JSlider is not working.

I am going to plot a 2d, a combox and a JSlider.but JSlider is not working.
Please help me.
thanks

import java.io.*;
 
import java.awt.Font;
import java.awt.Color;
import java.awt.Graphics;
 
import java.awt.geom.*;
 
import java.awt.*;
import java.awt.BorderLayout;
import javax.swing.*;
 
import java.util.Hashtable;
import java.awt.event.*;
import javax.swing.event.*;
import java.applet.Applet;
public class TestLayout extends JApplet
{
private Drawing drawing;
       
        private JComboBox comb;
        private JComboBox alfa;
        private JSlider dJSlider;
private Container panel;
        private String af[] = {"Paint","No Paint"};
        private String e[] = {"One","Two"};
        private GridBagLayout layout;
        private GridBagConstraints gbc;
        
public void init()
{
panel = getContentPane();
                drawing = new Drawing();
                JPanel p2 = new JPanel();
                p2.add(drawing,BorderLayout.CENTER);
                p2.add(new getSlider(),BorderLayout.NORTH);
                p2.add(new getComboPanel(),BorderLayout.EAST);
                panel.add(p2,"Center");
}
 
        class  getComboPanel extends JPanel {
                public getComboPanel(){
                comb = new JComboBox(e);
                layout = new GridBagLayout();
                           
                setLayout(layout);
                gbc = new GridBagConstraints();
                addComponent(this,comb,0,0,1,1,GridBagConstraints.NONE, GridBagConstraints.CENTER);
                comb.setEditable(false);
                comb.setForeground (Color.BLUE);
                comb.setBackground (Color.GREEN);
 
                comb.setAlignmentX(Component.LEFT_ALIGNMENT);
               
                alfa = new JComboBox(af);
                gbc.weightx = 100;
                gbc.weighty = 0;
                addComponent(this,alfa,1,0,20000,1,GridBagConstraints.NONE, GridBagConstraints.CENTER);
                alfa.setEditable(false);
                alfa.setForeground(Color.BLUE);
                alfa.setBackground(Color.GREEN);
                alfa.setAlignmentX(Component.LEFT_ALIGNMENT);
                
                add(comb);
                add(alfa);
 } 
                
        
         private void addComponent(Container container, Component component,
                 int row, int column, int width, int height, int fill, int anchor)
         {
             gbc.gridx = column;
             gbc.gridy = row;
             gbc.gridwidth = width;
             gbc.gridheight = height;
             gbc.fill = fill;
             gbc.anchor = anchor;
             layout.setConstraints(component,gbc);
             container.add(component);
         }
}
        
          class  getSlider extends JPanel {
            public getSlider(){
                int min = 1, max = 16, inc = 5;
                dJSlider = new JSlider(min, max, 6);
                dJSlider.setMajorTickSpacing(5);
                dJSlider.setMinorTickSpacing(1);
                dJSlider.setSnapToTicks(true);
                dJSlider.setLabelTable(getLabelTable(min, max, inc));
                dJSlider.setPaintTicks(true);
                dJSlider.setPaintLabels(true);
               
            }   
   
        private Hashtable getLabelTable(int min, int max, int inc) {
        Hashtable<Integer, JLabel> table = new Hashtable<Integer, JLabel>();
        for(int j = min; j <= max; j+=inc) {
            String s = String.format("%.1f", (j+4)/10.0);
            table.put(Integer.valueOf(j), new JLabel(s));
        }
        return table;
    }
}
 
 class Drawing extends JPanel 
{
       public void paintComponent(Graphics g)
    {
            super.paintComponent( g ); // call superclass's paint method
            this.setBackground( Color.WHITE );
            Graphics2D g2d = (Graphics2D)g; 
            g2d.draw3DRect(3,100,90,55,true);
 }
   // end method paintComponent
 }
       public static void main(String[] args)
            {
            JFrame appletFrame = new JFrame("My Applet");
            Applet theApplet = new TestLayout();
            appletFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            appletFrame.setSize(800,800);
            appletFrame.add(theApplet,"Center");
            theApplet.init();
            appletFrame.setVisible(true);
            }
}

I don't see any code that "listens" for when the slider is changed and does something when that happens.

See Java Tutorial - How to Use Sliders and Java Tutorial - How to Write a Change Listener.

sorry,please see my new code.

import java.io.*;
import java.util.List;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.ListIterator;
import java.util.Scanner;
 
import java.awt.Font;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.BasicStroke;
import java.awt.GradientPaint;
import java.awt.geom.GeneralPath;
import java.awt.AlphaComposite;
import java.awt.Composite;
import java.awt.geom.*;
 
import java.awt.*;
import java.awt.BorderLayout;
import javax.swing.*;
 
import java.util.Hashtable;
import java.awt.event.*;
import javax.swing.event.*;
import java.applet.Applet;
public class Combox extends JApplet
{
private Drawing drawing;
        private JSlider dJSlider;
        private JComboBox comb;
        private JComboBox alfa;
private Container panel;
        private int id; //PlotEnergy
        private String currentPattern;
        private String af[] = {"Paint","No Paint"};
        private double scale=1;
        private int a;
        private String energyId[];
        private GridBagLayout layout;
        private GridBagConstraints gbc;
        
public void init()
{
panel = getContentPane();
                drawing = new Drawing(a,id,scale);
                TestCell p = new TestCell();
                p.energyId();
                energyId = p.getenergyId();
                panel.add(drawing);
                panel.add(new getSlider(),BorderLayout.NORTH);
                panel.add(new getComboPanel(),BorderLayout.EAST);//[B]wrong here[/B]
}
        
        class  getSlider extends JPanel {
            public getSlider(){
                int min = 1, max = 16, inc = 5;
                dJSlider = new JSlider(min, max, 6);
                dJSlider.setMajorTickSpacing(5);
                dJSlider.setMinorTickSpacing(1);
                dJSlider.setSnapToTicks(true);
                dJSlider.setLabelTable(getLabelTable(min, max, inc));
                dJSlider.setPaintTicks(true);
                dJSlider.setPaintLabels(true);
                dJSlider.addChangeListener(
                        new ChangeListener() // anonymous inner class
                        // handle change in slider value
                       {
                            public void stateChanged(ChangeEvent e)
                            {
                               int value = ((JSlider)e.getSource()).getValue();
                               double scale = (value+4)/10.0;drawing.setscale(scale);
                            }
                        }
                );    
                add(dJSlider);          
            }   
   
        private Hashtable getLabelTable(int min, int max, int inc) {
        Hashtable<Integer, JLabel> table = new Hashtable<Integer, JLabel>();
        for(int j = min; j <= max; j+=inc) {
            String s = String.format("%.1f", (j+4)/10.0);
            table.put(Integer.valueOf(j), new JLabel(s));
        }
        return table;
    }
}
          
        class getComboPanel extends JPanel {
         
             public getComboPanel(){
              
                currentPattern = energyId[0];
                comb = new JComboBox(energyId);
 
                gbc = new GridBagConstraints();
                addComponent(this,comb,0,0,1,1,GridBagConstraints.NONE, GridBagConstraints.CENTER);
                comb.setEditable(false);
                comb.setForeground (Color.BLUE);
                comb.setBackground (Color.GREEN);
 
                comb.setAlignmentX(Component.LEFT_ALIGNMENT);
                comb.addActionListener(
                        new ActionListener() // anonymous inner class
                        {
                            public void actionPerformed(ActionEvent e)
                            {
                               JComboBox cb = (JComboBox)e.getSource();
                               id = cb.getSelectedIndex();
                               drawing.setid(id);
                            }
                        }
                );
 
                alfa = new JComboBox(af);
                addComponent(this,alfa,0,1,1,1,GridBagConstraints.NONE, GridBagConstraints.CENTER);
                alfa.setEditable(false);
                alfa.setForeground(Color.BLUE);
                alfa.setBackground(Color.GREEN);
                alfa.setAlignmentX(Component.LEFT_ALIGNMENT);
                alfa.addActionListener(
                        new ActionListener() // anonymous inner class
                        {
                            public void actionPerformed(ActionEvent e)
                            {
                               JComboBox cc = (JComboBox)e.getSource();
                               a = cc.getSelectedIndex();
                               drawing.seta(a);
                            }
                        }
                );
                 add(comb);
                 add(alfa);
        }            
        }             
        
         private void addComponent(Container container, Component component,
                 int row, int column, int width, int height, int fill, int anchor)
         {
             gbc.gridx = column;
             gbc.gridy = row;
             gbc.gridwidth = width;
             gbc.gridheight = height;
             gbc.fill = fill;
             gbc.anchor = anchor;
             layout.setConstraints(component,gbc);
             container.add(component);
         }
 
 class Drawing extends JPanel 
{
    final int TRANSITION = 100; // Transition x,y coordinates of cells.
    private double x1, y1, x2, y2; // to plot lines from (x1,y1) to (x2,y2)
 
    private double xCells[][]; // Every cell's points's x coordinates array
    private double yCells[][]; // Every cell's points's y coordinates array
    private double rgb[][]; // Color red, green, blue for each point in each cell
   
    private double red[][];
    private double green[][];
    private double blue[][];
        private double lineWidth;
    private int sideId;
    private int sidesTotalNumber; // Total sides number for all cells
    private int rgbLength; // Total rgb color group number for all cells at each point
    private int cellsPointsNumber[]; // point numbers of each cell.(each cell has how many points)
    private int numberofCells;
    private int numberofsets;
    int a,id;
    double scale;
    Drawing(int a, int id, double scale) 
    {            this.a = a;
                 this.id = id;
                 this.scale = scale;
    }
    
    public void setscale(double scale)
    {
         this.scale = scale; 
         repaint();
    }
            
    public void setid(int id)
    {
        this.id = id;
        repaint();
    }
    
    public void seta(int a)
    {
        this.a = a;
        repaint();
    }
    
    public void paintComponent(Graphics g)
    {
            super.paintComponent( g ); // call superclass's paint method
            this.setBackground( Color.WHITE );
            Graphics2D g2d = (Graphics2D)g; // cast g to Graphics 2D
               
            getDrawingData();
            if (a==0)
                drawPolygon(g2d);  
            drawSides(g2d);
 }
   // end method paintComponent
   
      public void getDrawingData()
      {
          TestCell p = new TestCell();
          p.cellData();
         
          p.rgbs();
          xCells = p.getxCells();
          yCells = p.getyCells();
 
          sidesTotalNumber = p.getsidesTotalNumber();
          red = p.getred();
          green = p.getgreen();
          blue  = p.getblue();
          rgbLength = p.getrgbLength();
          cellsPointsNumber = p.getcellsPointsNumber();//array: each cell has how many points
          numberofCells = p.getnumberofCells();
          numberofsets  = p.getnumberofsets();
 
            for(int i = 0; i < numberofCells; i++)
            { 
              for(int j = 0; j<cellsPointsNumber[i]; j++)
              {
                  xCells[i][j] = (xCells[i][j])*scale+TRANSITION;
                  yCells[i][j] = (yCells[i][j])*scale+TRANSITION;
              }
          }
       }
    
       public void drawSides(Graphics2D g2d)
       {
           g2d.setColor(Color.GRAY);
            g2d.setStroke(new BasicStroke((float)lineWidth));
            for (int i = 0; i<numberofCells; i++)
            {
                for (int j = 0; j<cellsPointsNumber[i]-1; j++)
                {  
                    x1 = xCells[i][j];
                    y1 = yCells[i][j];
                    x2 = xCells[i][j+1];
                    y2 = yCells[i][j+1];
                    Line2D line = new Line2D.Double(x1,y1,x2,y2);
                    g2d.draw(line);// draw Sidess here
                } 
             }
            }
       
        public void drawPolygon(Graphics2D g2d)
       {
             for (int i = 0; i<numberofCells; i++)
             {
                Polygon poly = new Polygon();
                float r  = (float)red[i][id]; 
                 // red for ith cell,id is from 0 to numberofsets-1
                 // if id=0, means "Mixture"
                float g  = (float)green[i][id]; // green for ith cell
                float b  = (float)blue[i][id]; // blue for ith cell
                List<Integer> xList = new ArrayList<Integer>(); 
                List<Integer> yList = new ArrayList<Integer>();
                for (int j = 0; j<cellsPointsNumber[i]; j++)
                {  
                    xList.add((int)(xCells[i][j]));
                    yList.add((int)(yCells[i][j]));
                } 
                Integer[] x = xList.toArray(new Integer[xList.size()]);
                Integer[] y = yList.toArray(new Integer[yList.size()]);
                for (int s = 0; s<xList.size(); s++)
                {
                    poly.addPoint(x[s],y[s]);
                }
                g2d.setColor(new Color(r, g, b));// transparent drawing
                  g2d.fillPolygon(poly);
              }  
       }
 }   
 
       public static void main(String[] args)
            {
            JFrame appletFrame = new JFrame("My Applet");
            Applet theApplet = new Combox();
            appletFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            appletFrame.setSize(800,800);
            appletFrame.add(theApplet,"Center");
            theApplet.init();
            appletFrame.setVisible(true);
            }
}

ignore it, i have gotten.
poster closed.

just for the record, even though this was closed, i'm moving it to the more appropriate intermediate form