Package org.apache.lucene.document

Class KeywordField

java.lang.Object

org.apache.lucene.document.Field

org.apache.lucene.document.KeywordField

All Implemented Interfaces:

IndexableField

public class KeywordField
extends Field

Field that indexes a per-document String or BytesRef into an inverted index for fast filtering, stores values in a columnar fashion using DocValuesType.SORTED_SET doc values for sorting and faceting, and optionally stores values as stored fields for top-hits retrieval. This field does not support scoring: queries produce constant scores. If you need more fine-grained control you can use StringField, SortedDocValuesField or SortedSetDocValuesField, and StoredField.

This field defines static factory methods for creating common query objects:

• newExactQuery(java.lang.String, org.apache.lucene.util.BytesRef) for matching a value.
• newSetQuery(java.lang.String, org.apache.lucene.util.BytesRef...) for matching any of the values coming from a set.
• newSortField(java.lang.String, boolean, org.apache.lucene.search.SortedSetSelector.Type) for matching a value.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.document.Field

Field.Store

Field Summary

Fields inherited from class org.apache.lucene.document.Field

fieldsData, name, tokenStream, type

Constructor Summary

Constructors

Constructor	Description
KeywordField(String name, String value, Field.Store stored)	Creates a new KeywordField from a String value, by indexing its UTF-8 representation.
KeywordField(String name, BytesRef value, Field.Store stored)	Creates a new KeywordField.

Method Summary

Modifier and Type	Method	Description
BytesRef	binaryValue()	Non-null if this field has a binary value
InvertableType	invertableType()	Describes how this field should be inverted.
static Query	newExactQuery(String field, String value)	Create a query for matching an exact String value.
static Query	newExactQuery(String field, BytesRef value)	Create a query for matching an exact BytesRef value.
static Query	newSetQuery(String field, BytesRef... values)	Create a query for matching any of a set of provided BytesRef values.
static SortField	newSortField(String field, boolean reverse, SortedSetSelector.Type selector)	Create a new SortField for BytesRef values.
void	setBytesValue(BytesRef value)	Expert: change the value of this field.
void	setStringValue(String value)	Expert: change the value of this field.
StoredValue	storedValue()	Stored value.

Methods inherited from class org.apache.lucene.document.Field

fieldType, getCharSequenceValue, name, numericValue, readerValue, setBytesValue, setByteValue, setDoubleValue, setFloatValue, setIntValue, setLongValue, setReaderValue, setShortValue, setTokenStream, stringValue, tokenStream, tokenStreamValue, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

KeywordField

public KeywordField(String name,
                    BytesRef value,
                    Field.Store stored)

Creates a new KeywordField.

Parameters:

name - field name

value - the BytesRef value

stored - whether to store the field

Throws:

IllegalArgumentException - if the field name or value is null.

KeywordField

public KeywordField(String name,
                    String value,
                    Field.Store stored)

Creates a new KeywordField from a String value, by indexing its UTF-8 representation.

Parameters:

name - field name

value - the BytesRef value

stored - whether to store the field

Throws:

IllegalArgumentException - if the field name or value is null.

Method Detail

binaryValue

public BytesRef binaryValue()

Description copied from interface: IndexableField

Non-null if this field has a binary value

Specified by:

binaryValue in interface IndexableField

Overrides:

binaryValue in class Field

invertableType

public InvertableType invertableType()

Description copied from interface: IndexableField

Describes how this field should be inverted. This must return a non-null value if the field indexes terms and postings.

Specified by:

invertableType in interface IndexableField

Overrides:

invertableType in class Field

setStringValue

public void setStringValue(String value)

Description copied from class: Field

Expert: change the value of this field. This can be used during indexing to re-use a single Field instance to improve indexing speed by avoiding GC cost of new'ing and reclaiming Field instances. Typically a single Document instance is re-used as well. This helps most on small documents.

Each Field instance should only be used once within a single Document instance. See ImproveIndexingSpeed for details.

Overrides:

setStringValue in class Field

setBytesValue

public void setBytesValue(BytesRef value)

Description copied from class: Field

Expert: change the value of this field. See Field.setStringValue(String).

NOTE: the provided BytesRef is not copied so be sure not to change it until you're done with this field.

Overrides:

setBytesValue in class Field

storedValue

public StoredValue storedValue()

Description copied from interface: IndexableField

Stored value. This method is called to populate stored fields and must return a non-null value if the field stored.

Specified by:

storedValue in interface IndexableField

Overrides:

storedValue in class Field

newExactQuery

public static Query newExactQuery(String field,
                                  BytesRef value)

Create a query for matching an exact BytesRef value.

Parameters:

field - field name. must not be null.

value - exact value

Returns:

a query matching documents with this exact value

Throws:

NullPointerException - if field is null.

newExactQuery

public static Query newExactQuery(String field,
                                  String value)

Create a query for matching an exact String value.

Parameters:

field - field name. must not be null.

value - exact value

Returns:

a query matching documents with this exact value

Throws:

NullPointerException - if field is null.

newSetQuery

public static Query newSetQuery(String field,
                                BytesRef... values)

Create a query for matching any of a set of provided BytesRef values.

Parameters:

field - field name. must not be null.

values - the set of values to match

Returns:

a query matching documents with this exact value

Throws:

NullPointerException - if field is null.

newSortField

public static SortField newSortField(String field,
                                     boolean reverse,
                                     SortedSetSelector.Type selector)

Create a new SortField for BytesRef values.

Parameters:

field - field name. must not be null.

reverse - true if natural order should be reversed.

selector - custom selector type for choosing the sort value from the set.