[help] my beatbox prgramming

[matvey]

I run it on Eclipse but when i press button "play" , it shows error. Can you try to run it to help me? Thanks for your care!

import java.awt.*;
import javax.swing.*;
import javax.sound.midi.*;
import java.util.*;
import java.awt.event.*;

public class BeatBox implements MetaEventListener {
	
	JPanel mainPanel;
	ArrayList checkboxList;
	int bpm;
	Sequencer sequencer;
	Sequence sequence;
	Track track;
	JFrame theFrame;
	
	String[] instrumentNames= { "Bass Drum","Closed Hi-hat","Open Hi-hat","Acoustic Snare","Crash Cymbal"
			,"Hand Clap","High Tom","Hi Bongo","Macaras","Whistle","Low Conga","Cowbell","Vibraslap"
			,"Low-mid Tom","High Agogo","Open Hi Conga"};
	
	int[] instruments= {35,42,46,38,49,50,60,70,72,64,56,58,47,67,63};
	
	public static void main(String[] args) {
		
		new BeatBox().buildGUI();

	}
	
	public void buildGUI()
	{
		theFrame=new JFrame("Cyber BeatBox");
		BorderLayout layout=new BorderLayout();
		JPanel background=new JPanel(layout);
		
		background.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
		checkboxList=new ArrayList();
		Box buttonBox=new Box(BoxLayout.Y_AXIS);
		
		JButton start=new JButton("start");
		start.addActionListener(new MyStartListener());
		buttonBox.add(start);
		
		JButton stop=new JButton("stop");
		stop.addActionListener(new MyStopListener());
		buttonBox.add(stop);
		
		JButton upTempo=new JButton("upTempo");
		upTempo.addActionListener(new MyUpTempoListener());
		buttonBox.add(upTempo);
		
		JButton downTempo=new JButton("downTempo");
		downTempo.addActionListener(new MyDownTempoListener());
		buttonBox.add(downTempo);
		
		Box nameBox=new Box(BoxLayout.Y_AXIS);
		
		for(int i=0;i<16;i++)
		{
			nameBox.add(new Label(instrumentNames[i]));
		}
		
		background.add(BorderLayout.EAST,buttonBox);
		background.add(BorderLayout.WEST,nameBox);
		
		theFrame.getContentPane().add(background);
		
		GridLayout grid=new GridLayout(16,16);
		
		grid.setVgap(1);
		grid.setVgap(2);
		
		mainPanel=new JPanel(grid);
		
		background.add(BorderLayout.CENTER,mainPanel);
		
		for(int i=0;i<256;i++)
		{
			JCheckBox c=new JCheckBox();
			c.setSelected(false);
			checkboxList.add(c);
			
			mainPanel.add(c);
			
		}
		
		setUpMidi();
		
		theFrame.setBounds(50,50,300,300);
		
		theFrame.pack();
		theFrame.setVisible(true);
				
			
	}
	
	public void setUpMidi()
	{
		try{
			sequencer =MidiSystem.getSequencer();
			sequencer.open();
			
			sequencer.addMetaEventListener(this);
			sequence=new Sequence(Sequence.PPQ,4);
			track=sequence.createTrack();
			sequencer.setTempoInBPM(bpm);
			
			
		}
		
		catch(Exception e)
		{
			e.printStackTrace();
		}
	}
	
	public void buildTrackAndStart()
	{
		int[] trackList=null;
		int j,key;
		
		sequence.deleteTrack(track);
		track =sequence.createTrack();
		
		for(int i=0;i<16;i++)
		{
			trackList=new int[16];
			key=instruments[i];
			
			for(j=0;j<16;j++)
			{
				JCheckBox jc=(JCheckBox)checkboxList.get(j+(16*i));
				if(jc.isSelected())
				{
					trackList[j]=key;
					
				}
				else
				{
					trackList[j]=0;
				}
			}
			
			makeTracks(trackList);
						
		}
		
		track.add(makeEvent(192,9,1,0,15));
		try
		{
			sequencer.setSequence(sequence);
			sequencer.start();
			sequencer.setTempoInBPM(bpm);
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		
		
	}
	
	public class MyStartListener implements ActionListener
	{
		public void actionPerformed(ActionEvent a)
		{
			buildTrackAndStart();
		}
	}
	
	public class MyStopListener implements ActionListener
	{
		public void actionPerformed(ActionEvent a)
		{
			sequencer.stop();
		}
	}
	
	public class MyUpTempoListener implements ActionListener
	{
		public void actionPerformed(ActionEvent a)
		{
			bpm+=3;
		}
	}
	
	public class MyDownTempoListener implements ActionListener
	{
		public void actionPerformed(ActionEvent a)
		{
			bpm-=3;
		}
	}
	
	public void makeTracks(int[] list)
	{
		int key;
		for(int i=0;i<16;i++)
		{
			 key=list[i];
			
			if(key!=0)
			{
				track.add(makeEvent(144,9,key,100,i));
				track.add(makeEvent(128,9,key,100,i+1));
				
			}
		}
	}
	
	 public static MidiEvent makeEvent(int comd,int chan,int one,int two,int tick)
	 {
		 MidiEvent event=null;
		 
		 try{
			 ShortMessage a=new ShortMessage();
			 a.setMessage(comd, chan, one, two);
			 event=new MidiEvent(a,tick);
		
		 }
		 catch(Exception e){
			 e.printStackTrace();
			 
		 }
		 return event;
	 }
	 
	 public void meta(MetaMessage message)
	 {
		 if(message.getType()==47)
		 {
			 sequencer.start();
			 sequencer.setTempoInBPM(bpm);
		 }
	 }				
		
}

[r035198x]

Why don't you post the error that you got?

[matvey]

this is it.i'm sorry .

at java.awt.EventDispatchThread.pumpEventsForFilter(U nknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)