Java将Midi消息发送到设备 [英] Java send midi message to device

问题描述

我有一个连接到树莓派的APC40 MkII.在pi上，我正在运行Java.使用java.sound.midi包，我可以毫无问题地建立与APC的连接并接收其Midi消息.但是经过大量研究，我仍然不知如何向APC发送Midi消息.

I have an APC40 MkII connected to a raspberry pi. On the pi, I have java running. With the java.sound.midi package, I can establish a connection to the APC and receive its midi messages without a problem. But after a lot of research I somehow still don't get how I can send midi messages to the APC.

这是我到目前为止的代码:

Here is the code I have so far:

package lightorgansandbox;

import javax.sound.midi.*;
import java.util.List;


public class MidiHandler {

public MidiHandler() {
    MidiDevice device;
    MidiDevice.Info[] infos = MidiSystem.getMidiDeviceInfo();

    for (MidiDevice.Info info : infos) {

        System.out.println("Info: '" + info.toString() + "'");

        try {
            device = MidiSystem.getMidiDevice(info);

            List<Transmitter> transmitters = device.getTransmitters();

            for(int j = 0; j<transmitters.size();j++) {
                transmitters.get(j).setReceiver(new MidiInputReceiver(device.getDeviceInfo().toString()));
            }  

            Transmitter trans = device.getTransmitter();
            trans.setReceiver(new MidiInputReceiver(device.getDeviceInfo().toString()));

            device.open();

        }catch (MidiUnavailableException e) {}
    }
}

public class MidiInputReceiver implements Receiver {

    public String name;

    public MidiInputReceiver(String name) {
        this.name = name;
    }

    public void send(MidiMessage msg, long timeStamp) {

        if (msg instanceof ShortMessage) {
            ShortMessage shortMessage = (ShortMessage) msg;

            int channel = shortMessage.getChannel();
            int pitch = shortMessage.getData1();
            int vel = shortMessage.getData2();
            System.out.println("Channel: " + channel);
            System.out.println("Pitch: " + pitch);
            System.out.println("vel: " + vel);

        }

    }

    public void close() {}

}

}

这一切都按照我想要的方式工作.但是我可以在哪里发送消息回设备?

This all works just the way I want. But where in this can I send a message back to the device?

推荐答案

只需将消息发送到设备的接收者. 从文档:

Just send the message to the device's receiver. From the documentation:

  Receiver rcvr = MidiSystem.getReceiver();  /* or device.getReceiver() */

  ShortMessage myMsg = new ShortMessage();
  myMsg.setMessage(ShortMessage.NOTE_ON, 0, 60, 93);
  long timeStamp = -1;
  rcvr.send(myMsg, timeStamp);

这篇关于Java将Midi消息发送到设备的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！