MidiDevice JDK 1.6)

Description

public interface MidiDevice

MidiDevice is the base interface for all MIDI devices.

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 MidiDevice.open(), explicit closing is done by calling MidiDevice.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 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:

After an explicit open (either before or after implicit opens), the device will not be closed by implicit closing. The only way to close an explicitly opened device is an explicit close.
An explicit close always closes the device, even if it also has been opened implicitly. A subsequent implicit close has no further effect.

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.

See also: Synthesizer Sequencer Receiver Transmitter

Methods

Hide/Show inherited methods

public void close ()

Closes the device, indicating that the device should now release any system resources it is using.

public Info getDeviceInfo ()

Obtains information about the device, including its Java class and Strings containing its name, vendor, and description.

Obtains information about the device, including its Java class and
Strings containing its name, vendor, and description.
Returns: device info

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.

public Receiver getReceiver () throws MidiUnavailableException

Obtains a MIDI IN receiver through which the MIDI device may receive MIDI data.

public List<Receiver> getReceivers ()

Returns all currently active, non-closed receivers connected with this MidiDevice.

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.

public List<Transmitter> getTransmitters ()

Returns all currently active, non-closed transmitters connected with this MidiDevice.

public boolean isOpen ()

Reports whether the device is open.

Reports whether the device is open.
Returns: true if the device is open, otherwise false
See Also: MidiDevice.open(), MidiDevice.close(),

public void open () throws MidiUnavailableException

Opens the device, indicating that it should now acquire any system resources it requires and become operational.