Copy the tag library descriptor file
(regexp/regexp.tld) to the /WEB-INF subdirectory of your web application.
Copy the tag library JAR file (regexp/regexp.jar)
to the /WEB-INF/lib subdirectory of your web application.
Add a <taglib> element to your web
application deployment descriptor in /WEB-INF/web.xml like this:
<taglib>
<taglib-uri>http://jakarta.apache.org/taglibs/regexp-1.0</taglib-uri>
<taglib-location>/WEB-INF/regexp.tld</taglib-location>
</taglib>
To use the tags from this library in your JSP pages, add the following directive at the top of each page:
<%@ taglib uri="http://jakarta.apache.org/taglibs/regexp-1.0" prefix="rx" %>
where "rx" is the tag name prefix you wish to use for tags from this library. You can change this value to any prefix you like.