Hi Kaiwii, If you look at nutch-extensionpoints/plugin.xml you will see a short comment which states "...that plugins can define extension points as well to be extendable". The the case of the ulrnormalizer series of plugins we can specify settings (within nutch-site.xml) for which urlnormalizer plugins we wish to use, in which order we wish to use them, etc.
On Thu, Aug 25, 2011 at 4:31 AM, Kaiwii Ho <[email protected]> wrote: > I'm a freshman learning about the nutch. > Here,I have serval questions: > 1、URLNormalizer is a kind of a ExtensionPoint.But why does it implement the > Pluggable as other extensionpoint does? > And further-more,do any difference > exist between the URLNormalizer and the other ExtensionPoint leading > the URLNormalizer's not implementing the Pluggable? > The honest truth here is I don't know, however I what difference would you expect to get from comparing a pluggable urlnormalizer with accessing the nutch-extensionpoint directly... is there any reason for this... IMHO it would be easier to utilise the functionality of a particular plugin in the usual way, through nutch-site.xml 2、while URLNormalizer not implementing the Pluggable,everything seems to > work well.So,I wonder whether it is necessary to make the extensionpoint > implement the Pluggable? > As above... > > Waiting for ur answer.And thank u! > -- *Lewis*
