public class MidiSpielerei {

	private MidiSpielerei() { }

	private static de.humatic.mmj.MidiOutput openMidiPort(String port) {
        // hier sollte man eigentlich vorher MidiOutputs cachen

        de.humatic.mmj.MidiSystem.initMidiSystem(port, port);
		String[] outputNames = de.humatic.mmj.MidiSystem.getOutputs();

        int portIndex = -1;
        for (int i = 0; i < outputNames.length; i++) {
            if(outputNames[i].equals(port)) {
                portIndex = i;
                break;
            }
        }

        if(portIndex == -1) {
            throw new RuntimeException("could not open port!");
        }

        return de.humatic.mmj.MidiSystem.openMidiOutput(portIndex);
    }

	public static void playMidi(File midiFile, String portName) throws Exception {
		Sequencer sequencer = javax.sound.midi.MidiSystem.getSequencer();
		sequencer.open();

		Transmitter transmitter = sequencer.getTransmitter();
		de.humatic.mmj.MidiOutput output = openMidiPort(portName);
		transmitter.setReceiver(new MyReceiver(output));

		Sequence sequence = javax.sound.midi.MidiSystem.getSequence(midiFile);
		sequencer.setSequence(sequence);

		sequencer.addMetaEventListener(new MetaEventListener() {
			public void meta(MetaMessage meta) {
				if(meta.getType() == 47) {
					sequencer.stop();
					sequencer.close();
				}
			}

		});

		sequencer.start();
	}
}


class MyReceiver implements Receiver {
    de.humatic.mmj.private MidiOutput output;

    public MyReceiver(MidiOutput output) {
        this.output = output;
    }

    public void close() {
		// nothing to do
    }


    public void send(MidiMessage message, long timeStamp) {
        this.output.sendMidi(message.getMessage(), timeStamp);
    }

}