Using Andrew’s approach, here’s an example that plays an equal tempered scale.
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.SourceDataLine;
public class Tone {
public static void main(String[] args) throws LineUnavailableException {
final AudioFormat af =
new AudioFormat(Note.SAMPLE_RATE, 8, 1, true, true);
SourceDataLine line = AudioSystem.getSourceDataLine(af);
line.open(af, Note.SAMPLE_RATE);
line.start();
for (Note n : Note.values()) {
play(line, n, 500);
play(line, Note.REST, 10);
}
line.drain();
line.close();
}
private static void play(SourceDataLine line, Note note, int ms) {
ms = Math.min(ms, Note.SECONDS * 1000);
int length = Note.SAMPLE_RATE * ms / 1000;
int count = line.write(note.data(), 0, length);
}
}
enum Note {
REST, A4, A4$, B4, C4, C4$, D4, D4$, E4, F4, F4$, G4, G4$, A5;
public static final int SAMPLE_RATE = 16 * 1024; // ~16KHz
public static final int SECONDS = 2;
private byte[] sin = new byte[SECONDS * SAMPLE_RATE];
Note() {
int n = this.ordinal();
if (n > 0) {
double exp = ((double) n - 1) / 12d;
double f = 440d * Math.pow(2d, exp);
for (int i = 0; i < sin.length; i++) {
double period = (double)SAMPLE_RATE / f;
double angle = 2.0 * Math.PI * i / period;
sin[i] = (byte)(Math.sin(angle) * 127f);
}
}
}
public byte[] data() {
return sin;
}
}
This low-level approach may be suitable for older, less capable platforms. Also consider javax.sound.midi
; a complete example is shown here and the Synthesizing Sound tutorial is cited here.