/**
* Loads a sequence from an input stream. Returns null if an error occurs.
*
* @param is
* @return
*/
public Sequence getSequence(InputStream is) {
try {
if (!is.markSupported()) {
is = new BufferedInputStream(is);
}
Sequence s = MidiSystem.getSequence(is);
is.close();
return s;
} catch (InvalidMidiDataException ex) {
ex.printStackTrace();
return null;
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
}
/**
* Constructor. It breaks a Song into its MidiEvent components, and adds them together in order to
* create a MIDI file.
*
* @param song The song to export
*/
public MidiExporter() {
// Create the Sequence that will contain everything
try {
sequence = new Sequence(Sequence.PPQ, 2);
} catch (InvalidMidiDataException ex) {
ex.printStackTrace();
System.exit(1);
}
}
/**
* Plays a sequence, optionally looping. This method returns immediately. The sequence is not
* played if it is invalid.
*
* @param sequence
* @param loop
*/
public void play(Sequence sequence, boolean loop) {
if (sequencer != null && sequence != null && sequencer.isOpen()) {
try {
sequencer.setSequence(sequence);
sequencer.start();
this.loop = loop;
} catch (InvalidMidiDataException ex) {
ex.printStackTrace();
}
}
}
/** Carrega a seqüência do sistema de arquivos. Retorna null se um erro ocorrer. */
public Sequence getSequence(String name) {
String filename = "/recursos/sons/" + name;
try {
return MidiSystem.getSequence(getClass().getResource((filename)));
} catch (InvalidMidiDataException ex) {
ex.printStackTrace();
return null;
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
}
/**
* Create the MidiEvent for a note, given the data.
*
* @param command The command value for the ShortMessage
* @param note The MIDI value for the note to be played
* @param eventTime When this event should occur
* @param velocity The velocity of this note
* @return The MidiEvent for the note
*/
private MidiEvent createNoteEvent(int command, int note, int eventTime, int velocity) {
// Create the message and set its parameters to the ones given.
ShortMessage message = new ShortMessage();
try {
message.setMessage(command, 0, note, velocity);
} catch (InvalidMidiDataException ex) {
// Something went wrong.
ex.printStackTrace();
System.exit(1);
}
// Create the MidiEvent and return it.
return new MidiEvent(message, eventTime);
}
