Add basis for MIDI - Communicator, Listener, and Note

src/main/java/sh/ball/audio/midi/MidiCommunicator.java

@@ -0,0 +1,71 @@
+package sh.ball.audio.midi;// Java program showing the implementation of a simple record
+
+import javax.sound.midi.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MidiCommunicator implements Runnable {
+
+  private final List<MidiDevice> devices = new ArrayList<>();
+  private final List<MidiListener> listeners = new ArrayList<>();
+
+  public static void main(String[] args) {
+    MidiCommunicator communicator = new MidiCommunicator();
+    communicator.run();
+  }
+
+  @Override
+  public void run() {
+    MidiDevice.Info[] infos = MidiSystem.getMidiDeviceInfo();
+    for (MidiDevice.Info info : infos) {
+      try {
+        MidiDevice device = MidiSystem.getMidiDevice(info);
+        List<Transmitter> transmitters = device.getTransmitters();
+
+        transmitters.forEach(t -> t.setReceiver(
+          new MidiInputReceiver(this)
+        ));
+
+        Transmitter trans = device.getTransmitter();
+        trans.setReceiver(new MidiInputReceiver(this));
+
+        device.open();
+        devices.add(device);
+        System.out.println(device.getDeviceInfo() + " Was Opened");
+
+
+      } catch (MidiUnavailableException ignored) {
+      }
+    }
+  }
+
+  public void addListener(MidiListener listener) {
+    listeners.add(listener);
+  }
+
+  private void notifyListeners(int status, MidiNote note, int pressure) {
+    for (MidiListener listener : listeners) {
+      listener.sendMidiMessage(status, note, pressure);
+    }
+    System.out.println(status);
+    System.out.println(note);
+    System.out.println(pressure);
+  }
+
+  public void stop() {
+    devices.forEach(MidiDevice::close);
+  }
+
+  private record MidiInputReceiver(
+    MidiCommunicator communicator) implements Receiver {
+
+    public void send(MidiMessage message, long timeStamp) {
+      byte[] rawMessage = message.getMessage();
+      communicator.notifyListeners(message.getStatus(), new MidiNote(rawMessage[1]), rawMessage[2]);
+    }
+
+    public void close() {
+    }
+  }
+}

src/main/java/sh/ball/audio/midi/MidiListener.java

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+package sh.ball.audio.midi;
+
+public interface MidiListener {
+
+  void sendMidiMessage(int status, MidiNote note, int pressure);
+}

src/main/java/sh/ball/audio/midi/MidiNote.java

@@ -0,0 +1,41 @@
+package sh.ball.audio.midi;
+
+import java.util.Objects;
+
+public class MidiNote {
+
+  private static final String[] NOTE_NAMES = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
+
+  private final String name;
+  private final int key;
+  private final int octave;
+
+  public MidiNote(int key) {
+    this.key = key;
+    this.octave = (key / 12)-1;
+    int note = key % 12;
+    this.name = NOTE_NAMES[note];
+  }
+
+  public int getKey() {
+    return key;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    MidiNote midiNote = (MidiNote) o;
+    return key == midiNote.key && octave == midiNote.octave && name.equals(midiNote.name);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(name, key, octave);
+  }
+
+  @Override
+  public String toString() {
+    return "Note -> " + this.name + this.octave + " key=" + this.key;
+  }
+}