class List extends Component implements ItemSelectable, Accessible

Java AWT List Example

import java.awt.*;

public class ListExample

{

ListExample(){

Frame f= new Frame();

List l1=new List(5);

l1.setBounds(100,100, 75,75);

l1.add("Item 1");

l1.add("Item 2");

l1.add("Item 3");

l1.add("Item 4");

l1.add("Item 5");

f.add(l1);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new ListExample();

}

Java AWT List Example with ActionListener

import java.awt.*;

import java.awt.event.*;

public class ListExample

{

ListExample(){

Frame f= new Frame();

final Label label = new Label();

label.setAlignment(Label.CENTER);

label.setSize(500,100);

Button b=new Button("Show");

b.setBounds(200,150,80,30);

final List l1=new List(4, false);

l1.setBounds(100,100, 70,70);

l1.add("C");

l1.add("C++");

l1.add("Java");

l1.add("PHP");

final List l2=new List(4, true);

l2.setBounds(100,200, 70,70);

l2.add("Turbo C++");

l2.add("Spring");

l2.add("Hibernate");

l2.add("CodeIgniter");

f.add(l1); f.add(l2); f.add(label); f.add(b);

f.setSize(450,450);

f.setLayout(null);

f.setVisible(true);

b.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

String data = "Programming language Selected: "+l1.getItem(l1.getSelectedIndex());

data += ", Framework Selected:";

for(String frame:l2.getSelectedItems()){

data += frame + " ";

}

label.setText(data);

}

});

}

public static void main(String args[])

{

new ListExample();

}

Java AWT Canvas

The Canvas control represents a blank rectangular area where the application can draw or trap input events from the user. It inherits the Component class.

AWT Canvas class Declaration

public class Canvas extends Component implements Accessible

Java AWT Canvas Example

import java.awt.*;

public class CanvasExample

{

public CanvasExample()

{

Frame f= new Frame("Canvas Example");

f.add(new MyCanvas());

f.setLayout(null);

f.setSize(400, 400);

f.setVisible(true);

}

public static void main(String args[])

{

new CanvasExample();

}

class MyCanvas extends Canvas

{

public MyCanvas() {

setBackground (Color.GRAY);

setSize(300, 200);

}

public void paint(Graphics g)

{

g.setColor(Color.red);

g.fillOval(75, 75, 150, 75);

}

Java AWT Scrollbar

The object of Scrollbar class is used to add horizontal and vertical scrollbar. Scrollbar is a GUI component allows us to see invisible number of rows and columns.

AWT Scrollbar class declaration

public class Scrollbar extends Component implements Adjustable, Accessible

Java AWT Scrollbar Example

import java.awt.*;

class ScrollbarExample{

ScrollbarExample(){

Frame f= new Frame("Scrollbar Example");

Scrollbar s=new Scrollbar();

s.setBounds(100,100, 50,100);

f.add(s);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[]){

new ScrollbarExample();

}

Java AWT Scrollbar Example with AdjustmentListener

import java.awt.*;

import java.awt.event.*;

public class ScrollbarExample{

ScrollbarExample(){

Frame f= new Frame("Scrollbar Example");

final Label label = new Label();

label.setAlignment(Label.CENTER);

label.setSize(400,100);

final Scrollbar s=new Scrollbar();

s.setBounds(100,100, 50,100);

f.add(s);f.add(label);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

s.addAdjustmentListener(new AdjustmentListener() {

public void adjustmentValueChanged(AdjustmentEvent e) {

label.setText("Vertical Scrollbar value is:"+ s.getValue());

}

});

}

public static void main(String args[]){

new ScrollbarExample();

}

Java AWT MenuItem and Menu

The object of MenuItem class adds a simple labeled menu item on menu. The items used in a menu must belong to the MenuItem or any of its subclass.

The object of Menu class is a pull down menu component which is displayed on the menu bar. It inherits the MenuItem class.

AWT MenuItem class declaration

public class MenuItem extends MenuComponent implements Accessible

AWT Menu class declaration

public class Menu extends MenuItem implements MenuContainer, Accessible

Java AWT MenuItem and Menu Example

import java.awt.*;

class MenuExample

{

MenuExample(){

Frame f= new Frame("Menu and MenuItem Example");

MenuBar mb=new MenuBar();

Menu menu=new Menu("Menu");

Menu submenu=new Menu("Sub Menu");

MenuItem i1=new MenuItem("Item 1");

MenuItem i2=new MenuItem("Item 2");

MenuItem i3=new MenuItem("Item 3");

MenuItem i4=new MenuItem("Item 4");

MenuItem i5=new MenuItem("Item 5");

menu.add(i1);

menu.add(i2);

menu.add(i3);

submenu.add(i4);

submenu.add(i5);

menu.add(submenu);

mb.add(menu);

f.setMenuBar(mb);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new MenuExample();

}

Java AWT PopupMenu

PopupMenu can be dynamically popped up at specific position within a component. It inherits the Menu class.

AWT PopupMenu class declaration

public class PopupMenu extends Menu implements MenuContainer, Accessible

Java AWT PopupMenu Example

import java.awt.*;

import java.awt.event.*;

class PopupMenuExample

{

PopupMenuExample(){

final Frame f= new Frame("PopupMenu Example");

final PopupMenu popupmenu = new PopupMenu("Edit");

MenuItem cut = new MenuItem("Cut");

cut.setActionCommand("Cut");

MenuItem copy = new MenuItem("Copy");

copy.setActionCommand("Copy");

MenuItem paste = new MenuItem("Paste");

paste.setActionCommand("Paste");

popupmenu.add(cut);

popupmenu.add(copy);

popupmenu.add(paste);

f.addMouseListener(new MouseAdapter() {

public void mouseClicked(MouseEvent e) {

popupmenu.show(f , e.getX(), e.getY());

}

});

f.add(popupmenu);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new PopupMenuExample();

}

Java AWT Panel

The Panel is a simplest container class. It provides space in which an application can attach any other component. It inherits the Container class.

It doesn't have title bar.

AWT Panel class declaration

public class Panel extends Container implements Accessible

Java AWT Panel Example

import java.awt.*;

public class PanelExample {

PanelExample()

{

Frame f= new Frame("Panel Example");

Panel panel=new Panel();

panel.setBounds(40,80,200,200);

panel.setBackground(Color.gray);

Button b1=new Button("Button 1");

b1.setBounds(50,100,80,30);

b1.setBackground(Color.yellow);

Button b2=new Button("Button 2");

b2.setBounds(100,100,80,30);

b2.setBackground(Color.green);

panel.add(b1); panel.add(b2);

f.add(panel);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String args[])

{

new PanelExample();

}

java awt Panel example 1

Java AWT Dialog

The Dialog control represents a top level window with a border and a title used to take some form of input from the user. It inherits the Window class.

Unlike Frame, it doesn't have maximize and minimize buttons.

Frame vs Dialog

Frame and Dialog both inherits Window class. Frame has maximize and minimize buttons but Dialog doesn't have.

AWT Dialog class declaration

public class Dialog extends Window

Java AWT Dialog Example

import java.awt.*;

import java.awt.event.*;

public class DialogExample {

private static Dialog d;

DialogExample() {

Frame f= new Frame();

d = new Dialog(f , "Dialog Example", true);

d.setLayout( new FlowLayout() );

Button b = new Button ("OK");

b.addActionListener ( new ActionListener()

{

public void actionPerformed( ActionEvent e )

{

DialogExample.d.setVisible(false);

}

});

d.add( new Label ("Click button to continue."));

d.add(b);

d.setSize(300,300);

d.setVisible(true);

}

public static void main(String args[])

{

new DialogExample();

}

Java AWT Toolkit

Toolkit class is the abstract superclass of every implementation in the Abstract Window Toolkit. Subclasses of Toolkit are used to bind various components. It inherits Object class.

AWT Toolkit class declaration

public abstract class Toolkit extends Object

Java AWT Toolkit Example

import java.awt.*;

public class ToolkitExample {

public static void main(String[] args) {

Toolkit t = Toolkit.getDefaultToolkit();

System.out.println("Screen resolution = " + t.getScreenResolution());

Dimension d = t.getScreenSize();

System.out.println("Screen width = " + d.width);

System.out.println("Screen height = " + d.height);

}

Java AWT Toolkit Example: beep()

import java.awt.*;

import java.awt.event.*;

public class ToolkitExample2 {

public static void main(String[] args) {

Frame f=new Frame("ToolkitExample");

Button b=new Button("beep");

b.setBounds(50,100,60,30);

f.add(b);

f.setSize(300,300);

f.setLayout(null);

f.setVisible(true);

b.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e){

Toolkit.getDefaultToolkit().beep();

}

});

}

Java ActionListener Interface

The Java ActionListener is notified whenever you click on the button or menu item. It is notified against ActionEvent. The ActionListener interface is found in java.awt.event package. It has only one method: actionPerformed().

actionPerformed() method

The actionPerformed() method is invoked automatically whenever you click on the registered component.

public abstract void actionPerformed(ActionEvent e);

Java ActionListener Example: On Button click

import java.awt.*;

import java.awt.event.*;

public class ActionListenerExample {

public static void main(String[] args) {

Frame f=new Frame("ActionListener Example");

final TextField tf=new TextField();

tf.setBounds(50,50, 150,20);

Button b=new Button("Click Here");

b.setBounds(50,100,60,30);

b.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e){

tf.setText("Welcome to Javatpoint.");

}

});

f.add(b);f.add(tf);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

Java MouseListener Interface

The Java MouseListener is notified whenever you change the state of mouse. It is notified against MouseEvent. The MouseListener interface is found in java.awt.event package. It has five methods.

Methods of MouseListener interface

The signature of 5 methods found in MouseListener interface are given below:

public abstract void mouseClicked(MouseEvent e);
public abstract void mouseEntered(MouseEvent e);
public abstract void mouseExited(MouseEvent e);
public abstract void mousePressed(MouseEvent e);
public abstract void mouseReleased(MouseEvent e);

Java MouseListener Example

import java.awt.*;

import java.awt.event.*;

public class MouseListenerExample extends Frame implements MouseListener{

Label l;

MouseListenerExample(){

addMouseListener(this);

l=new Label();

l.setBounds(20,50,100,20);

add(l);

setSize(300,300);

setLayout(null);

setVisible(true);

}

public void mouseClicked(MouseEvent e) {

l.setText("Mouse Clicked");

}

public void mouseEntered(MouseEvent e) {

l.setText("Mouse Entered");

}

public void mouseExited(MouseEvent e) {

l.setText("Mouse Exited");

}

public void mousePressed(MouseEvent e) {

l.setText("Mouse Pressed");

}

public void mouseReleased(MouseEvent e) {

l.setText("Mouse Released");

}

public static void main(String[] args) {

new MouseListenerExample();

}

Java MouseMotionListener Interface

The Java MouseMotionListener is notified whenever you move or drag mouse. It is notified against MouseEvent. The MouseMotionListener interface is found in java.awt.event package. It has two methods.

Methods of MouseMotionListener interface

The signature of 2 methods found in MouseMotionListener interface are given below:

public abstract void mouseDragged(MouseEvent e);
public abstract void mouseMoved(MouseEvent e);

Java MouseMotionListener Example

import java.awt.*;

import java.awt.event.*;

public class MouseMotionListenerExample extends Frame implements MouseMotionListener{

MouseMotionListenerExample(){

addMouseMotionListener(this);

setSize(300,300);

setLayout(null);

setVisible(true);

}

public void mouseDragged(MouseEvent e) {

Graphics g=getGraphics();

g.setColor(Color.BLUE);

g.fillOval(e.getX(),e.getY(),20,20);

}

public void mouseMoved(MouseEvent e) {}

public static void main(String[] args) {

new MouseMotionListenerExample();

}

Java ItemListener Interface

The Java ItemListener is notified whenever you click on the checkbox. It is notified against ItemEvent. The ItemListener interface is found in java.awt.event package. It has only one method: itemStateChanged().

itemStateChanged() method

The itemStateChanged() method is invoked automatically whenever you click or unclick on the registered checkbox component.

public abstract void itemStateChanged(ItemEvent e);

Java ItemListener Example

import java.awt.*;

import java.awt.event.*;

public class ItemListenerExample implements ItemListener{

Checkbox checkBox1,checkBox2;

Label label;

ItemListenerExample(){

Frame f= new Frame("CheckBox Example");

label = new Label();

label.setAlignment(Label.CENTER);

label.setSize(400,100);

checkBox1 = new Checkbox("C++");

checkBox1.setBounds(100,100, 50,50);

checkBox2 = new Checkbox("Java");

checkBox2.setBounds(100,150, 50,50);

f.add(checkBox1); f.add(checkBox2); f.add(label);

checkBox1.addItemListener(this);

checkBox2.addItemListener(this);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public void itemStateChanged(ItemEvent e) {

if(e.getSource()==checkBox1)

label.setText("C++ Checkbox: "

+ (e.getStateChange()==1?"checked":"unchecked"));

if(e.getSource()==checkBox2)

label.setText("Java Checkbox: "

+ (e.getStateChange()==1?"checked":"unchecked"));

}

public static void main(String args[])

{

new ItemListenerExample();

}

Java KeyListener Interface

The Java KeyListener is notified whenever you change the state of key. It is notified against KeyEvent. The KeyListener interface is found in java.awt.event package. It has three methods.

Methods of KeyListener interface

The signature of 3 methods found in KeyListener interface are given below:

public abstract void keyPressed(KeyEvent e);
public abstract void keyReleased(KeyEvent e);
public abstract void keyTyped(KeyEvent e);

Java KeyListener Example

import java.awt.*;

import java.awt.event.*;

public class KeyListenerExample extends Frame implements KeyListener{

Label l;

TextArea area;

KeyListenerExample(){

l=new Label();

l.setBounds(20,50,100,20);

area=new TextArea();

area.setBounds(20,80,300, 300);

area.addKeyListener(this);

add(l);add(area);

setSize(400,400);

setLayout(null);

setVisible(true);

}

public void keyPressed(KeyEvent e) {

l.setText("Key Pressed");

}

public void keyReleased(KeyEvent e) {

l.setText("Key Released");

}

public void keyTyped(KeyEvent e) {

l.setText("Key Typed");

}

public static void main(String[] args) {

new KeyListenerExample();

}

Java WindowListener Interface

The Java WindowListener is notified whenever you change the state of window. It is notified against WindowEvent. The WindowListener interface is found in java.awt.event package. It has three methods.

Methods of WindowListener interface

The signature of 7 methods found in WindowListener interface are given below:

public abstract void windowActivated(WindowEvent e);
public abstract void windowClosed(WindowEvent e);
public abstract void windowClosing(WindowEvent e);
public abstract void windowDeactivated(WindowEvent e);
public abstract void windowDeiconified(WindowEvent e);
public abstract void windowIconified(WindowEvent e);
public abstract void windowOpened(WindowEvent e);

Java WindowListener Example

import java.awt.*;

import java.awt.event.WindowEvent;

import java.awt.event.WindowListener;

public class WindowExample extends Frame implements WindowListener{

WindowExample(){

addWindowListener(this);

setSize(400,400);

setLayout(null);

setVisible(true);

}

public static void main(String[] args) {

new WindowExample();

}

public void windowActivated(WindowEvent arg0) {

System.out.println("activated");

}

public void windowClosed(WindowEvent arg0) {

System.out.println("closed");

}

public void windowClosing(WindowEvent arg0) {

System.out.println("closing");

dispose();

}

public void windowDeactivated(WindowEvent arg0) {

System.out.println("deactivated");

}

public void windowDeiconified(WindowEvent arg0) {

System.out.println("deiconified");

}

public void windowIconified(WindowEvent arg0) {

System.out.println("iconified");

}

public void windowOpened(WindowEvent arg0) {

System.out.println("opened");

}

Java Adapter Classes

Java adapter classes provide the default implementation of listener interfaces. If you inherit the adapter class, you will not be forced to provide the implementation of all the methods of listener interfaces. So it saves code.

The adapter classes are found in java.awt.event, java.awt.dnd and javax.swing.event packages. The Adapter classes with their corresponding listener interfaces are given below.

java.awt.event Adapter classes

Adapter class	Listener interface
WindowAdapter	WindowListener
KeyAdapter	KeyListener
MouseAdapter	MouseListener
MouseMotionAdapter	MouseMotionListener
FocusAdapter	FocusListener
ComponentAdapter	ComponentListener
ContainerAdapter	ContainerListener
HierarchyBoundsAdapter	HierarchyBoundsListener

java.awt.dnd Adapter classes

Adapter class	Listener interface
DragSourceAdapter	DragSourceListener
DragTargetAdapter	DragTargetListener

javax.swing.event Adapter classes

Adapter class	Listener interface
MouseInputAdapter	MouseInputListener
InternalFrameAdapter	InternalFrameListener

Java WindowAdapter Example

import java.awt.*;

import java.awt.event.*;

public class AdapterExample{

Frame f;

AdapterExample(){

f=new Frame("Window Adapter");

f.addWindowListener(new WindowAdapter(){

public void windowClosing(WindowEvent e) {

f.dispose();

}

});

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public static void main(String[] args) {

new AdapterExample();

}

Ex2:

import java.awt.*;

import java.awt.event.*;

public class MouseAdapterExample extends MouseAdapter{

Frame f;

MouseAdapterExample(){

f=new Frame("Mouse Adapter");

f.addMouseListener(this);

f.setSize(300,300);

f.setLayout(null);

f.setVisible(true);

}

public void mouseClicked(MouseEvent e) {

Graphics g=f.getGraphics();

g.setColor(Color.BLUE);

g.fillOval(e.getX(),e.getY(),30,30);

}

public static void main(String[] args) {

new MouseAdapterExample();

}

Java MouseMotionAdapter Example

import java.awt.*;

import java.awt.event.*;

public class MouseMotionAdapterExample extends MouseMotionAdapter{

Frame f;

MouseMotionAdapterExample(){

f=new Frame("Mouse Motion Adapter");

f.addMouseMotionListener(this);

f.setSize(300,300);

f.setLayout(null);

f.setVisible(true);

}

public void mouseDragged(MouseEvent e) {

Graphics g=f.getGraphics();

g.setColor(Color.ORANGE);

g.fillOval(e.getX(),e.getY(),20,20);

}

public static void main(String[] args) {

new MouseMotionAdapterExample();

}

Java KeyAdapter Example

import java.awt.*;

import java.awt.event.*;

public class KeyAdapterExample extends KeyAdapter{

Label l;

TextArea area;

Frame f;

KeyAdapterExample(){

f=new Frame("Key Adapter");

l=new Label();

l.setBounds(20,50,200,20);

area=new TextArea();

area.setBounds(20,80,300, 300);

area.addKeyListener(this);

f.add(l);f.add(area);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public void keyReleased(KeyEvent e) {

String text=area.getText();

String words[]=text.split("\\s");

l.setText("Words: "+words.length+" Characters:"+text.length());

}

public static void main(String[] args) {

new KeyAdapterExample();

}

How to close AWT Window in Java

We can close the AWT Window or Frame by calling dispose() or System.exit() inside windowClosing() method. The windowClosing() method is found in WindowListener interface and WindowAdapter class.

The WindowAdapter class implements WindowListener interfaces. It provides the default implementation of all the 7 methods of WindowListener interface. To override the windowClosing() method, you can either use WindowAdapter class or WindowListener interface.

If you implement the WindowListener interface, you will be forced to override all the 7 methods of WindowListener interface. So it is better to use WindowAdapter class.

Different ways to override windowClosing() method

There are many ways to override windowClosing() method:

By anonymous class
By inheriting WindowAdapter class
By implementing WindowListener interface

Close AWT Window Example 1: Anonymous class

import java.awt.*;

import java.awt.event.WindowEvent;

import java.awt.event.WindowListener;

public class WindowExample extends Frame{

WindowExample(){

addWindowListener(new WindowAdapter(){

public void windowClosing(WindowEvent e) {

dispose();

}

});

setSize(400,400);

setLayout(null);

setVisible(true);

}

public static void main(String[] args) {

new WindowExample();

}

Close AWT Window Example 2: extending WindowAdapter

import java.awt.*;

import java.awt.event.*;

public class AdapterExample extends WindowAdapter{

Frame f;

AdapterExample(){

f=new Frame();

f.addWindowListener(this);

f.setSize(400,400);

f.setLayout(null);

f.setVisible(true);

}

public void windowClosing(WindowEvent e) {

f.dispose();

}

public static void main(String[] args) {

new AdapterExample();

}

By implementing WindowListener interface

import java.awt.*;

import java.awt.event.WindowEvent;

import java.awt.event.WindowListener;

public class WindowExample extends Frame implements WindowListener{

WindowExample(){

addWindowListener(this);

setSize(400,400);

setLayout(null);

setVisible(true);

}

public static void main(String[] args) {

new WindowExample();

}

public void windowActivated(WindowEvent e) {}

public void windowClosed(WindowEvent e) {}

public void windowClosing(WindowEvent e) {

dispose();

}

public void windowDeactivated(WindowEvent e) {}

public void windowDeiconified(WindowEvent e) {}

public void windowIconified(WindowEvent e) {}

public void windowOpened(WindowEvent arg0) {}

}