Java Language Audio Play a MIDI file
Example
MIDI files can be played by using several classes from the javax.sound.midi package. A Sequencer performs playback of the MIDI file, and many of its methods can be used to set playback controls such as loop count, tempo, track muting, and others.
General playback of MIDI data can be done in this way:
import java.io.File;
import java.io.IOException;
import javax.sound.midi.InvalidMidiDataException;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.MidiUnavailableException;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
public class MidiPlayback {
public static void main(String[] args) {
try {
Sequencer sequencer = MidiSystem.getSequencer(); // Get the default Sequencer
if (sequencer==null) {
System.err.println("Sequencer device not supported");
return;
}
sequencer.open(); // Open device
// Create sequence, the File must contain MIDI file data.
Sequence sequence = MidiSystem.getSequence(new File(args[0]));
sequencer.setSequence(sequence); // load it into sequencer
sequencer.start(); // start the playback
} catch (MidiUnavailableException | InvalidMidiDataException | IOException ex) {
ex.printStackTrace();
}
}
}
To stop the playback use:
sequencer.stop(); // Stop the playback
A sequencer can be set to mute one or more of the sequence's tracks during playback so none of the instruments in those specified play. The following example sets the first track in the sequence to be muted:
import javax.sound.midi.Track;
// ...
Track[] track = sequence.getTracks();
sequencer.setTrackMute(track[0]);
A sequencer can play a sequence repeatedly if the loop count is given. The following sets the sequencer to play a sequence four times and indefinitely:
sequencer.setLoopCount(3);
sequencer.setLoopCount(Sequencer.LOOP_CONTINUOUSLY);
The sequencer does not always have to play the sequence from the beginning, nor does it have to play the sequence until the end. It can start and end at any point by specifying the tick in the sequence to start and end at. It is also possible to specify manually which tick in the sequence the sequencer should play from:
sequencer.setLoopStartPoint(512);
sequencer.setLoopEndPoint(32768);
sequencer.setTickPosition(8192);
Sequencers can also play a MIDI file at a certain tempo, which can be controlled by specifying the tempo in beats per minute (BPM) or microseconds per quarter note (MPQ). The factor at which the sequence is played can be adjusted as well.
sequencer.setTempoInBPM(1250f);
sequencer.setTempoInMPQ(4750f);
sequencer.setTempoFactor(1.5f);
When you finished using the Sequencer, remeber to close it
sequencer.close();
