kaptcha is abbreviation for "Completely Automated Public Turing test to tell Computers and Humans Apart".
Since google had contributed a jar to provide authentication function by means of picture for this aspect, it for unknown reason hadn't uploaded the jar onto
maven's central repository which give some bother to the maven users.
While having some trouble finding another repo manager which supports the kaptcha jar, I found someone had uploaded it to maven central with another groupId.
Just add the dependency description below to the pom.xml file in your project and go on your work as usual:
<dependency> <groupId>com.github.axet</groupId> <artifactId>kaptcha</artifactId> <version>0.0.9</version> </dependency>
For more information, refer to this post: https://code.google.com/p/kaptcha/issues/detail?id=12