HELP!Simple MIDI player based on Sequencer:how to set Volume?

Question

Hi,i'm Roberto,i'm student and i'm realizing a simple midi player in java (using java1.5 and javax.sound.midi package).....the program has a gui and it can just play midi files,and the player is a class based on a Sequencer object:so the method play() initializes a Sequence object from a file and this is given as parameter to the sequencer,so it runs with Sequencer.start();......
my BIG problem is:"how can change the volume when playng if the player's class is created as above?","how can i realize a method setVolume(int volume)?"......please help me!!!!!

Answer 1

Did the previous post fix the problem?
At what point should the synthesizer and sequencer be opened?
Can the volume be set at anytime during playback?
I have a similar problem and i tried both of these solutions and they did not work for me.
Heres my code:
    /** The midi sequencer */
    private Sequencer sequencer = null;
    /** The synthesizer (for volume control) */
    private Synthesizer synthesizer = null;
    /** The volume (as a percentage) */
    private double gain = 100.0d;
     * Default constructor.
     * @since 1.0
    public MidiPlayer() {
        try {
             // get the system sequencer
            this.sequencer = MidiSystem.getSequencer();
            // get the system synthesizer
            this.synthesizer = MidiSystem.getSynthesizer();
            // open the sequencer
            this.sequencer.open();
            // open the synthesizer
            this.synthesizer.open();
            // link the sequencer to the synthesizer
            this.sequencer.getTransmitter().setReceiver(this.synthesizer.getReceiver());
            // set this class to list for meta events
            // (end of track event in particular)
            this.sequencer.addMetaEventListener(this);
        } catch (MidiUnavailableException ex) {
            // TODO error handling
             ex.printStackTrace();
    public void play(Sequence sequence, boolean loop) {
        if (this.sequencer != null && sequence != null && this.sequencer.isOpen()) {
            try {
                 // give the sequencer the sequence
                 this.sequencer.setSequence(sequence);
                // start the sequencer
                 this.sequencer.start();
                //set the loop flag
                this.loop = loop;
            } catch (InvalidMidiDataException e) {
                e.printStackTrace();
                // TODO error handling
     public void setGain(double gain) {
          this.gain = gain;
         // change the percent value to a respective gain value
        int value = (int) (127 * (double) (this.gain / 100.0));
         // modify the volume of the sequence
        MidiChannel[] channels = this.synthesizer.getChannels();
        for(int i = 0; i < channels.length; i++) {
             channels.controlChange(7, value);
          MidiChannel[] channels = this.synthesizer.getChannels();
          for (int i = 0; i < channels.length; i++) {
               channels[i].controlChange(7, (int) (127 * (this.gain / 100.0)));