- All Superinterfaces:
- AutoCloseable,- MidiDevice
sequence is known as a sequencer. A MIDI sequence
 contains lists of time-stamped MIDI data, such as might be read from a
 standard MIDI file. Most sequencers also provide functions for creating and
 editing sequences.
 
 The Sequencer interface includes methods for the following basic MIDI
 sequencer operations:
 
- obtaining a sequence from MIDI file data
- starting and stopping playback
- moving to an arbitrary position in the sequence
- changing the tempo (speed) of playback
- synchronizing playback to an internal clock or to received MIDI messages
- controlling the timing of another device
Sequencer has access to:
 - editing the data by adding or deleting individual MIDI events or entire tracks
- muting or soloing individual tracks in the sequence
- notifying listener objects about any meta-events or control-change events encountered while playing back the sequence
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Nested Class SummaryNested ClassesModifier and TypeInterfaceDescriptionstatic classASyncModeobject represents one of the ways in which a MIDI sequencer's notion of time can be synchronized with a master or slave device.Nested classes/interfaces declared in interface javax.sound.midi.MidiDeviceMidiDevice.Info
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Field SummaryFieldsModifier and TypeFieldDescriptionstatic final intA value indicating that looping should continue indefinitely rather than complete after a specific number of loops.
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Method SummaryModifier and TypeMethodDescriptionint[]addControllerEventListener(ControllerEventListener listener, int[] controllers) Registers a controller event listener to receive notification whenever the sequencer processes a control-change event of the requested type or types.booleanaddMetaEventListener(MetaEventListener listener) Registers a meta-event listener to receive notification whenever a meta-event is encountered in the sequence and processed by the sequencer.intObtains the number of repetitions for playback.longObtains the end position of the loop, in MIDI ticks.longObtains the start position of the loop, in MIDI ticks.Obtains the current master synchronization mode for this sequencer.Obtains the set of master synchronization modes supported by this sequencer.longObtains the length of the current sequence, expressed in microseconds, or 0 if no sequence is set.longObtains the current position in the sequence, expressed in microseconds.Obtains the sequence on which the Sequencer is currently operating.Obtains the current slave synchronization mode for this sequencer.Obtains the set of slave synchronization modes supported by the sequencer.floatReturns the current tempo factor for the sequencer.floatObtains the current tempo, expressed in beats per minute.floatObtains the current tempo, expressed in microseconds per quarter note.longObtains the length of the current sequence, expressed in MIDI ticks, or 0 if no sequence is set.longObtains the current position in the sequence, expressed in MIDI ticks.booleangetTrackMute(int track) Obtains the current mute state for a track.booleangetTrackSolo(int track) Obtains the current solo state for a track.booleanIndicates whether the Sequencer is currently recording.booleanIndicates whether the Sequencer is currently running.voidrecordDisable(Track track) Disables recording to the specified track.voidrecordEnable(Track track, int channel) Prepares the specified track for recording events received on a particular channel.int[]removeControllerEventListener(ControllerEventListener listener, int[] controllers) Removes a controller event listener's interest in one or more types of controller event.voidremoveMetaEventListener(MetaEventListener listener) Removes the specified meta-event listener from this sequencer's list of registered listeners, if in fact the listener is registered.voidsetLoopCount(int count) Sets the number of repetitions of the loop for playback.voidsetLoopEndPoint(long tick) Sets the last MIDI tick that will be played in the loop.voidsetLoopStartPoint(long tick) Sets the first MIDI tick that will be played in the loop.voidSets the source of timing information used by this sequencer.voidsetMicrosecondPosition(long microseconds) Sets the current position in the sequence, expressed in microseconds.voidsetSequence(InputStream stream) Sets the current sequence on which the sequencer operates.voidsetSequence(Sequence sequence) Sets the current sequence on which the sequencer operates.voidSets the slave synchronization mode for the sequencer.voidsetTempoFactor(float factor) Scales the sequencer's actual playback tempo by the factor provided.voidsetTempoInBPM(float bpm) Sets the tempo in beats per minute.voidsetTempoInMPQ(float mpq) Sets the tempo in microseconds per quarter note.voidsetTickPosition(long tick) Sets the current sequencer position in MIDI ticks.voidsetTrackMute(int track, boolean mute) Sets the mute state for a track.voidsetTrackSolo(int track, boolean solo) Sets the solo state for a track.voidstart()Starts playback of the MIDI data in the currently loaded sequence.voidStarts recording and playback of MIDI data.voidstop()Stops recording, if active, and playback of the currently loaded sequence, if any.voidStops recording, if active.Methods declared in interface javax.sound.midi.MidiDeviceclose, getDeviceInfo, getMaxReceivers, getMaxTransmitters, getReceiver, getReceivers, getTransmitter, getTransmitters, isOpen, open
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Field Details- 
LOOP_CONTINUOUSLYstatic final int LOOP_CONTINUOUSLYA value indicating that looping should continue indefinitely rather than complete after a specific number of loops.- Since:
- 1.5
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Method Details- 
setSequenceSets the current sequence on which the sequencer operates.This method can be called even if the Sequenceris closed.- Parameters:
- sequence- the sequence to be loaded
- Throws:
- InvalidMidiDataException- if the sequence contains invalid MIDI data, or is not supported
 
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setSequenceSets the current sequence on which the sequencer operates. The stream must point to MIDI file data.This method can be called even if the Sequenceris closed.- Parameters:
- stream- stream containing MIDI file data
- Throws:
- IOException- if an I/O exception occurs during reading of the stream
- InvalidMidiDataException- if invalid data is encountered in the stream, or the stream is not supported
 
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getSequenceSequence getSequence()Obtains the sequence on which the Sequencer is currently operating.This method can be called even if the Sequenceris closed.- Returns:
- the current sequence, or nullif no sequence is currently set
 
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startvoid start()Starts playback of the MIDI data in the currently loaded sequence. Playback will begin from the current position. If the playback position reaches the loop end point, and the loop count is greater than 0, playback will resume at the loop start point for the number of repetitions set withsetLoopCount. After that, or if the loop count is 0, playback will continue to play to the end of the sequence.The implementation ensures that the synthesizer is brought to a consistent state when jumping to the loop start point by sending appropriate controllers, pitch bend, and program change events. - Throws:
- IllegalStateException- if the- Sequenceris closed
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stopvoid stop()Stops recording, if active, and playback of the currently loaded sequence, if any.- Throws:
- IllegalStateException- if the- Sequenceris closed
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isRunningboolean isRunning()Indicates whether the Sequencer is currently running. The default isfalse. The Sequencer starts running when eitherstart()orstartRecording()is called.isRunningthen returnstrueuntil playback of the sequence completes orstop()is called.- Returns:
- trueif the Sequencer is running, otherwise- false
 
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startRecordingvoid startRecording()Starts recording and playback of MIDI data. Data is recorded to all enabled tracks, on the channel(s) for which they were enabled. Recording begins at the current position of the sequencer. Any events already in the track are overwritten for the duration of the recording session. Events from the currently loaded sequence, if any, are delivered to the sequencer's transmitter(s) along with messages received during recording.Note that tracks are not by default enabled for recording. In order to record MIDI data, at least one track must be specifically enabled for recording. - Throws:
- IllegalStateException- if the- Sequenceris closed
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stopRecordingvoid stopRecording()Stops recording, if active. Playback of the current sequence continues.- Throws:
- IllegalStateException- if the- Sequenceris closed
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isRecordingboolean isRecording()Indicates whether the Sequencer is currently recording. The default isfalse. The Sequencer begins recording whenstartRecording()is called, and then returnstrueuntilstop()orstopRecording()is called.- Returns:
- trueif the Sequencer is recording, otherwise- false
 
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recordEnablePrepares the specified track for recording events received on a particular channel. Once enabled, a track will receive events when recording is active.- Parameters:
- track- the track to which events will be recorded
- channel- the channel on which events will be received. If -1 is specified for the channel value, the track will receive data from all channels.
- Throws:
- IllegalArgumentException- thrown if the track is not part of the current sequence
 
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recordDisableDisables recording to the specified track. Events will no longer be recorded into this track.- Parameters:
- track- the track to disable for recording, or- nullto disable recording for all tracks
 
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getTempoInBPMfloat getTempoInBPM()Obtains the current tempo, expressed in beats per minute. The actual tempo of playback is the product of the returned value and the tempo factor.- Returns:
- the current tempo in beats per minute
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setTempoInBPMvoid setTempoInBPM(float bpm) Sets the tempo in beats per minute. The actual tempo of playback is the product of the specified value and the tempo factor.- Parameters:
- bpm- desired new tempo in beats per minute
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getTempoInMPQfloat getTempoInMPQ()Obtains the current tempo, expressed in microseconds per quarter note. The actual tempo of playback is the product of the returned value and the tempo factor.- Returns:
- the current tempo in microseconds per quarter note
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setTempoInMPQvoid setTempoInMPQ(float mpq) Sets the tempo in microseconds per quarter note. The actual tempo of playback is the product of the specified value and the tempo factor.- Parameters:
- mpq- desired new tempo in microseconds per quarter note
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setTempoFactorvoid setTempoFactor(float factor) Scales the sequencer's actual playback tempo by the factor provided. The default is 1.0. A value of 1.0 represents the natural rate (the tempo specified in the sequence), 2.0 means twice as fast, etc. The tempo factor does not affect the values returned bygetTempoInMPQ()andgetTempoInBPM(). Those values indicate the tempo prior to scaling.Note that the tempo factor cannot be adjusted when external synchronization is used. In that situation, setTempoFactoralways sets the tempo factor to 1.0.- Parameters:
- factor- the requested tempo scalar
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getTempoFactorfloat getTempoFactor()Returns the current tempo factor for the sequencer. The default is 1.0.- Returns:
- tempo factor
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getTickLengthlong getTickLength()Obtains the length of the current sequence, expressed in MIDI ticks, or 0 if no sequence is set.- Returns:
- length of the sequence in ticks
 
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getTickPositionlong getTickPosition()Obtains the current position in the sequence, expressed in MIDI ticks. (The duration of a tick in seconds is determined both by the tempo and by the timing resolution stored in theSequence.)- Returns:
- current tick
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setTickPositionvoid setTickPosition(long tick) Sets the current sequencer position in MIDI ticks.- Parameters:
- tick- the desired tick position
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getMicrosecondLengthlong getMicrosecondLength()Obtains the length of the current sequence, expressed in microseconds, or 0 if no sequence is set.- Returns:
- length of the sequence in microseconds
 
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getMicrosecondPositionlong getMicrosecondPosition()Obtains the current position in the sequence, expressed in microseconds.- Specified by:
- getMicrosecondPositionin interface- MidiDevice
- Returns:
- the current position in microseconds
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setMicrosecondPositionvoid setMicrosecondPosition(long microseconds) Sets the current position in the sequence, expressed in microseconds.- Parameters:
- microseconds- desired position in microseconds
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setMasterSyncModeSets the source of timing information used by this sequencer. The sequencer synchronizes to the master, which is the internal clock, MIDI clock, or MIDI time code, depending on the value ofsync. Thesyncargument must be one of the supported modes, as returned bygetMasterSyncModes().- Parameters:
- sync- the desired master synchronization mode
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getMasterSyncModeSequencer.SyncMode getMasterSyncMode()Obtains the current master synchronization mode for this sequencer.- Returns:
- the current master synchronization mode
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getMasterSyncModesSequencer.SyncMode[] getMasterSyncModes()Obtains the set of master synchronization modes supported by this sequencer.- Returns:
- the available master synchronization modes
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setSlaveSyncModeSets the slave synchronization mode for the sequencer. This indicates the type of timing information sent by the sequencer to its receiver. Thesyncargument must be one of the supported modes, as returned bygetSlaveSyncModes().- Parameters:
- sync- the desired slave synchronization mode
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getSlaveSyncModeSequencer.SyncMode getSlaveSyncMode()Obtains the current slave synchronization mode for this sequencer.- Returns:
- the current slave synchronization mode
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getSlaveSyncModesSequencer.SyncMode[] getSlaveSyncModes()Obtains the set of slave synchronization modes supported by the sequencer.- Returns:
- the available slave synchronization modes
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setTrackMutevoid setTrackMute(int track, boolean mute) Sets the mute state for a track. This method may fail for a number of reasons. For example, the track number specified may not be valid for the current sequence, or the sequencer may not support this functionality. An application which needs to verify whether this operation succeeded should follow this call with a call togetTrackMute(int).- Parameters:
- track- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.
- mute- the new mute state for the track.- trueimplies the track should be muted,- falseimplies the track should be unmuted.
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getTrackMuteboolean getTrackMute(int track) Obtains the current mute state for a track. The default mute state for all tracks which have not been muted is false. In any case where the specified track has not been muted, this method should return false. This applies if the sequencer does not support muting of tracks, and if the specified track index is not valid.- Parameters:
- track- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.
- Returns:
- trueif muted,- falseif not
 
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setTrackSolovoid setTrackSolo(int track, boolean solo) Sets the solo state for a track. Ifsoloistrueonly this track and other solo'd tracks will sound. Ifsoloisfalsethen only other solo'd tracks will sound, unless no tracks are solo'd in which case all un-muted tracks will sound.This method may fail for a number of reasons. For example, the track number specified may not be valid for the current sequence, or the sequencer may not support this functionality. An application which needs to verify whether this operation succeeded should follow this call with a call to getTrackSolo(int).- Parameters:
- track- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.
- solo- the new solo state for the track.- trueimplies the track should be solo'd,- falseimplies the track should not be solo'd.
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getTrackSoloboolean getTrackSolo(int track) Obtains the current solo state for a track. The default mute state for all tracks which have not been solo'd is false. In any case where the specified track has not been solo'd, this method should return false. This applies if the sequencer does not support soloing of tracks, and if the specified track index is not valid.- Parameters:
- track- the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1.
- Returns:
- trueif solo'd,- falseif not
 
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addMetaEventListenerRegisters a meta-event listener to receive notification whenever a meta-event is encountered in the sequence and processed by the sequencer. This method can fail if, for instance, this class of sequencer does not support meta-event notification.- Parameters:
- listener- listener to add
- Returns:
- trueif the listener was successfully added, otherwise- false
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removeMetaEventListenerRemoves the specified meta-event listener from this sequencer's list of registered listeners, if in fact the listener is registered.- Parameters:
- listener- the meta-event listener to remove
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addControllerEventListenerRegisters a controller event listener to receive notification whenever the sequencer processes a control-change event of the requested type or types. The types are specified by thecontrollersargument, which should contain an array of MIDI controller numbers. (Each number should be between 0 and 127, inclusive. See the MIDI 1.0 Specification for the numbers that correspond to various types of controllers.)The returned array contains the MIDI controller numbers for which the listener will now receive events. Some sequencers might not support controller event notification, in which case the array has a length of 0. Other sequencers might support notification for some controllers but not all. This method may be invoked repeatedly. Each time, the returned array indicates all the controllers that the listener will be notified about, not only the controllers requested in that particular invocation. - Parameters:
- listener- the controller event listener to add to the list of registered listeners
- controllers- the MIDI controller numbers for which change notification is requested
- Returns:
- the numbers of all the MIDI controllers whose changes will now be reported to the specified listener
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removeControllerEventListenerRemoves a controller event listener's interest in one or more types of controller event. Thecontrollersargument is an array of MIDI numbers corresponding to the controllers for which the listener should no longer receive change notifications. To completely remove this listener from the list of registered listeners, pass innullforcontrollers. The returned array contains the MIDI controller numbers for which the listener will now receive events. The array has a length of 0 if the listener will not receive change notifications for any controllers.- Parameters:
- listener- old listener
- controllers- the MIDI controller numbers for which change notification should be cancelled, or- nullto cancel for all controllers
- Returns:
- the numbers of all the MIDI controllers whose changes will now be reported to the specified listener
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setLoopStartPointvoid setLoopStartPoint(long tick) Sets the first MIDI tick that will be played in the loop. If the loop count is greater than 0, playback will jump to this point when reaching the loop end point.A value of 0 for the starting point means the beginning of the loaded sequence. The starting point must be lower than or equal to the ending point, and it must fall within the size of the loaded sequence. A sequencer's loop start point defaults to start of the sequence. - Parameters:
- tick- the loop's starting position, in MIDI ticks (zero-based)
- Throws:
- IllegalArgumentException- if the requested loop start point cannot be set, usually because it falls outside the sequence's duration or because the start point is after the end point
- Since:
- 1.5
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getLoopStartPointlong getLoopStartPoint()Obtains the start position of the loop, in MIDI ticks.- Returns:
- the start position of the loop, in MIDI ticks (zero-based)
- Since:
- 1.5
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setLoopEndPointvoid setLoopEndPoint(long tick) Sets the last MIDI tick that will be played in the loop. If the loop count is 0, the loop end point has no effect and playback continues to play when reaching the loop end point.A value of -1 for the ending point indicates the last tick of the sequence. Otherwise, the ending point must be greater than or equal to the starting point, and it must fall within the size of the loaded sequence. A sequencer's loop end point defaults to -1, meaning the end of the sequence. - Parameters:
- tick- the loop's ending position, in MIDI ticks (zero-based), or -1 to indicate the final tick
- Throws:
- IllegalArgumentException- if the requested loop point cannot be set, usually because it falls outside the sequence's duration or because the ending point is before the starting point
- Since:
- 1.5
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getLoopEndPointlong getLoopEndPoint()Obtains the end position of the loop, in MIDI ticks.- Returns:
- the end position of the loop, in MIDI ticks (zero-based), or -1 to indicate the end of the sequence
- Since:
- 1.5
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setLoopCountvoid setLoopCount(int count) Sets the number of repetitions of the loop for playback. When the playback position reaches the loop end point, it will loop back to the loop start pointcounttimes, after which playback will continue to play to the end of the sequence.If the current position when this method is invoked is greater than the loop end point, playback continues to the end of the sequence without looping, unless the loop end point is changed subsequently. A countvalue of 0 disables looping: playback will continue at the loop end point, and it will not loop back to the loop start point. This is a sequencer's default.If playback is stopped during looping, the current loop status is cleared; subsequent start requests are not affected by an interrupted loop operation. - Parameters:
- count- the number of times playback should loop back from the loop's end position to the loop's start position, or- LOOP_CONTINUOUSLYto indicate that looping should continue until interrupted
- Throws:
- IllegalArgumentException- if- countis negative and not equal to- LOOP_CONTINUOUSLY
- Since:
- 1.5
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getLoopCountint getLoopCount()Obtains the number of repetitions for playback.- Returns:
- the number of loops after which playback plays to the end of the sequence
- Since:
- 1.5
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