How to make a histogram normalize and equalize in java using the JAI library?

I am building an application in java using the Swing component and the JAI library. I am making a histogram of a black and white or gray image. Is this a correct histogram method? If correct, then how can I normalize and equalize the histogram in my application in java using the JAI library? My code is below. in my code, I create a BufferedImage object and then create and create a histogram of this image.    enter code here

    import java.awt.Color;
    import java.awt.Graphics;
    import java.awt.image.BufferedImage;
    import java.io.IOException;
    import javax.media.jai.JAI;
    import javax.media.jai.PlanarImage;
    import javax.swing.*;

    public class FinalHistogram extends JPanel {

   static int[] bins = new int[256];
   static int[] newBins = new int[256];
   static int x1 = 0, y1 = 0;
   static PlanarImage image = JAI.create("fileload", "alp_finger.tiff");                      
   static BufferedImage bi = image.getAsBufferedImage();

   FinalHistogram(int[] pbins) {
    for (int i = 0; i < 256; i++) {
        bins[i] = pbins[i];
        newBins[i] = 0;
    }

    repaint();
   }

   @Override
   protected void paintComponent(Graphics g) {

    for (int i = 0; i < 256; i++) {

        g.drawLine(150 + i, 300, 150 + i, 300 - (bins[i] / 300));

        if (i == 0 || i == 255) {
            String sr = new Integer((i)).toString();
            g.drawString(sr, 150 + i, 305);
        }

        System.out.println("bin[" + i + "]===" + bins[i]);
    }
  }

  public static void main(String[] args) throws IOException {

    int[] sbins = new int[256];
    int pixel = 0;
    int k = 0;

     for (int x = 0; x < bi.getWidth(); x++) {
        for (int y = 0; y < bi.getHeight(); y++) {
            pixel = bi.getRaster().getSample(x, y, 0);
             k = (int) (pixel / 256);
            sbins[k]++;  

       //pixel = bi.getRGB(x, y) & 0x000000ff;
       //k=pixel;

       //int[] pixels = m_image.getRGB(0, 0, m_image.getWidth(), m_image.getHeight(),     null, 0, m_image.getWidth());
      //short currentValue = 0;
      //int red,green,blue;
      //for(int i = 0; i<pixels.length; i++){           
            //red = (pixels[i] >> 16) & 0x000000FF;
            //green = (pixels[i] >>8 ) & 0x000000FF;
            //blue = pixels[i] & 0x000000FF;
            //currentValue = (short)((red + green + blue) / 3); //Current value gives            the average //Disregard the alpha
            //assert(currentValue >= 0 && currentValue <= 255);   //Something is awfully wrong if this goes off...
            //m_histogramArray[currentValue] += 1;    //Increment the specific value of the array
    //}

        }
     }



    JTabbedPane jtp = new JTabbedPane();
    jtp.addTab("Histogram", new JScrollPane(new FinalHistogram(sbins)));

    JFrame frame = new JFrame();
    frame.setSize(500, 500);
    frame.add(new JScrollPane(jtp));
    frame.setVisible(true);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
   }