Neither JBoss AS 4.2.3 nor 5.0.1 contains that class. Which JBoss AS are you using? Or do you mean another JBoss-branded product (other than JBoss AS)?

Apparently what you are looking at is the Guide for JBoss AS 4.0.1, but the same class is still mentioned in the Guide for 4.0.5. I even looked in the 4.2.2 Guide and that class is still mentioned.

Looks like someone asked this same question about 5 years ago: http://www.jboss.org/index.html?module=bb&op=viewtopic&t=68096.

One of the commentors offered a reply which lead me to click on the "Examples" link next to the 4.0.5 documentation on the docs home page (https://www.jboss.org/community/docs/DOC-12898), and I found the class in question in that zip file.

1) Download example codes from
http://docs.jboss.org/jbossas/jboss4guide/r1/jboss4guide.zip

2) unzip and to go
\examples\src\main\org\jboss\util\ChapterExRepository.java