【发布时间】:2018-07-09 02:03:13
【问题描述】:
我想将 Note_On 消息发送到一个名为 LoopBe (Link to Site) 的虚拟 Midi 接口。如何获取 Receiver 对象(Java)?
我尝试了下面的代码,但在 rcvr.send() 上出现 NullPointerException。
public class test {
public static Receiver rcvr;
public static void main(String[] args) throws InvalidMidiDataException, MidiUnavailableException {
String scene = "Test";
getReceiver();
ShortMessage myMsg = new ShortMessage();
// Nachricht Channel Note Lautstärke
myMsg.setMessage(ShortMessage.NOTE_ON, 0, 1, 127);
rcvr.send(myMsg, -1);
System.out.println("Szene " + scene + " ausgelöst");
}
public static void getReceiver() throws MidiUnavailableException {
MidiDevice.Info[] infos = MidiSystem.getMidiDeviceInfo();
for(Info devices : infos )
{
System.out.println(devices.getName() + " : " + devices.getDescription());
if(devices.getName() == "LoopBe Internal MIDI" && devices.getDescription() == "No details available") {
MidiDevice device = MidiSystem.getMidiDevice(devices);
rcvr = device.getReceiver();
System.out.println("Receiver: " + rcvr.toString());
}
}
}
}
我尝试了rcvr = MidiSystem.getReceiver(),它成功了,但它会将消息发送到 com.sun.media.sound.MidiOutDevice$MidiOutReceiver@404b9385。
【问题讨论】: