Help in retrieveing Blob from Oracle db and display it on a web page

Question

I am using Sun Studio creator2 and this is what I want to achieve:
When I click on "Load" button, the image is displayed on the web page(the application is a web application)
I have dropped the "image" object from the pallette
Having the database image displayed in the image field, when I enter the image ?Id? and click on the ?Load? button.
Here is my piece of code:
public String loadButton_action() {
HttpServletRequest request = null;
HttpServletResponse response = null;
String connectionURL = "jdbc:oracle:thin:@//localhost:1521/cdecentre1";;
/*declare a resultSet that works as a table resulted by execute a specified
sql query. */
ResultSet rs = null;
// Declare statement.
PreparedStatement psmnt = null;
// declare InputStream object to store binary stream of given image.
InputStream sImage;
Connection connection = null;
String driverName = "oracle.jdbc.driver.OracleDriver";
String dbName = "cdecentre1";
String userName = "christian";
String password = "cc";
String theid = (String)idField.getValue(); //reading the image id
try{
Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
connection = DriverManager.getConnection(connectionURL, userName, password);
/* prepareStatement() is used for create statement object that is
used for sending sql statements to the specified database. */
psmnt = connection.prepareStatement("SELECT image FROM CHRISTIAN.PICTURES WHERE id = ?");
psmnt.setString(1, theid);
rs = psmnt.executeQuery();
if(rs.next()) {
byte[] bytearray = new byte[1048576];
int size=0;
sImage = rs.getBinaryStream(1);
//response.reset();
response.setContentType("image/jpeg");
while((size=sImage.read(bytearray))!= -1 ){
response.getOutputStream().write(bytearray,0,size);
rs.close();
psmnt.close();
connection.close(); } }
} catch(Exception ex){
System.out.println("error :"+ex);
return null; }
At the moment, when I click on the ?Load? button, the image is not present in the image field.
I am only obtaining a message inside the message component.
What should I do to have the image displayed in on the web page?
Your help will be highly appreciated.

Answer 1

A comprehensive dissertation from Javaworld: http://www.javaworld.com/javaworld/jw-05-2000/jw-0505-servlets.html
Published 05/05/2000, ergo Java 1.0/1 era... still a valid explanation of the problem and the fundamental solution, but take the code (esp ImageIO) from here
http://blog.codebeach.com/2008/02/creating-images-in-java-servlet.html
   1. package com.codebeach.servlet; 
   2.  
   3. import java.io.*; 
   4. import javax.servlet.*; 
   5. import javax.servlet.http.*; 
   6. import java.awt.*; 
   7. import java.awt.image.*; 
   8. import javax.imageio.*; 
   9.  
  10. public class ImageServlet extends HttpServlet 
  11. { 
  12.     public void doGet(HttpServletRequest req, HttpServletResponse res) 
  13.     { 
  14.         //Set the mime type of the image 
  15.         res.setContentType("image/jpeg"); 
  16.  
  17.         try 
  18.         { 
  19.             Create an image 200 x 200 
  20.             BufferedImage bufferedImage = new BufferedImage(200, 200, BufferedImage.TYPE_INT_RGB); 
  21.  
  22.             //Draw an oval 
  23.             Graphics g = bufferedImage.getGraphics(); 
  24.             g.setColor(Color.blue); 
  25.             g.fillOval(0, 0, 199,199); 
  26.  
  27.             Free graphic resources 
  28.             g.dispose(); 
  29.  
  30.             //Write the image as a jpg 
  31.             ImageIO.write(bufferedImage, "jpg", res.getOutputStream()); 
                    ////////////// NICE !!!! //////////////
  32.         } 
  33.         catch (IOException ioe) 
  34.         { 
  35.            e.printStackTrace();
  36.         } 
  37.     } 
  38. }  Edited by: corlettk on 19/01/2009 23:22 ~~ {color:#FF0000}Never{color} eat an exception!