Java tutorial
/* * Copyright (c) 2004 David Flanagan. All rights reserved. * This code is from the book Java Examples in a Nutshell, 3nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose, * including teaching and use in open-source projects. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book, * please visit http://www.davidflanagan.com/javaexamples3. */ import java.io.File; import java.io.IOException; import javax.sound.midi.InvalidMidiDataException; import javax.sound.midi.MetaEventListener; import javax.sound.midi.MetaMessage; import javax.sound.midi.MidiEvent; import javax.sound.midi.MidiSystem; import javax.sound.midi.MidiUnavailableException; import javax.sound.midi.Sequence; import javax.sound.midi.Sequencer; import javax.sound.midi.ShortMessage; import javax.sound.midi.Synthesizer; import javax.sound.midi.Track; public class PlayerPiano { // These are some MIDI constants from the spec. They aren't defined // for us in javax.sound.midi. public static final int DAMPER_PEDAL = 64; public static final int DAMPER_ON = 127; public static final int DAMPER_OFF = 0; public static final int END_OF_TRACK = 47; public static void main(String[] args) throws MidiUnavailableException, InvalidMidiDataException, IOException { int instrument = 0; int tempo = 120; String filename = null; // Parse the options // -i <instrument number> default 0, a piano. Allowed values: 0-127 // -t <beats per minute> default tempo is 120 quarter notes per minute // -o <filename> save to a midi file instead of playing int a = 0; while (a < args.length) { if (args[a].equals("-i")) { instrument = Integer.parseInt(args[a + 1]); a += 2; } else if (args[a].equals("-t")) { tempo = Integer.parseInt(args[a + 1]); a += 2; } else if (args[a].equals("-o")) { filename = args[a + 1]; a += 2; } else break; } char[] notes = args[a].toCharArray(); // 16 ticks per quarter note. Sequence sequence = new Sequence(Sequence.PPQ, 16); // Add the specified notes to the track addTrack(sequence, instrument, tempo, notes); if (filename == null) { // no filename, so play the notes // Set up the Sequencer and Synthesizer objects Sequencer sequencer = MidiSystem.getSequencer(); sequencer.open(); Synthesizer synthesizer = MidiSystem.getSynthesizer(); synthesizer.open(); sequencer.getTransmitter().setReceiver(synthesizer.getReceiver()); // Specify the sequence to play, and the tempo to play it at sequencer.setSequence(sequence); sequencer.setTempoInBPM(tempo); // Let us know when it is done playing sequencer.addMetaEventListener(new MetaEventListener() { public void meta(MetaMessage m) { // A message of this type is automatically sent // when we reach the end of the track if (m.getType() == END_OF_TRACK) System.exit(0); } }); // And start playing now. sequencer.start(); } else { // A file name was specified, so save the notes int[] allowedTypes = MidiSystem.getMidiFileTypes(sequence); if (allowedTypes.length == 0) { System.err.println("No supported MIDI file types."); } else { MidiSystem.write(sequence, allowedTypes[0], new File(filename)); System.exit(0); } } } static final int[] offsets = { // add these amounts to the base value // A B C D E F G -4, -2, 0, 1, 3, 5, 7 }; /* * This method parses the specified char[] of notes into a Track. The musical * notation is the following: A-G: A named note; Add b for flat and # for * sharp. +: Move up one octave. Persists. -: Move down one octave. Persists. * /1: Notes are whole notes. Persists 'till changed /2: Half notes /4: * Quarter notes /n: N can also be, 8, 16, 32, 64. s: Toggle sustain pedal on * or off (initially off) * >: Louder. Persists <: Softer. Persists .: Rest. Length depends on current * length setting Space: Play the previous note or notes; notes not separated * by spaces are played at the same time */ public static void addTrack(Sequence s, int instrument, int tempo, char[] notes) throws InvalidMidiDataException { Track track = s.createTrack(); // Begin with a new track // Set the instrument on channel 0 ShortMessage sm = new ShortMessage(); sm.setMessage(ShortMessage.PROGRAM_CHANGE, 0, instrument, 0); track.add(new MidiEvent(sm, 0)); int n = 0; // current character in notes[] array int t = 0; // time in ticks for the composition // These values persist and apply to all notes 'till changed int notelength = 16; // default to quarter notes int velocity = 64; // default to middle volume int basekey = 60; // 60 is middle C. Adjusted up and down by octave boolean sustain = false; // is the sustain pedal depressed? int numnotes = 0; // How many notes in current chord? while (n < notes.length) { char c = notes[n++]; if (c == '+') basekey += 12; // increase octave else if (c == '-') basekey -= 12; // decrease octave else if (c == '>') velocity += 16; // increase volume; else if (c == '<') velocity -= 16; // decrease volume; else if (c == '/') { char d = notes[n++]; if (d == '2') notelength = 32; // half note else if (d == '4') notelength = 16; // quarter note else if (d == '8') notelength = 8; // eighth note else if (d == '3' && notes[n++] == '2') notelength = 2; else if (d == '6' && notes[n++] == '4') notelength = 1; else if (d == '1') { if (n < notes.length && notes[n] == '6') notelength = 4; // 1/16th note else notelength = 64; // whole note } } else if (c == 's') { sustain = !sustain; // Change the sustain setting for channel 0 ShortMessage m = new ShortMessage(); m.setMessage(ShortMessage.CONTROL_CHANGE, 0, DAMPER_PEDAL, sustain ? DAMPER_ON : DAMPER_OFF); track.add(new MidiEvent(m, t)); } else if (c >= 'A' && c <= 'G') { int key = basekey + offsets[c - 'A']; if (n < notes.length) { if (notes[n] == 'b') { // flat key--; n++; } else if (notes[n] == '#') { // sharp key++; n++; } } addNote(track, t, notelength, key, velocity); numnotes++; } else if (c == ' ') { // Spaces separate groups of notes played at the same time. // But we ignore them unless they follow a note or notes. if (numnotes > 0) { t += notelength; numnotes = 0; } } else if (c == '.') { // Rests are like spaces in that they force any previous // note to be output (since they are never part of chords) if (numnotes > 0) { t += notelength; numnotes = 0; } // Now add additional rest time t += notelength; } } } // A convenience method to add a note to the track on channel 0 public static void addNote(Track track, int startTick, int tickLength, int key, int velocity) throws InvalidMidiDataException { ShortMessage on = new ShortMessage(); on.setMessage(ShortMessage.NOTE_ON, 0, key, velocity); ShortMessage off = new ShortMessage(); off.setMessage(ShortMessage.NOTE_OFF, 0, key, velocity); track.add(new MidiEvent(on, startTick)); track.add(new MidiEvent(off, startTick + tickLength)); } }