Displaying Picture from blob

[vice]

I was able to upload picture to database using file upload and tomahawk.jar. But I don't know how to display the picture in jsf using seam.

If I just use HttpServlet I can write directly using:
response.setContentType("image/jpeg");
response.getOutputStream().write(productImage);

and in the xhtml I use:


How to get do this in seam? Anyone can help?

[stephenwilliams]

I would also be very interested in an answer to this question as I am trying to do the same thing. I have already implimented this with a servlet but I would like to do using a statefull session bean.

If anyone could please explain how this can be done I would be very greatfull indead.

Regards,
Stephen

[pmuir]

I wrote a sample solution http://jroller.com/page/pmuir?entry=dynamicimagecomponent_for_jsf, also, I believe Ajax4JSF contains the 'media' component which does this and more.

[stephenwilliams]

Hi

Thanks for the answer petemuir!

I would like to get he Ajax4jsf solution working as everywhere I read it should just work with seam 1.1 GA but I am have a problem...

I get the error...

javax.el.ELException: /home.xhtml: Bean: demo.PaintBean$$EnhancerByCGLIB$$6f0837bd, property: paint
 at com.sun.facelets.compiler.AttributeInstruction.write(AttributeInstruction.java:53)
 at com.sun.facelets.compiler.UIInstructions.encodeBegin(UIInstructions.java:39)
 at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:232)
 at com.sun.facelets.tag.jsf.ComponentSupport.encodeRecursive(ComponentSupport.java:239)

I added the following in my facelet...

<a4j:mediaOutput createContent="#{hello.renderImage}" value="#{hello.value}.jpg" element="img" mimeType="image/jpeg" />

the following to my bean...

public void renderImage(OutputStream out, Object data) throws IOException {
 BufferedImage img = new BufferedImage(100,
 50, BufferedImage.TYPE_INT_RGB);
 Graphics2D graphics2D = img.createGraphics();
 graphics2D.setBackground(Color.BLACK);
 graphics2D.setColor(Color.WHITE);
 graphics2D.clearRect(0, 0, 100, 50);
 graphics2D.drawLine(5, 5, 100 - 5, 50 - 5);
 graphics2D.drawChars(new String("Ajax4JSF").toCharArray(), 0, 8,
 40, 15);
 graphics2D.drawChars(new String("mediaOutput").toCharArray(), 0,
 11, 5, 45);
 ImageIO.write(img, "jpeg", out);
 }

the following to my interface...

public void renderImage(OutputStream out, Object data) throws IOException;

and then deployed it.


If anyone has allready done this I would really appreciate a small example.

[pmuir]

Probably you are better off asking this on the ajax4jsf forum/mailing list (whichever they use) as it's relevant to that than to Seam.

[stephenwilliams]

I have gotten one step further, hurray! My problem was that the ajax4jsf jars (ajax4jsf.jar and oscache-2.3.2.jar were not being deployed.


I now have the same problem that has been posted at

http://jboss.com/index.html?module=bb&op=viewtopic&p=3999655


I will continue there.

[smokingapipe]

I haven't looked at Peter's solution but I know it would be quite easy and efficient to write a plain old Servlet to do this. It is perfectly possible to use EntityManagers within Servlets, and serving an image from a Servlet is a good way to go. You avoid any overhead of Seam, JSF or anything else, and it can be done with just a few lines of code in a servlet.

[shane.bryzak]

The Seamspace example in CVS serves images from a servlet, and provides an image rescaling feature also. Take a look at ContentServlet.java, it's pretty straight forward - and it uses SeamServletFilter to set up the Seam contexts.

[stephenwilliams]

Thanks guys!

I will check it out. Ideally I would like to have a statefull bean that handels all the attributes and generates the image. Of couse if I don't manage this I will also try out peters solution or just a plain servlet.