Servlet add text to image!

Question

Hi I'm a newbie to java servlet, how can I add text to an image?
Thanks

Answer 1

hi, thank you for your message! actually java program allow you to add text to an image. Here's a sample code I found from the Net.
Actually there are a no of other examples, but all failed at my server.
My linux server is FC4.
The following code stated that:
* Note: on X-based systems like Linux or Solaris,
* this servlet probably won't work unless the host
* is running an X server
So what so I do, how to change the setting of my server?
Anyone pls help!
import java.awt.*;
import java.awt.image.*;
import javax.imageio.*;
import javax.imageio.stream.*;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
* This servlet provides the service of labeling an
* image with a text string. The caller of the
* servlet gets to specify the image (local file or
* URL), the text string, text size, and the color.
* This servlet has a large number of limitations,
* the foremost being that it will only write JPEG
* images (with minimal compression).
* <p>
* Note: on X-based systems like Linux or Solaris,
* this servlet probably won't work unless the host
* is running an X server.
* <p>
* This servlet requires the JAI/IIO package to be
* installed to perform JPG image output.
* <p>
* Example img src URL:<br>
* http://www.myhost.com/servlet/ImageLabelServer?src=http://www.foobar.com/logo.jpg&text=Foobar+Logo&size=28&color=90f000ff
* <br>
* This sample will cause the servlet to got retrieve the image logo.jpg from
* the www.foobar.com web site, and then overlay the text "Foobar Logo" in
* partially transparent purple 28-point text.
* @author Neal Ziring
public class ImageLabelServlet extends HttpServlet
public static final String PARM_IMAGE = "src";
public static final String PARM_TEXT = "text";
public static final String PARM_SIZE = "size";
public static final String PARM_COLOR= "color";
public static final String IMG_OUT_SUFFIX = "jpg";
public static final String IMG_OUT_MIME = "image/jpeg";
/* need these for doing AWT stuff */
static Component ob = null;
static Toolkit tk = null;
* Initialize stuff we need for this servlet.
public void init(ServletConfig conf) {
if (tk == null) tk = Toolkit.getDefaultToolkit();
if (ob == null) { ob = new Frame(); ob.addNotify(); }
* Just call the doGet method to handles posts.
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, java.io.IOException
doGet(req,resp);
* Process a request - we look for the parameters
* listed above. Our output consists of an image
* in image/jpeg format, or a 404 message if we
* couldn't load the requested image.
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, java.io.IOException
String src = req.getParameter(PARM_IMAGE);
if (src == null || src.length() == 0) {
resp.sendError(resp.SC_BAD_REQUEST, "No source image specified");
return;
String text = req.getParameter(PARM_TEXT);
if (text == null || text.length() == 0)
text = (new Date()).toString();
String size = req.getParameter(PARM_SIZE);
int textSize = 14;
try { textSize = Integer.parseInt(size); }
catch (Exception ie) { }
String color = req.getParameter(PARM_COLOR);
int textColor = 0x666666;
try {
if (color.startsWith("#")) color = color.substring(1);
textColor = (int)(Long.parseLong(color, 16) & 0x0ffffffff);
} catch (Exception ie2) { }
float cq = 0.01F;
String qual = req.getParameter("q");
if (qual != null && qual.length() > 0) {
try { cq = (float)(Double.parseDouble(qual)); }
catch (Exception ie) { }
Font f = new Font("Sans-serif", Font.BOLD, textSize);
Image img = null;
if (src.indexOf('/') >= 0 || src.indexOf(':') >= 0) { try {
URL u = new URL(src);
img = tk.createImage(u);
} catch (Exception ie3) { } }
else { try {
img = tk.createImage(src);
} catch (Exception ie4) { } }
MediaTracker mt = new MediaTracker(ob);
mt.addImage(img, 2);
try { mt.waitForID(2); } catch (InterruptedException eix) { }
if (mt.isErrorID(2)) img = null;
if (img == null) {
resp.sendError(resp.SC_NOT_FOUND, "Could not load source image");
int w, h;
w = img.getWidth(ob);
h = img.getHeight(ob);
BufferedImage img2 = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
if (img2 == null) System.err.println("img2 is Null!");
Graphics g = img2.getGraphics();
if (g == null) System.err.println("Graphics is Null!");
Color c = new Color(textColor, (((textColor >> 24) & 0xff) != 0));
g.setColor(c);
g.setFont(f);
g.drawImage(img, 0, 0, ob);
g.drawString(text, textSize/2, (textSize * 5)/4);
img.flush(); img = null;
Iterator writers = ImageIO.getImageWritersBySuffix(IMG_OUT_SUFFIX);
if (!(writers.hasNext())) {
resp.sendError(resp.SC_CONFLICT, "Cannot write JPEG image!");
return;
if (!writeImageOut((ImageWriter)(writers.next()), img2, resp, cq)) {
resp.sendError(resp.SC_CONFLICT, "Writing image failed");
return;
img2.flush(); img2 = null;
return;
* Write out the image to the servlet response stream.
* This method always sends a mime type of IMG_OUT_MIME.
boolean writeImageOut(ImageWriter wr, BufferedImage img,
HttpServletResponse resp, float cq)
boolean ret = false;
resp.setContentType(IMG_OUT_MIME);
try {
OutputStream oos = resp.getOutputStream();
ImageOutputStream ios = ImageIO.createImageOutputStream(oos);
wr.setOutput(ios);
ImageWriteParam parm = wr.getDefaultWriteParam();
parm.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
parm.setCompressionQuality(cq);
cq = parm.getCompressionQuality();
IIOImage ii = new IIOImage(img, null, null);
wr.prepareWriteSequence(null);
wr.writeToSequence(ii, parm);
wr.endWriteSequence();
ios.flush();
wr.dispose();
ios.close();
ret = true;
catch ( Exception ioe) {
System.err.println("Error in image writing: " + ioe);
ioe.printStackTrace();
return ret;
}