org.apache.lucene.search.suggest.document

Class SuggestField

java.lang.Object

org.apache.lucene.document.Field

org.apache.lucene.search.suggest.document.SuggestField

All Implemented Interfaces:

IndexableField

Direct Known Subclasses:

ContextSuggestField

public class SuggestField
extends Field

Field that indexes a string value and a weight as a weighted completion against a named suggester. Field is tokenized, not stored and stores documents, frequencies and positions. Field can be used to provide near real time document suggestions.

Besides the usual Analyzers, CompletionAnalyzer can be used to tune suggest field only parameters (e.g. preserving token separators, preserving position increments when converting the token stream to an automaton)

Example indexing usage:

 document.add(new SuggestField(name, "suggestion", 4));
 

To perform document suggestions based on the this field, use SuggestIndexSearcher.suggest(CompletionQuery, int, boolean)

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

Nested Class Summary

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

Field.Store

Field Summary

Fields

Modifier and Type	Field and Description
static FieldType	FIELD_TYPE Default field type for suggest field

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

fieldsData, name, tokenStream, type

Constructor Summary

Constructors

Constructor and Description
SuggestField(String name, String value, int weight) Creates a SuggestField

Method Summary

Modifier and Type	Method and Description
TokenStream	tokenStream(Analyzer analyzer, TokenStream reuse)
protected byte	type() Returns a byte to denote the type of the field
protected CompletionTokenStream	wrapTokenStream(TokenStream stream) Wraps a stream with a CompletionTokenStream.

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

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

Methods inherited from class java.lang.Object

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

Field Detail

FIELD_TYPE

public static final FieldType FIELD_TYPE

Default field type for suggest field

Constructor Detail

SuggestField

public SuggestField(String name,
                    String value,
                    int weight)

Creates a SuggestField

Parameters:

name - field name

value - field value to get suggestions on

weight - field weight

Throws:

IllegalArgumentException - if either the name or value is null, if value is an empty string, if the weight is negative, if value contains any reserved characters

Method Detail

tokenStream

public TokenStream tokenStream(Analyzer analyzer,
                               TokenStream reuse)

Specified by:

tokenStream in interface IndexableField

Overrides:

tokenStream in class Field

wrapTokenStream

protected CompletionTokenStream wrapTokenStream(TokenStream stream)

Wraps a stream with a CompletionTokenStream. Subclasses can override this method to change the indexing pipeline.

type

protected byte type()

Returns a byte to denote the type of the field