Module java.desktop
Package 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 Description
    static int META
    Status byte for MetaMessage (0xFF, or 255), which is used in MIDI files.

    Fields declared in class javax.sound.midi.MidiMessage

    data, length

  • Constructor Summary

    Constructors 
    Modifier Constructor 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

    Modifier and Type Method 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 declared in class javax.sound.midi.MidiMessage

    getLength, getMessage, getStatus, setMessage

    Methods declared in class java.lang.Object

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

  • Field Details

  • Constructor Details

    • 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 Details

    • 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