Android APIs
public final class

MidiDevice

extends Object
implements Closeable
java.lang.Object
   ↳ android.media.midi.MidiDevice

Class Overview

This class is used for sending and receiving data to and from a MIDI device Instances of this class are created by openDevice(MidiDeviceInfo, MidiManager.OnDeviceOpenedListener, Handler).

Summary

Nested Classes
class MidiDevice.MidiConnection This class represents a connection between the output port of one device and the input port of another. 
Public Methods
void close()
Closes the object and release any system resources it holds.
MidiDevice.MidiConnection connectPorts(MidiInputPort inputPort, int outputPortNumber)
Connects the supplied MidiInputPort to the output port of this device with the specified port number.
MidiDeviceInfo getInfo()
Returns a MidiDeviceInfo object, which describes this device.
MidiInputPort openInputPort(int portNumber)
Called to open a MidiInputPort for the specified port number.
MidiOutputPort openOutputPort(int portNumber)
Called to open a MidiOutputPort for the specified port number.
String toString()
Returns a string containing a concise, human-readable description of this object.
Protected Methods
void finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.io.Closeable
From interface java.lang.AutoCloseable

Public Methods

public void close ()

Added in API level 23

Closes the object and release any system resources it holds.

Although only the first call has any effect, it is safe to call close multiple times on the same object. This is more lenient than the overridden AutoCloseable.close(), which may be called at most once.

Throws
IOException

public MidiDevice.MidiConnection connectPorts (MidiInputPort inputPort, int outputPortNumber)

Added in API level 23

Connects the supplied MidiInputPort to the output port of this device with the specified port number. Once the connection is made, the MidiInput port instance can no longer receive data via its onSend(byte[], int, int, long) method. This method returns a MidiDevice.MidiConnection object, which can be used to close the connection.

Parameters
inputPort the inputPort to connect
outputPortNumber the port number of the output port to connect inputPort to.
Returns

public MidiDeviceInfo getInfo ()

Added in API level 23

Returns a MidiDeviceInfo object, which describes this device.

Returns

public MidiInputPort openInputPort (int portNumber)

Added in API level 23

Called to open a MidiInputPort for the specified port number. An input port can only be used by one sender at a time. Opening an input port will fail if another application has already opened it for use. A MidiDeviceStatus can be used to determine if an input port is already open.

Parameters
portNumber the number of the input port to open
Returns
  • the MidiInputPort if the open is successful, or null in case of failure.

public MidiOutputPort openOutputPort (int portNumber)

Added in API level 23

Called to open a MidiOutputPort for the specified port number. An output port may be opened by multiple applications.

Parameters
portNumber the number of the output port to open
Returns
  • the MidiOutputPort if the open is successful, or null in case of failure.

public String toString ()

Added in API level 23

Returns a string containing a concise, human-readable description of this object. Subclasses are encouraged to override this method and provide an implementation that takes into account the object's type and data. The default implementation is equivalent to the following expression:

   getClass().getName() + '@' + Integer.toHexString(hashCode())

See Writing a useful toString method if you intend implementing your own toString method.

Returns
  • a printable representation of this object.

Protected Methods

protected void finalize ()

Added in API level 23

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable