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javax.sound.midi
public interface: MidiDevice [javadoc | source]

All Implemented Interfaces:
    AutoCloseable

All Known Implementing Classes:
    Sequencer, Synthesizer

MidiDevice is the base interface for all MIDI devices. Common devices include synthesizers, sequencers, MIDI input ports, and MIDI output ports.

A MidiDevice can be a transmitter or a receiver of MIDI events, or both. Therefore, it can provide Transmitter or Receiver instances (or both). Typically, MIDI IN ports provide transmitters, MIDI OUT ports and synthesizers provide receivers. A Sequencer typically provides transmitters for playback and receivers for recording.

A MidiDevice can be opened and closed explicitly as well as implicitly. Explicit opening is accomplished by calling #open , explicit closing is done by calling #close on the MidiDevice instance. If an application opens a MidiDevice explicitly, it has to close it explicitly to free system resources and enable the application to exit cleanly. Implicit opening is done by calling MidiSystem.getReceiver and MidiSystem.getTransmitter . The MidiDevice used by MidiSystem.getReceiver and MidiSystem.getTransmitter is implementation-dependant unless the properties javax.sound.midi.Receiver and javax.sound.midi.Transmitter are used (see the description of properties to select default providers in javax.sound.midi.MidiSystem ). A MidiDevice that was opened implicitly, is closed implicitly by closing the Receiver or Transmitter that resulted in opening it. If more than one implicitly opening Receiver or Transmitter were obtained by the application, the decive is closed after the last Receiver or Transmitter has been closed. On the other hand, calling getReceiver or getTransmitter on the device instance directly does not open the device implicitly. Closing these Transmitters and Receivers does not close the device implicitly. To use a device with Receivers or Transmitters obtained this way, the device has to be opened and closed explicitly.

If implicit and explicit opening and closing are mixed on the same MidiDevice instance, the following rules apply:

To detect if a MidiDevice represents a hardware MIDI port, the following programming technique can be used:
MidiDevice device = ...;
if ( ! (device instanceof Sequencer) && ! (device instanceof Synthesizer)) {
  // we're now sure that device represents a MIDI port
  // ...
}

A MidiDevice includes a MidiDevice.Info object to provide manufacturer information and so on.

Nested Class Summary:
public static class  MidiDevice.Info  A MidiDevice.Info object contains assorted data about a {@link MidiDevice}, including its name, the company who created it, and descriptive text. 
Method from javax.sound.midi.MidiDevice Summary:
close,   getDeviceInfo,   getMaxReceivers,   getMaxTransmitters,   getMicrosecondPosition,   getReceiver,   getReceivers,   getTransmitter,   getTransmitters,   isOpen,   open
Method from javax.sound.midi.MidiDevice Detail:
 public  void close()
    Closes the device, indicating that the device should now release any system resources it is using.

    All Receiver and Transmitter instances open from this device are closed. This includes instances retrieved via MidiSystem.

 public Info getDeviceInfo()
    Obtains information about the device, including its Java class and Strings containing its name, vendor, and description.
 public int getMaxReceivers()
    Obtains the maximum number of MIDI IN connections available on this MIDI device for receiving MIDI data.
 public int getMaxTransmitters()
    Obtains the maximum number of MIDI OUT connections available on this MIDI device for transmitting MIDI data.
 public long getMicrosecondPosition()
    Obtains the current time-stamp of the device, in microseconds. If a device supports time-stamps, it should start counting at 0 when the device is opened and continue incrementing its time-stamp in microseconds until the device is closed. If it does not support time-stamps, it should always return -1.
 public Receiver getReceiver() throws MidiUnavailableException
    Obtains a MIDI IN receiver through which the MIDI device may receive MIDI data. The returned receiver must be closed when the application has finished using it.

    Usually the returned receiver implements the {@code MidiDeviceReceiver} interface.

    Obtaining a Receiver with this method does not open the device. To be able to use the device, it has to be opened explicitly by calling #open . Also, closing the Receiver does not close the device. It has to be closed explicitly by calling #close .

 public List<Receiver> getReceivers()
    Returns all currently active, non-closed receivers connected with this MidiDevice. A receiver can be removed from the device by closing it.

    Usually the returned receivers implement the {@code MidiDeviceReceiver} interface.

 public Transmitter getTransmitter() throws MidiUnavailableException
    Obtains a MIDI OUT connection from which the MIDI device will transmit MIDI data The returned transmitter must be closed when the application has finished using it.

    Usually the returned transmitter implements the {@code MidiDeviceTransmitter} interface.

    Obtaining a Transmitter with this method does not open the device. To be able to use the device, it has to be opened explicitly by calling #open . Also, closing the Transmitter does not close the device. It has to be closed explicitly by calling #close .

 public List<Transmitter> getTransmitters()
    Returns all currently active, non-closed transmitters connected with this MidiDevice. A transmitter can be removed from the device by closing it.

    Usually the returned transmitters implement the {@code MidiDeviceTransmitter} interface.

 public boolean isOpen()
    Reports whether the device is open.
 public  void open() throws MidiUnavailableException
    Opens the device, indicating that it should now acquire any system resources it requires and become operational.

    An application opening a device explicitly with this call has to close the device by calling #close . This is necessary to release system resources and allow applications to exit cleanly.

    Note that some devices, once closed, cannot be reopened. Attempts to reopen such a device will always result in a MidiUnavailableException.