Description
There is a typo in the extension id definition of the urlfilter-regex plugin.xml
<extension id="org.apache.nutch.net.urlfiler"
name="Nutch Regex URL Filter"
point="org.apache.nutch.net.URLFilter">
should be:
<extension id="org.apache.nutch.net.urlfilter"
name="Nutch Regex URL Filter"
point="org.apache.nutch.net.URLFilter">
Note that 'urlfiler' should be 'urlfilter'