Java Tutorial/J2ME/MIDI

Controllable MIDI

import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Gauge;
import javax.microedition.lcdui.Item;
import javax.microedition.lcdui.ItemStateListener;
import javax.microedition.media.Manager;
import javax.microedition.media.Player;
import javax.microedition.media.control.PitchControl;
import javax.microedition.media.control.TempoControl;
import javax.microedition.media.control.VolumeControl;
import javax.microedition.midlet.MIDlet;
public class ControllableMIDIMIDlet extends MIDlet implements ItemStateListener {
  Player midiPlayer = null;
  VolumeControl volControl = null;
  PitchControl pitchControl = null;
  TempoControl tempoControl = null;
  Form form = new Form("MIDI Player", null);
  Gauge volGauge = new Gauge("Volume: 50", true, 100, 50);
  Gauge pitchGauge = new Gauge("Pitch: 0", true, 10, 5);
  Gauge tempoGauge = new Gauge("Tempo: 120", true, 30, 12);
  public ControllableMIDIMIDlet() {
    try {
      midiPlayer = Manager.createPlayer(getClass().getResourceAsStream("/a.mid"), "audio/midi");
      midiPlayer.prefetch();
      volControl = (VolumeControl) midiPlayer.getControl("javax.microedition.media.control.VolumeControl");
      pitchControl = (PitchControl) midiPlayer.getControl("javax.microedition.media.control.PitchControl");
      tempoControl = (TempoControl) midiPlayer.getControl("javax.microedition.media.control.TempoControl");
      form.append(volGauge);
      form.append(tempoGauge);
      form.append(pitchGauge);
      form.setItemStateListener(this);
      Display.getDisplay(this).setCurrent(form);
    } catch (Exception e) {
      System.err.println(e);
    }
  }
  public void itemStateChanged(Item item) {
    if (!(item instanceof Gauge))
      return;
    Gauge gauge = (Gauge) item;
    int val = gauge.getValue();
    if (item == volGauge) {
      volControl.setLevel(val);
      volGauge.setLabel("Volume: " + val);
    }
    if (item == tempoGauge && tempoControl != null) {
      tempoControl.setTempo((val) * 10 * 1000);
      tempoGauge.setLabel("Tempo: " + (val * 10));
    }
    if (item == pitchGauge && pitchControl != null) {
      pitchControl.setPitch((val - 5) * 12 * 1000);
      pitchGauge.setLabel("Pitch: " + (val - 5));
    }
  }
  public void startApp() {
    try {
      if (midiPlayer != null) {
        midiPlayer.start();
      }
    } catch (Exception e) {
      System.err.println(e);
    }
  }
  public void pauseApp() {
    try {
      if (midiPlayer != null) {
        midiPlayer.stop();
      }
    } catch (Exception e) {
      System.err.println(e);
    }
  }
  public void destroyApp(boolean unconditional) {
    try {
      if (midiPlayer != null) {
        midiPlayer.close();
      }
    } catch (Exception e) {
      System.err.println(e);
    }
  }
}

MIDI Capabilities

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.AlertType;
import javax.microedition.lcdui.Display;
import javax.microedition.media.Manager;
import javax.microedition.media.Player;
import javax.microedition.media.control.MIDIControl;
import javax.microedition.midlet.MIDlet;
public class MIDICapabilitiesMIDlet extends MIDlet {
  public void startApp() {
    try {
      Player p = Manager.createPlayer(Manager.MIDI_DEVICE_LOCATOR);
      p.prefetch();
      MIDIControl mControl = (MIDIControl) p
          .getControl("javax.microedition.media.control.MIDIControl");
      String msg = mControl.isBankQuerySupported() ? "MIDIControl is fully supported"
          : "Minimum MIDIControl is provided";
      Display.getDisplay(this).setCurrent(new Alert("Message", msg, null, AlertType.INFO));
    } catch (Exception e) {
      System.err.println(e);
    }
  }
  public void pauseApp() {
  }
  public void destroyApp(boolean unconditional) {
  }
}

MIDI Events

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.Display;
import javax.microedition.media.Manager;
import javax.microedition.media.Player;
import javax.microedition.media.control.MIDIControl;
import javax.microedition.midlet.MIDlet;
public class MIDIEventsMIDlet extends MIDlet {
  Display display = null;
  Alert alert = new Alert("Message");
  public MIDIEventsMIDlet() {
    display = Display.getDisplay(this);
    alert.setString("Working...");
    alert.setTimeout(Alert.FOREVER);
  }
  public void startApp() {
    display.setCurrent(alert);
    try {
      Player p = Manager.createPlayer(Manager.MIDI_DEVICE_LOCATOR);
      p.prefetch();
      MIDIControl mControl = (MIDIControl) p
          .getControl("javax.microedition.media.control.MIDIControl");
      if (mControl == null)
        throw new Exception("MIDIControl not available");
      mControl.shortMidiEvent(MIDIControl.NOTE_ON | 11, 60, 100);
      Thread.sleep(100);
      mControl.shortMidiEvent(192 | 11, 14, 0);
      Thread.sleep(100);
      mControl.shortMidiEvent(MIDIControl.CONTROL_CHANGE | 11, 7, 50);
      Thread.sleep(100);
      mControl.shortMidiEvent(MIDIControl.NOTE_ON | 11, 60, 0);
    } catch (Exception e) {
      alert.setString(e.getMessage());
    }
  }
  public void pauseApp() {
  }
  public void destroyApp(boolean unconditional) {
  }
}

Mixing Audio

import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.media.Manager;
import javax.microedition.media.Player;
import javax.microedition.media.control.MIDIControl;
import javax.microedition.midlet.MIDlet;
public class MixingAudioMIDlet extends MIDlet implements CommandListener {
  private Player backgroundPlayer = null;
  private Player firePlayer = null;
  private Player jumpPlayer = null;
  private MIDIControl mControl = null;
  private Display display = null;
  private Alert alert = new Alert("Message");
  private Command exitCommand = new Command("Exit", Command.EXIT, 1);
  private Command fireCommand = new Command("Fire!", Command.SCREEN, 1);
  private Command jumpCommand = new Command("Jump!", Command.SCREEN, 1);
  public MixingAudioMIDlet() {
    display = Display.getDisplay(this);
    alert.setString("Playing background score");
    alert.setTimeout(Alert.FOREVER);
    alert.addCommand(exitCommand);
    alert.addCommand(fireCommand);
    alert.addCommand(jumpCommand);
    alert.setCommandListener(this);
    initPlayers();
  }
  private void initPlayers() {
    try {
      backgroundPlayer = Manager.createPlayer(getClass().getResourceAsStream("/a.mid"),
          "audio/midi");
      backgroundPlayer.prefetch();
      backgroundPlayer.setLoopCount(-1);
      firePlayer = Manager.createPlayer(Manager.MIDI_DEVICE_LOCATOR);
      firePlayer.prefetch();
      mControl = (MIDIControl) firePlayer
          .getControl("javax.microedition.media.control.MIDIControl");
      mControl.setProgram(11, -1, 127);
      jumpPlayer = Manager.createPlayer(getClass().getResourceAsStream(
          "/p.wav"), "audio/x-wav");
      jumpPlayer.prefetch();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  public void startApp() {
    try {
      if (backgroundPlayer != null) {
        backgroundPlayer.start();
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
    display.setCurrent(alert);
  }
  public void commandAction(Command cmd, Displayable disp) {
    if (cmd == exitCommand) {
      destroyApp(true);
      notifyDestroyed();
      return;
    }
    try {
      if (cmd == fireCommand) {
        mControl.shortMidiEvent(MIDIControl.NOTE_ON | 11, 60, 100);
      }
      if (cmd == jumpCommand) {
        jumpPlayer.start();
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  public void pauseApp() {
    try {
      if (backgroundPlayer != null)
        backgroundPlayer.stop();
      if (firePlayer != null)
        firePlayer.stop();
      if (jumpPlayer != null)
        jumpPlayer.stop();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  public void destroyApp(boolean unconditional) {
    try {
      if (backgroundPlayer != null) {
        backgroundPlayer.close();
        backgroundPlayer = null;
      }
      if (firePlayer != null) {
        firePlayer.close();
        firePlayer = null;
      }
      if (jumpPlayer != null) {
        jumpPlayer.close();
        jumpPlayer = null;
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

Play MIDI

import javax.microedition.media.Manager;
import javax.microedition.media.Player;
import javax.microedition.midlet.MIDlet;
public class PlayMIDIMIDlet extends MIDlet {
  Player midiPlayer = null;
  public PlayMIDIMIDlet() {
    try {
      midiPlayer = Manager.createPlayer(getClass().getResourceAsStream("/a.mid"), "audio/midi");
    } catch (Exception e) {
      System.err.println(e);
    }
  }
  public void startApp() {
    try {
      if (midiPlayer != null) {
        midiPlayer.start();
      }
    } catch (Exception e) {
      System.err.println(e);
    }
  }
  public void pauseApp() {
  }
  public void destroyApp(boolean unconditional) {
  }
}