MidiMessage is the base class for MIDI messages. They include not
only the standard MIDI messages that a synthesizer can respond to, but also
"meta-events" that can be used by sequencer programs. There are meta-events
for such information as lyrics, copyrights, tempo indications, time and key
signatures, markers, etc. For more information, see the Standard MIDI Files
1.0 specification, which is part of the Complete MIDI 1.0 Detailed
Specification published by the MIDI Manufacturer's Association
(http://www.midi.org).
The base MidiMessage class provides access to three types of
information about a MIDI message:
MidiMessage includes methods to get, but not set, these values.
Setting them is a subclass responsibility.
The MIDI standard expresses MIDI data in bytes.
However, because Java uses signed bytes, the Java Sound API uses
integers instead of bytes when expressing MIDI data. For example, the
getStatus() method of MidiMessage returns MIDI status bytes
as integers. If you are processing MIDI data that originated outside Java
Sound and now is encoded as signed bytes, the bytes can be converted to
integers using this conversion:
int i = (int)(byte & 0xFF)
If you simply need to pass a known MIDI byte value as a method parameter, it
can be expressed directly as an integer, using (for example) decimal or
hexadecimal notation. For instance, to pass the "active sensing" status byte
as the first argument to ShortMessage's
setMessage(int) method, you can express
it as 254 or 0xFE.
Track, Sequence, Receiver
| Modifier and Type | Field and Description |
|---|---|
| protected byte[] | data
The MIDI message data. |
| protected int | length
The number of bytes in the MIDI message, including the status byte and any data bytes. |
| Access | Constructor and Description |
|---|---|
| protected | MidiMessage(byte[]
an array of bytes containing the complete message. The
message data may be changed using the data)setMessage method.Constructs a new |
| Modifier and Type | Method and Description |
|---|---|
| public abstract Object | Returns: a clone of this instanceOverrides java. Creates a new object of the same class and with the same contents as this object. |
| public int | Returns: the length of the message in bytesObtains the total length of the MIDI message in bytes. |
| public byte[] | Returns: the byte array containing the completeMidiMessage dataObtains the MIDI message data. |
| public int | Returns: the integer representation of this event's status byteObtains the status byte for the MIDI message. |
| protected void | setMessage(byte[]
the data bytes in the MIDI message data, int the number of bytes in the data byte array length)Sets the data for the MIDI message. |
| data | back to summary |
|---|---|
| protected byte[] data The MIDI message data. The first byte is the status byte for the message; subsequent bytes up to the length of the message are data bytes for this message.
| |
| length | back to summary |
|---|---|
| protected int length The number of bytes in the MIDI message, including the status byte and any data bytes.
| |
| MidiMessage | back to summary |
|---|---|
| protected MidiMessage(byte[] data) Constructs a new
| |
| clone | back to summary |
|---|---|
| public abstract Object clone() Overrides java. Creates a new object of the same class and with the same contents as this object. | |
| getLength | back to summary |
|---|---|
| public int getLength() Obtains the total length of the MIDI message in bytes. A MIDI message consists of one status byte and zero or more data bytes. The return value ranges from 1 for system real-time messages, to 2 or 3 for channel messages, to any value for meta and system exclusive messages.
| |
| getMessage | back to summary |
|---|---|
| public byte[] getMessage() Obtains the MIDI message data. The first byte of the returned byte array
is the status byte of the message. Any subsequent bytes up to the length
of the message are data bytes. The byte array may have a length which is
greater than that of the actual message; the total length of the message
in bytes is reported by the
| |
| getStatus | back to summary |
|---|---|
| public int getStatus() Obtains the status byte for the MIDI message. The status "byte" is
represented as an integer; see the
discussion in the
| |
| setMessage | back to summary |
|---|---|
| protected void setMessage(byte[] data, int length) throws InvalidMidiDataException Sets the data for the MIDI message. This protected method is called by concrete subclasses, which should ensure that the data array specifies a complete, valid MIDI message.
| |