program to display a picture taken from BLOB in a Framebased application

 /* -------------------------------------------------------------------------------
   create table players
   (  name varchar2(20),
      photo blob 
   );
  ------------------------------------------------------------------------------- */

import  javax.swing.*;
import  java.awt.*;
import  java.awt.event.*;
import  java.sql.*;
import  java.io.*;

public class DisplayBLOB extends JFrame implements ActionListener
{
    Connection con;
    Statement st;
    ResultSet rs;

    JLabel  lblimage = new JLabel();
    JLabel  lblname = new JLabel();

    JButton btnNext,btnPrev;

    public static void main(String args[])
    {
        new DisplayBLOB();
    }

    public ResultSet getResultSet()  throws Exception
    {
        // load oracle driver
        Class.forName("oracle.jdbc.driver.OracleDriver");

        // connect using OCI driver assuming program runs on the same machine as Oracle9i
        con = DriverManager.getConnection("jdbc:oracle:oci8:@","sri","sri");
        st = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
        rs = st.executeQuery("select name,photo from players");
        rs.next();
        return rs;
    }

    class WinCode extends WindowAdapter
    {
        public void windowClosing(WindowEvent evt)
        {
            System.exit(0);
        }
    }

    public DisplayBLOB()
    {

        super("Players");
        this.addWindowListener(new WinCode());

        try
        {
            rs = getResultSet();
            // create buttons
            btnNext = new JButton("Next");
            btnPrev = new JButton("Prev");

            btnNext.addActionListener(this);
            btnPrev.addActionListener(this);

            JPanel p = new JPanel();
            p.setLayout( new FlowLayout());
            p.add(btnPrev);
            p.add(btnNext);


            Container c = getContentPane();

            lblname.setHorizontalAlignment(SwingConstants.CENTER);
            lblimage.setHorizontalAlignment(SwingConstants.CENTER);

            c.add(lblname,"North");
            c.add(lblimage,"Center");

            c.add(p,"South");

            setSize(400,400);
            setVisible(true);

            displayPlayer();

        }
        catch(Exception ex)
        {
            System.out.println(ex.getMessage());
        }
    }

    public void displayPlayer() throws Exception
    {

        // display details of a player from current row in ResultSet

        lblname.setText(rs.getString(1));
        Blob   photo = rs.getBlob(2);

        byte b[] = new byte[(int) photo.length()];

        InputStream is = photo.getBinaryStream();

        is.read(b);

        Toolkit  tk = Toolkit.getDefaultToolkit();
        Image image = tk.createImage(b);  // create an image from array of bytes
        Icon img = new ImageIcon(image);
        lblimage.setIcon(img);

    }


    public void actionPerformed(ActionEvent evt)
    {
        try
        {

            if (evt.getSource() == btnNext)
            {
                if (!rs.isLast())  // if not at the last row in resultset
                    rs.next();
            }
            else
            {
                if ( ! rs.isFirst())   // if not at the first row in resultset
                    rs.previous();
            }

            displayPlayer();

        }
        catch(Exception ex)
        {
            System.out.println( ex.getMessage());
        }
    }

} // end of DisplayBlob