Re: Random String Generator

[Ralph Daugherty <rdjfc@xxxxxxxxxxxxx>]

   The OP, Dave I think, and others may be interested in doing this I 
hope. I have completed isolating the Batik PNG classes and won't be 
using any supporting jars.

   Looking forward to hearing that someone is getting a CAPTCHA from 
this on the iseries.

 rd


Thorbjørn Ravn Andersen wrote:
> Ralph Daugherty skrev:
> > Hi Thorbjørn, I am already doing what you are suggesting. The class I 
> > started with is (as I posted back aways) 
> > org.apache.myfaces.custom.captcha.util and I am bringing in supporting 
> > classes for generating a PNG text image twisted based on this. It is 
> > Apache's robust CAPTCHA logic, unmodified.
> >   
> Hi.
>
> Please find below a proof-of-concept stand alone class that generates a 
> PNG image.  You need tomahawk.jar, the batik.jars and servlet.jar on the 
> classpath.  The DummyHttpServletResposeImplementation nested class is 
> needed to wrap the overridden outputStream.
>
> Regards,
>
> /Thorbjørn
>
> foo/Bar.java
> ====
> package foo;
>
> import java.awt.Color;
> import java.io.ByteArrayOutputStream;
> import java.io.File;
> import java.io.FileOutputStream;
> import java.io.IOException;
> import java.io.PrintWriter;
>
> import javax.servlet.ServletOutputStream;
> import javax.servlet.http.Cookie;
> import javax.servlet.http.HttpServletResponse;
>
> import org.apache.myfaces.custom.captcha.util.CAPTCHAImageGenerator;
> import org.apache.myfaces.custom.captcha.util.CAPTCHATextGenerator;
>
> public class Bar {
>
>    private static class DummyHttpServletResponseImplementation implements
>            HttpServletResponse {
>        public void setContentType(String arg0) {
>        }
>
>        public void setContentLength(int arg0) {
>        }
>
>        public PrintWriter getWriter() throws IOException {
>            return null;
>        }
>
>        public ServletOutputStream getOutputStream() throws IOException {
>            return null;
>        }
>
>        public String getCharacterEncoding() {
>            return null;
>        }
>
>        public void setStatus(int arg0, String arg1) {
>        }
>
>        public void setStatus(int arg0) {
>        }
>
>        public void setIntHeader(String arg0, int arg1) {
>        }
>
>        public void setHeader(String arg0, String arg1) {
>        }
>
>        public void setDateHeader(String arg0, long arg1) {
>        }
>
>        public void sendRedirect(String arg0) throws IOException {
>        }
>
>        public void sendError(int arg0, String arg1) throws IOException {
>        }
>
>        public void sendError(int arg0) throws IOException {
>        }
>
>        public String encodeUrl(String arg0) {
>            return null;
>        }
>
>        public String encodeURL(String arg0) {
>            return null;
>        }
>
>        public String encodeRedirectUrl(String arg0) {
>            return null;
>        }
>
>        public String encodeRedirectURL(String arg0) {
>            return null;
>        }
>
>        public boolean containsHeader(String arg0) {
>            return false;
>        }
>
>        public void addCookie(Cookie arg0) {
>        }
>    }
>
>    /**
>     * @param args
>     * @throws IOException
>     */
>    public static void main(String[] args) throws IOException {
>        CAPTCHAImageGenerator generator = new CAPTCHAImageGenerator();
>        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
>        HttpServletResponse response = new 
> DummyHttpServletResponseImplementation() {
>
>            ServletOutputStream sos = new ServletOutputStream() {
>                @Override
>                public void write(int b) throws IOException {
>                    baos.write(b);
>                }
>            };
>
>            @Override
>            public ServletOutputStream getOutputStream() throws 
> IOException {
>                return sos;
>            }
>        };
>        Color[] colors = new Color[] {Color.RED, Color.GREEN, Color.PINK, 
> Color.ORANGE, Color.CYAN};
>              Color startingColor = colors[(int) (Math.random() * 
> colors.length)];
>        Color endingColor = colors[(int) (Math.random() * colors.length)];
>        generator.generateImage(response, 
> CAPTCHATextGenerator.generateRandomText(), startingColor, endingColor);
>        System.out.println("PNG image in baos is " + baos.size() + " 
> bytes");
>        File f = new File("out.png");
>        FileOutputStream fos = new FileOutputStream(f);
>        fos.write(baos.toByteArray());
>        fos.close();
>    }
>
> }
>
> ====