I am having trouble folowing this http://hrycan.com/2012/03/28/primefaces-lazy-loading-datatable-for-jsf2/
It says I should just run
mvn jetty:run
I had this problem too. I started jetty:run
from within Eclipse using a "Maven Build" run configuration.
The problem was, within my Maven Build run configuration, the "base directory" (i.e. the working directory used by the mvn executable) was set incorrectly. Setting the base directory to the directory containing the pom.xml
fixed the problem.