org.apache.solr.update.processor

Class CountFieldValuesUpdateProcessorFactory

java.lang.Object

org.apache.solr.update.processor.UpdateRequestProcessorFactory

org.apache.solr.update.processor.FieldMutatingUpdateProcessorFactory

org.apache.solr.update.processor.CountFieldValuesUpdateProcessorFactory

All Implemented Interfaces:

NamedListInitializedPlugin, SolrCoreAware

public final class CountFieldValuesUpdateProcessorFactory
extends FieldMutatingUpdateProcessorFactory

Replaces any list of values for a field matching the specified conditions with the the count of the number of values for that field.

By default, this processor matches no fields.

The typical use case for this processor would be in combination with the CloneFieldUpdateProcessorFactory so that it's possible to query by the quantity of values in the source field.

For example, in the configuration below, the end result will be that the category_count field can be used to search for documents based on how many values they contain in the category field.

 <processor class="solr.CloneFieldUpdateProcessorFactory">
   <str name="source">category</str>
   <str name="dest">category_count</str>
 </processor>
 <processor class="solr.CountFieldValuesUpdateProcessorFactory">
   <str name="fieldName">category_count</str>
 </processor>
 <processor class="solr.DefaultValueUpdateProcessorFactory">
   <str name="fieldName">category_count</str>
   <int name="value">0</int>
 </processor>

NOTE: The use of DefaultValueUpdateProcessorFactory is important in this example to ensure that all documents have a value for the category_count field, because CountFieldValuesUpdateProcessorFactory only replaces the list of values with the size of that list. If DefaultValueUpdateProcessorFactory was not used, then any document that had no values for the category field, would also have no value in the category_count field.

Since:

4.0.0

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.solr.update.processor.FieldMutatingUpdateProcessorFactory

FieldMutatingUpdateProcessorFactory.SelectorParams

Nested classes/interfaces inherited from class org.apache.solr.update.processor.UpdateRequestProcessorFactory

UpdateRequestProcessorFactory.RunAlways

Constructor Summary

Constructors

Constructor and Description
CountFieldValuesUpdateProcessorFactory()

Method Summary

Modifier and Type	Method and Description
UpdateRequestProcessor	getInstance(SolrQueryRequest req, SolrQueryResponse rsp, UpdateRequestProcessor next)

Methods inherited from class org.apache.solr.update.processor.FieldMutatingUpdateProcessorFactory

getDefaultSelector, getSelector, inform, init, parseSelectorExclusionParams, parseSelectorParams

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CountFieldValuesUpdateProcessorFactory

public CountFieldValuesUpdateProcessorFactory()

Method Detail

getInstance

public UpdateRequestProcessor getInstance(SolrQueryRequest req,
                                          SolrQueryResponse rsp,
                                          UpdateRequestProcessor next)

Specified by:

getInstance in class UpdateRequestProcessorFactory