Displaying picture taken from BLOB in an Image of Frame

Last Modified On : 28-july-2003

 // 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