tree: 3ab9865572d70d930f7155073be91525411193c2 [path history] [tgz]
  1. src/
  2. build.xml
  3. ivy.xml
  4. plugin.xml

indexer-csv plugin for Nutch

indexer-csv plugin is used for writing documents to a CSV file. It does not work in distributed mode, the output is written to the local filesystem, not to HDFS, see NUTCH-1541. The configuration for the index writers is on conf/index-writers.xml file, included in the official Nutch distribution and it's as follow:

<writer id="<writer_id>" class="org.apache.nutch.indexwriter.csv.CSVIndexWriter">

Each <writer> element has two mandatory attributes:

  • <writer_id> is a unique identification for each configuration. This feature allows Nutch to distinguish each configuration, even when they are for the same index writer. In addition, it allows to have multiple instances for the same index writer, but with different configurations.

  • org.apache.nutch.indexwriter.csv.CSVIndexWriter corresponds to the canonical name of the class that implements the IndexWriter extension point. This value should not be modified for the indexer-csv plugin.


The mapping section is explained here. The structure of this section is general for all index writers.


Each parameter has the form <param name="<name>" value="<value>"/> and the parameters for this index writer are:

Parameter NameDescriptionDefault value
fieldsOrdered list of fields (columns) in the CSV fileid,title,content
charsetEncoding of CSV fileUTF-8
separatorSeparator between fields (columns),
valuesepSeparator between multiple values of one field|
quotecharQuote character used to quote fields containing separators or quotes"
escapecharEscape character used to escape a quote character"
maxfieldlengthMax. length of a single field value in characters4096
maxfieldvaluesMax. number of values of one field, useful for, e.g., the anchor texts field12
headerWrite CSV column headerstrue
outpathOutput path / directory (local filesystem path, relative to current working directory)csvindexwriter