java - Midi 音序器异常

Question

我正在尝试以下操作，

 MidiDevice.Info[] devices = MidiSystem.getMidiDeviceInfo();
        if (devices.length == 0) {
            System.out.println("No MIDI devices found");
        } else {
            for (MidiDevice.Info dev : devices) {
                System.out.println(dev);
            }
        }

        Sequencer player = MidiSystem.getSequencer();
        player.open();

但是，我得到以下信息，

Real Time Sequencer
javax.sound.midi.MidiUnavailableException
at javax.sound.midi.MidiSystem.getDefaultDeviceWrapper(MidiSystem.java:1078)
at javax.sound.midi.MidiSystem.getReceiver(MidiSystem.java:240)
at javax.sound.midi.MidiSystem.getSequencer(MidiSystem.java:442)
at javax.sound.midi.MidiSystem.getSequencer(MidiSystem.java:348)
at MidiPlayTest.play(MidiPlayTest.java:23)
at MidiPlayTest.main(MidiPlayTest.java:56)
Caused by: java.lang.IllegalArgumentException: Requested device not installed
at javax.sound.midi.MidiSystem.getDefaultDevice(MidiSystem.java:1130)
at javax.sound.midi.MidiSystem.getDefaultDeviceWrapper(MidiSystem.java:1076)
... 5 more

Answer 1

嗯，似乎有 Midi 设备，但这些设备不可用，如 MidiUnavailableException 所示。

查看该异常的来源，即您对 MidiSystem.getSequencer() 的调用。在 JavaDoc在该方法中，您会发现以下内容:

Throws:
MidiUnavailableException - if the sequencer is not available due to resource restrictions, or no sequencer is installed in the system, or if connected is true, and there is no Receiver available by any installed MidiDevice

从那里继续，即查看哪种情况可能导致该异常。