Java MIDI：將MIDI鍵盤連接到默認合成器

Question

我得到一個MIDI鍵盤。 我只想要一個例子，說明如何在播放鍵盤時設置默認軟件合成器來播放聲音。

package cleffsgame; 

import java.util.logging.Level; 
import java.util.logging.Logger; 
import javax.sound.midi.MidiDevice; 
import javax.sound.midi.MidiSystem; 
import javax.sound.midi.MidiUnavailableException; 

public class CheckDevices { 

    public static void main(String[] args) { 
     MidiDevice device; 
     // display each device's properties 
     for (MidiDevice.Info info: MidiSystem.getMidiDeviceInfo()) { 

      try { 
       device = MidiSystem.getMidiDevice(info); 

       System.out.println("\nDevice: "); 
       System.out.println("Name: " + device.getDeviceInfo().getName()); 
       System.out.println("Vendor: " + device.getDeviceInfo().getVendor()); 
       System.out.println("Version: " + device.getDeviceInfo().getVersion()); 
       System.out.println("Description: " + device.getDeviceInfo().getDescription()); 
       System.out.println("Transmitters: " + device.getMaxTransmitters()); 
       System.out.println("Receivers: " + device.getMaxReceivers()); 

      } catch (MidiUnavailableException ex) { 
       Logger.getLogger(CheckDevices.class.getName()).log(Level.SEVERE, null, ex); 
      } 
     } 
    } 
} 

通過運行上面的代碼，我得到以下輸出：

運行：

設備：名稱：Gervill供應商：OpenJDK的版本：1.0說明： 軟件MIDI合成器變送器： 0接收器：-1

裝置：名稱：氧氣49銷售商：M-Audio版本：未知版本 描述：氧氣49發射器：-1接收器：0

設備：名稱：Oxygen 49廠商：M-Audio的版本：版本未知 說明：氧氣49個變送器：0接收器：-1

設備：名稱：實時測序供應商：Oracle公司版本： 版本1.0描述：軟件定序變送器：-1 接收機：-1 BUILD SUCCESSFUL（總時間：2秒）

但是當我運行下面的代碼，當我打鍵沒有播放聲音。

package cleffsgame; 

import java.util.logging.Level; 
import java.util.logging.Logger; 
import javax.sound.midi.MidiDevice; 
import javax.sound.midi.MidiSystem; 
import javax.sound.midi.MidiUnavailableException; 
import javax.sound.midi.Receiver; 
import javax.sound.midi.Synthesizer; 
import javax.sound.midi.Transmitter; 

/** 
* 
* @author umberto 
*/ 
public class Test { 

    public static void main(String[] args) { 
     MidiDevice inputDevice = null, synthDevice = null; 
     Transmitter transmitter = null; 
     Synthesizer synthesizer = null; 
     Receiver receiver = null; 

     try { 
      inputDevice = MidiSystem.getMidiDevice(MidiSystem.getMidiDeviceInfo()[1]); 
      synthDevice = MidiSystem.getMidiDevice(MidiSystem.getMidiDeviceInfo()[0]); 

     } catch (MidiUnavailableException ex) { 
      Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex); 
     } 

     // goodDevice must be Oxygen 49 transmitter (MIDI Input) 
     if (inputDevice != null && synthDevice != null) { 
      try { 
       transmitter = inputDevice.getTransmitter(); 
       System.out.println("Transmitter: " + inputDevice.getDeviceInfo()); 
       System.out.println(String.format("T/R: %s/%s", inputDevice.getMaxTransmitters(), inputDevice.getMaxReceivers())); 

       receiver = synthDevice.getReceiver(); 
       System.out.println("Receiver: " + synthDevice.getDeviceInfo()); 
       System.out.println(String.format("T/R: %s/%s", synthDevice.getMaxTransmitters(), synthDevice.getMaxReceivers())); 

       transmitter.setReceiver(receiver); 
       System.out.println("GoodDevice is open... check sound\n"); 
       inputDevice.open(); 
       synthDevice.open(); 

      } catch (Exception ex) { 
       Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex); 
      } 
     } 

    } 


} 

似乎有更多的事情要做比Synthesizer.receiver連接到InputDevice.transmitter因爲我從文檔https://docs.oracle.com/javase/tutorial/sound/MIDI-synth.html了。

Answer 1

在獲取發射器/接收器之前打開設備可能是個好主意。

但實際的問題是，該程序立即退出，所以設備沒有打開一段有用的時間。