MetaMessage (Java Platform SE 8 )
Keywords: javax.sound.midi.MetaMessage class
Date: 2015-11-19

javax.sound.midi

## Class MetaMessage

- java.lang.Object
- - javax.sound.midi.MidiMessage
  - - javax.sound.midi.MetaMessage

- All Implemented Interfaces:
    Cloneable

      public class MetaMessage
      extends MidiMessage

  A `MetaMessage` is a ``MidiMessage`` that is not meaningful to synthesizers, but that can be stored in a MIDI file and interpreted by a sequencer program. (See the discussion in the `MidiMessage` class description.) The Standard MIDI Files specification defines various types of meta-events, such as sequence number, lyric, cue point, and set tempo. There are also 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).

  When data is being transported using MIDI wire protocol, a ``ShortMessage`` with the status value `0xFF` represents a system reset message. In MIDI files, this same status value denotes a `MetaMessage`. The types of meta-message are distinguished from each other by the first byte that follows the status byte `0xFF`. The subsequent bytes are data bytes. As with system exclusive messages, there are an arbitrary number of data bytes, depending on the type of `MetaMessage`.

  See Also:
    `MetaEventListener`

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `META` Status byte for `MetaMessage` (0xFF, or 255), which is used in MIDI files.

    - ### Fields inherited from class javax.sound.midi.MidiMessage

      `data, length`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `` | `MetaMessage()` Constructs a new `MetaMessage`.
    `protected` | `MetaMessage(byte[] data)` Constructs a new `MetaMessage`.
    `` | `MetaMessage(int type, byte[] data, int length)` Constructs a new `MetaMessage` and sets the message parameters.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `Object` | `clone()` Creates a new object of the same class and with the same contents as this object.
    `byte[]` | `getData()` Obtains a copy of the data for the meta message.
    `int` | `getType()` Obtains the type of the `MetaMessage`.
    `void` | `setMessage(int type, byte[] data, int length)` Sets the message parameters for a `MetaMessage`.

    - ### Methods inherited from class javax.sound.midi.MidiMessage

      `getLength, getMessage, getStatus, setMessage`

    - ### Methods inherited from class java.lang.Object

      `equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### META

          public static final int META

      Status byte for `MetaMessage` (0xFF, or 255), which is used in MIDI files. It has the same value as SYSTEM_RESET, which is used in the real-time "MIDI wire" protocol.
      See Also:
        `MidiMessage.getStatus()`, Constant Field Values

  - ### Constructor Detail

    - #### MetaMessage

          public MetaMessage()

      Constructs a new `MetaMessage`. The contents of the message are not set here; use `setMessage` to set them subsequently.

    - #### MetaMessage

          public MetaMessage(int type,
                             byte[] data,
                             int length)
                      throws InvalidMidiDataException

      Constructs a new `MetaMessage` and sets the message parameters. The contents of the message can be changed by using the `setMessage` method.
      Parameters:
        `type` - meta-message type (must be less than 128)
        `data` - the data bytes in the MIDI message
        `length` - an amount of bytes in the `data` byte array; it should be non-negative and less than or equal to `data.length`
      Throws:
        `InvalidMidiDataException` - if the parameter values do not specify a valid MIDI meta message
      Since:
        1.7
      See Also:
        `setMessage(int, byte[], int)`, `getType()`, `getData()`

    - #### MetaMessage

          protected MetaMessage(byte[] data)

      Constructs a new `MetaMessage`.
      Parameters:
        `data` - an array of bytes containing the complete message. The message data may be changed using the `setMessage` method.
      See Also:
        `setMessage(int, byte[], int)`

  - ### Method Detail

    - #### setMessage

          public void setMessage(int type,
                                 byte[] data,
                                 int length)
                          throws InvalidMidiDataException

      Sets the message parameters for a `MetaMessage`. Since only one status byte value, `0xFF`, is allowed for meta-messages, it does not need to be specified here. Calls to ``getStatus`` return `0xFF` for all meta-messages.

      The `type` argument should be a valid value for the byte that follows the status byte in the `MetaMessage`. The `data` argument should contain all the subsequent bytes of the `MetaMessage`. In other words, the byte that specifies the type of `MetaMessage` is not considered a data byte.

      Parameters:
        `type` - meta-message type (must be less than 128)
        `data` - the data bytes in the MIDI message
        `length` - the number of bytes in the `data` byte array
      Throws:
        `InvalidMidiDataException` - if the parameter values do not specify a valid MIDI meta message

    - #### getType

          public int getType()

      Obtains the type of the `MetaMessage`.
      Returns:
        an integer representing the `MetaMessage` type

    - #### getData

          public byte[] getData()

      Obtains a copy of the data for the meta message. The returned array of bytes does not include the status byte or the message length data. The length of the data for the meta message is the length of the array. Note that the length of the entire message includes the status byte and the meta message type byte, and therefore may be longer than the returned array.
      Returns:
        array containing the meta message data.
      See Also:
        `MidiMessage.getLength()`

    - #### clone

          public Object clone()

      Creates a new object of the same class and with the same contents as this object.
      Specified by:
        `clone` in class `MidiMessage`
      Returns:
        a clone of this instance
      See Also:
        `Cloneable`

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