mando il codice della mia jsp nel caso possa servire a qualcuno...
ciao
codice:
<%@ page contentType="image/jpeg" import="java.awt.image.*,java.awt.*,com.sun.image.codec.jpeg.*" %>
<%
int size_v = 50;
int size_h = 200;
BufferedImage bfm = new BufferedImage(size_h,size_v,BufferedImage.TYPE_INT_RGB);
Graphics g = bfm.getGraphics();
g.setColor(Color.yellow);
g.fillRect(0,0,size_h,size_v);
g.setColor(Color.black);
g.setFont(new Font("Courier", Font.BOLD, 10));
g.drawString(java.net.InetAddress.getLocalHost().toString()+" @ "+String.valueOf(System.currentTimeMillis()), 10, 20);
JPEGImageEncoder enc = JPEGCodec.createJPEGEncoder(response.getOutputStream());
enc.encode(bfm);
response.getOutputStream().close();
%>