如果您查看bin/nutch脚本，您将看到它调用与您的命令对应的Java类：

# 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" $CLASS "$@"从那以后，只有查看API docs以及必要时查看这些类的源代码的问题。