How to play java?
I am developing a simple timer app, but I have some problems playing audio.
Here is my code
public class Timer {
private static int time = 0;
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Type the values");
System.out.print("Hours : ");
int hours = scanner.nextInt();
System.out.print("Minutes : ");
int minutes = scanner.nextInt();
System.out.print("Seconds : ");
int seconds = scanner.nextInt();
time = hours * 3600 + minutes * 60 + seconds;
new Thread() {
@Override
public void run() {
try {
while (time != 0) {
time--;
sleep(1000);
}
System.out.println("Time elapsed");
URL url = Timer.class.getResource("Timer.wav");
AudioInputStream audioIn = AudioSystem.getAudioInputStream(url);
Clip clip = AudioSystem.getClip();
clip.open(audioIn);
clip.start();
} catch (InterruptedException | UnsupportedAudioFileException | IOException | LineUnavailableException e) {
e.printStackTrace();
}
}
}.start();
System.out.println("Timer started");
}
}
And here is my project structure.
Now the problem is that the app is not giving me any exceptions even though it doesn't play audio. What's wrong?
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This is a multithreading problem.
The problem is that you start the clip, but then terminate your program, preventing it from playing with it. The method is Clip.start()
not a blocking operation, which means that it does not wait, but starts a new daemon thread to play sound - a daemon thread that is killed when the program exits the method main
.
Here is a sample code from my other answer , to play an audio file using Clip
. Notice how I calculate the duration of the sound and then sleep()
so that it plays.
import java.io.File;
import java.io.IOException;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;
public class PlaySound {
private static boolean tryToInterruptSound = false;
private static long mainTimeOut = 3000;
private static long startTime = System.currentTimeMillis();
public static synchronized Thread playSound(final File file) {
Thread soundThread = new Thread() {
@Override
public void run() {
try{
Clip clip = null;
AudioInputStream inputStream = null;
clip = AudioSystem.getClip();
inputStream = AudioSystem.getAudioInputStream(file);
AudioFormat format = inputStream.getFormat();
long audioFileLength = file.length();
int frameSize = format.getFrameSize();
float frameRate = format.getFrameRate();
long durationInMiliSeconds =
(long) (((float)audioFileLength / (frameSize * frameRate)) * 1000);
clip.open(inputStream);
clip.start();
System.out.println("" + (System.currentTimeMillis() - startTime) + ": sound started playing!");
Thread.sleep(durationInMiliSeconds);
while (true) {
if (!clip.isActive()) {
System.out.println("" + (System.currentTimeMillis() - startTime) + ": sound got to it end!");
break;
}
long fPos = (long)(clip.getMicrosecondPosition() / 1000);
long left = durationInMiliSeconds - fPos;
System.out.println("" + (System.currentTimeMillis() - startTime) + ": time left: " + left);
if (left > 0) Thread.sleep(left);
}
clip.stop();
System.out.println("" + (System.currentTimeMillis() - startTime) + ": sound stoped");
clip.close();
inputStream.close();
} catch (LineUnavailableException e) {
e.printStackTrace();
} catch (UnsupportedAudioFileException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
System.out.println("" + (System.currentTimeMillis() - startTime) + ": sound interrupted while playing.");
}
}
};
soundThread.setDaemon(true);
soundThread.start();
return soundThread;
}
public static void main(String[] args) {
Thread soundThread = playSound(new File("C:\\Booboo.wav"));
System.out.println("" + (System.currentTimeMillis() - startTime) + ": playSound returned, keep running the code");
try {
Thread.sleep(mainTimeOut );
} catch (InterruptedException e) {
e.printStackTrace();
}
if (tryToInterruptSound) {
try {
soundThread.interrupt();
Thread.sleep(1);
// Sleep in order to let the interruption handling end before
// exiting the program (else the interruption could be handled
// after the main thread ends!).
} catch (Exception e) {
e.printStackTrace();
}
}
System.out.println("" + (System.currentTimeMillis() - startTime) + ": End of main thread; exiting program " +
(soundThread.isAlive() ? "killing the sound deamon thread" : ""));
}
}
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The problem was that the app exited before the clip started playing. So I replaced my game block with this new one.
URL url = Timer.class.getResource("Timer.wav");
AudioInputStream audioIn = AudioSystem.getAudioInputStream(url);
AudioFormat format = audioIn.getFormat();
Clip clip = AudioSystem.getClip();
clip.open(audioIn);
clip.start();
long frames = audioIn.getFrameLength();
double durationInSeconds = (frames + 0.0) / format.getFrameRate();
sleep((long) durationInSeconds * 1000);
Now he waits until the clip plays and ends, and only then the application will terminate his work
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Edit: It might help if I read all the code before posting the lol response. So your class.getResource ("Timer.wav") should be class.getResource ("resources / Timer.wav"). I am assuming resources are a folder in your class structure. Also if you are using getResourceAsStream instead of getResource you can skip the url.
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You have to check if the resource was actually restored successfully:
URL url = Timer.class.getResource("Timer.wav");
if (url == null)
{
System.out.println("wav file resource not found!");
return;
}
// continue on
Also add an exception handler to your program to check if any exceptions have gone all the way to the top of your program:
Thread.setDefaultUncaughtExceptionHandler(new UncaughtExceptionHandler()
{
public void uncaughtException(Thread t, Throwable e)
{
String msg = "DefaultUncaughtExceptionHandler thread[" + t.getName() + "]";
System.out.println(msg);
e.printStackTrace(System.out);
System.err.println(msg);
e.printStackTrace(System.err);
}
});
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