Parse is an alias for org.apache.nutch.parse.ParseSegment
The class parses contents in one segment. It assumes, under the given segment, the existence of ./fetcher_output/, which is typically generated after a non-parsing fetcher run (i.e., fetcher is started with option -noParsing or as default 'false' boolean value as specified in nutch-default.xml).
Contents in one segment are parsed and saved in these steps:
1. ./fetcher_output/ and ./content/ are looped together (possibly by multiple ParserThreads), and content is parsed for each entry. The entry number and resultant ParserOutput are saved in ./parser.unsorted.
2. ./parser.unsorted is sorted by entry number, result saved as ./parser.sorted.
3. ./parser.sorted and ./fetcher_output/ are looped together. At each entry, ParserOutput is split into ParseDate and ParseText, which are saved in ./parse_data/ and ./parse_text/ respectively. Also updated is FetcherOutput with parsing status, which is saved in ./fetcher/.
In the end, ./fetcher/ should be identical to a directory produced as a result from the fetcher being run WITHOUT option -noParsing e.g. fetching and parsing in the same command. N.B. This is not suggested in a production environment.
By default, intermediates ./parser.unsorted and ./parser.sorted are removed at the end, unless option -noClean is used. However ./fetcher_output/ is kept intact.
Check Fetcher.java and FetcherOutput.java for further details.
Usage: bin/nutch parse <segmentdir>
<segmentdir>: This should be the path to the segment directory containing our data for parsing.