Download Adding Sounds to Java Applications

ADDING SOUND TO JAVA APPLICATIONS
It’s now time to add sound effects to our programs. Fortunately, Java
provides built-in support for playing sound and music files. Java supports
a variety of audio formats, including WAV files in several formats (WAV,
AU, RMF, and AIFF) and MIDI files. WAV files are usually used to add
specific sound effects to your program, whereas MIDI files let you play
music while your program is running.
PLAYING A SOUND FILE
In order to get sound files to work, you will need to import the java.io and sun.audio packages.
The java.io package is necessary since you will need to use the InputStream class to get the audio file
that you want to use.
The sun.audio package is necessary because you will need to use the AudioStream and AudioPlayer,
and classes.
The following program will include a PLAY button to start playing the sound file and a STOP button to
stop playing the sound file. However, in this first example, we will not be looping the sound file; this will
happen in the next section of the lesson.
import
import
import
import
import
java.io.*;
sun.audio.*;
javax.swing.*;
java.awt.event.*;
java.awt.*;
public class SoundExample extends JFrame implements ActionListener {
private
private
private
private
JButton btnPlay, btnStop;
AudioStream auStream;
AudioPlayer auPlayer;
InputStream in;
public static void main(String[] args) {
new SoundExample();
}
public SoundExample() {
// Declare and initialize an AudioPlayer object
auPlayer = AudioPlayer.player;
// Add the components to your interface
btnPlay = new JButton("PLAY");
btnPlay.setPreferredSize(new Dimension(100, 30));
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btnPlay.setFocusable(false);
btnPlay.addActionListener(this);
btnStop = new JButton("STOP");
btnStop.setPreferredSize(new Dimension(100, 30));
btnStop.setFocusable(false);
btnStop.addActionListener(this);
JPanel panel = new JPanel();
panel.add(Box.createRigidArea(new Dimension(275, 30)));
panel.add(btnPlay);
panel.add(btnStop);
setContentPane(panel);
setSize(500, 150);
setTitle("Playing Sounds");
setLocationRelativeTo(null);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == btnPlay)
{
try
{
// Initialize the InputStream object with the sound file you
want to use
in = new FileInputStream(new File("glass_ping.wav"));
// Initialize the AudioStream object by passing the
InputStream object
auStream = new AudioStream(in);
}
catch(IOException e)
{
// Catch the exception that gets thrown if the file cannot
be retrieved
System.out.println(e.getMessage());
}
// Play the audio file
auPlayer.start(auStream);
}
else
{
// Stop the audio file
auPlayer.stop(auStream);
}
}
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When you run the program and click the PLAY button, the audio clip will play once for as long as the
audio clip lasts. Each time the user clicks the PLAY button, the audio clip will play.
LOOPING A SOUND FILE
The above example only plays the audio clip once when the user clicks the START button. In some
cases, you may want or need an audio clip to play continuously (for example, if you wanted to add
background music to a game).
Looping a sound file requires two additional objects: an AudioData object and a
ContinuousAudioDataStream object (both of which are included in the sun.audio package.
The following code will continuously loop an audio file once the user clicks the START button and stop
the file from playing when the user clicks the STOP button:
import
import
import
import
import
java.io.*;
sun.audio.*;
javax.swing.*;
java.awt.event.*;
java.awt.*;
public class SoundExample extends JFrame implements ActionListener {
private
private
private
private
private
private
JButton btnStart, btnStop;
AudioStream auStream;
AudioPlayer auPlayer;
InputStream in;
AudioData auData;
ContinuousAudioDataStream auLoop;
public static void main(String[] args) {
new SoundExample();
}
public SoundExample() {
// Declare and initialize an AudioPlayer object
auPlayer = AudioPlayer.player;
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// Add the components to your interface
btnStart = new JButton("START");
btnStart.setPreferredSize(new Dimension(100, 30));
btnStart.setFocusable(false);
btnStart.addActionListener(this);
btnStop = new JButton("STOP");
btnStop.setPreferredSize(new Dimension(100, 30));
btnStop.setFocusable(false);
btnStop.addActionListener(this);
JPanel panel = new JPanel();
panel.add(Box.createRigidArea(new Dimension(275, 30)));
panel.add(btnStart);
panel.add(btnStop);
setContentPane(panel);
setSize(300, 150);
setLocationRelativeTo(null);
setResizable(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == btnStart)
{
try
{
// Initialize the InputStream object with the sound file you
want to use
in = new FileInputStream(new File("glass_ping.wav"));
// Initialize the AudioStream object by passing the
InputStream object
auStream = new AudioStream(in);
// Initialize the AudioData object by calling the getData()
method included in the AudioStream class
auData = auStream.getData();
// Initialize the ContinuousAudioDataStream object by
passing the AudioData object
auLoop = new ContinuousAudioDataStream(auData);
}
catch(IOException e)
{
// Catch the exception that gets thrown if the file cannot
be retrieved
System.out.println(e.getMessage());
}
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// Play the audio file
auPlayer.start(auLoop);
}
else
{
// Stop the audio file
auPlayer.stop(auLoop);
}
}
}
Now when you run the program and click the START button, the audio file will play continuously until the
user clicks the STOP button.
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