Apache Solr Reference Guide Covering Apache Solr 6.0

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The RegexTransformer
The regex transformer helps in extracting or manipulating values from fields (from the source) using Regular
Expressions. The actual class name is org.apache.solr.handler.dataimport.RegexTransformer. But
as it belongs to the default package the package-name can be omitted.
The table below describes the attributes recognized by the regex transformer.
Attribute
regex
sourceColName
splitBy
groupNames
replaceWith
Description
The regular expression that is used to match against the column or sourceColName's
value(s). If replaceWith is absent, each regex group is taken as a value and a list of values
is returned.
The column on which the regex is to be applied. If not present, then the source and target
are identical.
Used to split a string. It returns a list of values. note: this is a regular expression – it may
need to be escaped (e.g. via back-slashes)
A comma separated list of field column names, used where the regex contains groups and
each group is to be saved to a different field. If some groups are not to be named leave a
space between commas.
Used along with regex . It is equivalent to the method new
String().replaceAll(, ).
Here is an example of configuring the regex transformer:
In this example, regex and sourceColName are custom attributes used by the transformer. The transformer
reads the field full_name from the resultset and transforms it to two new target fields, firstName and lastNa
me. Even though the query returned only one column, full_name, in the result set, the Solr document gets two
extra fields firstName and lastName which are "derived" fields. These new fields are only created if the
regexp matches.
Apache Solr Reference Guide 6.0
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