org.apache.lucene.facet

Class DrillDownQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.facet.DrillDownQuery

public final class DrillDownQuery
extends Query

A Query for drill-down over facet categories. You should call add(String, String...) for every group of categories you want to drill-down over.

NOTE: if you choose to create your own Query by calling term(java.lang.String, java.lang.String, java.lang.String...), it is recommended to wrap it in a BoostQuery with a boost of 0.0f, so that it does not affect the scores of the documents.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary

Constructors

Constructor and Description
DrillDownQuery(FacetsConfig config) Creates a new DrillDownQuery without a base query, to perform a pure browsing query (equivalent to using MatchAllDocsQuery as base).
DrillDownQuery(FacetsConfig config, Query baseQuery) Creates a new DrillDownQuery over the given base query.

Method Summary

Modifier and Type	Method and Description
void	add(String dim, Query subQuery) Expert: add a custom drill-down subQuery.
void	add(String dim, String... path) Adds one dimension of drill downs; if you pass the same dimension more than once it is OR'd with the previous constraints on that dimension, and all dimensions are AND'd against each other and the base query.
DrillDownQuery	clone()
boolean	equals(Object other)
int	hashCode()
Query	rewrite(IndexReader r)
static Term	term(String field, String dim, String... path) Creates a drill-down term.
String	toString(String field)
void	visit(QueryVisitor visitor)

Methods inherited from class org.apache.lucene.search.Query

classHash, createWeight, sameClassAs, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DrillDownQuery

public DrillDownQuery(FacetsConfig config)

Creates a new DrillDownQuery without a base query, to perform a pure browsing query (equivalent to using MatchAllDocsQuery as base).

DrillDownQuery

public DrillDownQuery(FacetsConfig config,
                      Query baseQuery)

Creates a new DrillDownQuery over the given base query. Can be null, in which case the result Query from rewrite(IndexReader) will be a pure browsing query, filtering on the added categories only.

Method Detail

term

public static Term term(String field,
                        String dim,
                        String... path)

Creates a drill-down term.

add

public void add(String dim,
                String... path)

Adds one dimension of drill downs; if you pass the same dimension more than once it is OR'd with the previous constraints on that dimension, and all dimensions are AND'd against each other and the base query.

add

public void add(String dim,
                Query subQuery)

Expert: add a custom drill-down subQuery. Use this when you have a separate way to drill-down on the dimension than the indexed facet ordinals.

clone

public DrillDownQuery clone()

Overrides:

clone in class Object

hashCode

public int hashCode()

Specified by:

hashCode in class Query

equals

public boolean equals(Object other)

Specified by:

equals in class Query

rewrite

public Query rewrite(IndexReader r)
              throws IOException

Overrides:

rewrite in class Query

Throws:

IOException

toString

public String toString(String field)

Specified by:

toString in class Query

visit

public void visit(QueryVisitor visitor)

Overrides:

visit in class Query