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Nutch: Invoke in Java, not command line?

Am I being thick or is there really no way to invoke Apache Nutch through some Java code programmatically? Where is the documentation (or a guide or tutorial) on how to do this? Google has failed me. So I actually tried Bing. (Yes, I know, pathetic.) Ideas? Thanks in advance.

(Also, if Nutch is a crap-shoot any other crawlers written in Java that are proven to be reliable on an internet scale with actual documentation?)

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ChrisJF Avatar asked Mar 24 '11 14:03

ChrisJF


1 Answers

If you take a look inside bin/nutch script, you'll see that it invokes a Java class corresponding to your command:

# figure out which class to run
if [ "$COMMAND" = "crawl" ] ; then
  CLASS=org.apache.nutch.crawl.Crawl
elif [ "$COMMAND" = "inject" ] ; then
  CLASS=org.apache.nutch.crawl.Injector
elif [ "$COMMAND" = "generate" ] ; then
  CLASS=org.apache.nutch.crawl.Generator
elif [ "$COMMAND" = "freegen" ] ; then
  CLASS=org.apache.nutch.tools.FreeGenerator
elif [ "$COMMAND" = "fetch" ] ; then
  CLASS=org.apache.nutch.fetcher.Fetcher
elif [ "$COMMAND" = "fetch2" ] ; then
  CLASS=org.apache.nutch.fetcher.Fetcher2
elif [ "$COMMAND" = "parse" ] ; then
  CLASS=org.apache.nutch.parse.ParseSegment
elif [ "$COMMAND" = "readdb" ] ; then
  CLASS=org.apache.nutch.crawl.CrawlDbReader
elif [ "$COMMAND" = "convdb" ] ; then
  CLASS=org.apache.nutch.tools.compat.CrawlDbConverter
elif [ "$COMMAND" = "mergedb" ] ; then
  CLASS=org.apache.nutch.crawl.CrawlDbMerger
elif [ "$COMMAND" = "readlinkdb" ] ; then
  CLASS=org.apache.nutch.crawl.LinkDbReader
elif [ "$COMMAND" = "readseg" ] ; then
  CLASS=org.apache.nutch.segment.SegmentReader
elif [ "$COMMAND" = "segread" ] ; then
  echo "[DEPRECATED] Command 'segread' is deprecated, use 'readseg' instead."
  CLASS=org.apache.nutch.segment.SegmentReader
elif [ "$COMMAND" = "mergesegs" ] ; then
  CLASS=org.apache.nutch.segment.SegmentMerger
elif [ "$COMMAND" = "updatedb" ] ; then
  CLASS=org.apache.nutch.crawl.CrawlDb
elif [ "$COMMAND" = "invertlinks" ] ; then
  CLASS=org.apache.nutch.crawl.LinkDb
elif [ "$COMMAND" = "mergelinkdb" ] ; then
  CLASS=org.apache.nutch.crawl.LinkDbMerger
elif [ "$COMMAND" = "index" ] ; then
  CLASS=org.apache.nutch.indexer.Indexer
elif [ "$COMMAND" = "solrindex" ] ; then
  CLASS=org.apache.nutch.indexer.solr.SolrIndexer
elif [ "$COMMAND" = "dedup" ] ; then
  CLASS=org.apache.nutch.indexer.DeleteDuplicates
elif [ "$COMMAND" = "solrdedup" ] ; then
  CLASS=org.apache.nutch.indexer.solr.SolrDeleteDuplicates
elif [ "$COMMAND" = "merge" ] ; then
  CLASS=org.apache.nutch.indexer.IndexMerger
elif [ "$COMMAND" = "plugin" ] ; then
  CLASS=org.apache.nutch.plugin.PluginRepository
elif [ "$COMMAND" = "server" ] ; then
  CLASS='org.apache.nutch.searcher.DistributedSearch$Server'
else
  CLASS=$COMMAND
fi

# run it
exec "$JAVA" $JAVA_HEAP_MAX $NUTCH_OPTS -classpath "$CLASSPATH" $CLASS "$@"

From there on, it's only the question of looking at the API docs and, if necessary, source code for those classes.

like image 118
Vojislav Stojkovic Avatar answered Oct 19 '22 04:10

Vojislav Stojkovic