Introduction

By default, Kaptcha is very easy to setup and use and the default output produces a captcha that should be fairly hard to bust. The captcha's it produces by default look very similar to the one above. If you would like to change the look of the output, there is several configuration options and the framework is modular so you can write your own morphing code.

simplecaptcha is a wonderful product. However, it seems that simplecaptcha is unmaintained and there is some problems running the project with JDK 1.5 and the HTTP headers the servlets output. There is a bunch of bug reports, patches and forum messages noting these facts and no new releases or changes in about three years.

Why not use jCaptcha? It also is a great project, but it is more of a library rather than a quick solution. The default captcha's that it produces are either too hard to read or not good enough for use on a public website. It's also rather slow. Sure, it is possible to spend a bunch of time learning their api's to produce something useful and I've done that, but the reality is that I would prefer a simple jar I can just drop into my project, put a couple lines in my web.xml and go from there. Note: Because jCaptcha and Kaptcha both use different versions of the pixels library you can't use both of them at the same time in the same web application.

So, that's the reason and justification for kaptcha. This project is all about a supported, modern version of the existing code. Why the name kaptcha? Because the company I work for (NSFW) starts with a k.

Final Thoughts

• If you have any questions or comments send me a note. Please note that if you are new to web programming, never used Java before or just generally clueless as to the workings of the internets, I'm probably not going to respond to your email. I've made it as easy as possible to integrate kaptcha with your project, however this really is a product for people who know what they are doing.

• If you have a valid issue with the functionality or design of kaptcha, please click the Issues tab and file one.

• I've spent a lot of time on this project. Donations are welcome and very much appreciated. No amount is too small. Click the button below to donate through paypal. It is fast and simple.

Changes

v2.3.1 - Unreleased

• All fixes are in the issue tracker

v2.3 - July 25, 2008

• All fixes are in the issue tracker

v2.2 - Mar 21, 2008

• Added Unit Tests
• Fixed bug with ShadowGimpy config
• Use JavaIO to generate the images
• Send all recommended no-cache http headers
• Bit more code refactoring and cleanup.

v2.1 - Feb 15, 2008

• Upgraded to Retroweaver 2.0.4.
• Fixed issue with build system.
• Reformatted all the source code.
• Applied the patch from cliffano that refactored the configuration and various other cleanup. I changed his configuration patch a bit as well.
• Deleted SimpleKaptcha servlet as it was unnecessary, unmaintained and had several usage issues.
• Add no caching and content type response headers to KaptchaServlet

v2.0 - Oct 2, 2007

• Upgraded to Retroweaver 2.0.1.
• Mass code cleanup and refactoring.
• Provide documentation for the web.xml init parameters. @see ConfigParameters.
• A couple small bugs have been fixed.

v1.2

• JDK 1.4 is supported by adding Retroweaver support to the build system and a jdk1.4 jar is included with the distribution.

v1.1

• Re-organized code a whole lot. Moved and renamed a lot of files. The code layout is much more clear now.
• Removed all references to 'simple' in the Constants.

v1.0

• Re-organized code a bit.
• Added Eclipse project files.
• Removed a bunch of duplicate and unused code.
• Zero warnings/errors in Eclipse.
• Rewrote the ant build file.