Need an ascii image format!

[Bura Tino]

Hi,

I developing a system using JSP. People familiar with this technology
know that ServerPages are easier to maintain than Servlets, but they
can only have ASCII output.

With that as the backdrop, here's what I want to accomplish. I want
clicking on a link to cause a script to be executed on the server but
-->I don't want the browser to jump to another page<--.

A solution that I conceived was to have javascript like

someimage.src = 'http://myscript'

This will accomplish the task and it would be great if myscript return
an image of a checked checkbox! But, because of JSP limitations this
would need to be an ASCII image.

So my question is twofold:
1. Are there convenient ASCII image formats?
2. Is there another way to accomplish what I want (trigger some action
on the server without jumping to another page and using js to display
a sensible response - something like a check)?

Thanks!

Bura

[Richard Cornford]

Bura Tino wrote:

I developing a system using JSP. People familiar with this technology
know that ServerPages are easier to maintain than Servlets, but they
can only have ASCII output.

<snip>

Not true, you can output anything from a JSP because a JSP is a
servelet. You just have to be careful not to output any character data
(including CR/LF pairs) prior to resetting the response and starting to
output binary e.g.:-

<%@ page language="java" import=",java.io.*,java.util.*"%><%!
final static byte[] spacer = {
71, 73, 70, 56, 57, 97, 1, 0, 1, 0, -128, 1, 0, -1, -1, -1,
0, 0, 0, 44, 0, 0, 0, 0, 1, 0, 1, 0, 0, 2, 2, 68, 1, 0, 59
};
%><%
try{
response.reset();
response.setContentType("image/gif");
OutputStream outStream = response.getOutputStream();
synchronized(response.getOutputStream()){
outStream.write(spacer);
}
response.flushBuffer();
}catch(IOException e){
System.out.println("IO Exception details 1 : " + e.getMessage());
}catch(Exception e){
System.out.println("Exception details 2 : " + e.getMessage());
}%>

But JSP is OT here.

Richard.