org.apache.lucene.search.suggest.analyzing

Class BlendedInfixSuggester

java.lang.Object

org.apache.lucene.search.suggest.Lookup

org.apache.lucene.search.suggest.analyzing.AnalyzingInfixSuggester

org.apache.lucene.search.suggest.analyzing.BlendedInfixSuggester

All Implemented Interfaces:

Closeable, AutoCloseable, Accountable

public class BlendedInfixSuggester
extends AnalyzingInfixSuggester

Extension of the AnalyzingInfixSuggester which transforms the weight after search to take into account the position of the searched term into the indexed text. Please note that it increases the number of elements searched and applies the ponderation after. It might be costly for long suggestions.

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

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BlendedInfixSuggester.BlenderType The different types of blender.

Nested classes/interfaces inherited from class org.apache.lucene.search.suggest.Lookup

Lookup.LookupPriorityQueue, Lookup.LookupResult

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_NUM_FACTOR Default factor
protected static double	LINEAR_COEF Coefficient used for linear blending

Fields inherited from class org.apache.lucene.search.suggest.analyzing.AnalyzingInfixSuggester

CONTEXTS_FIELD_NAME, DEFAULT_MIN_PREFIX_CHARS, EXACT_TEXT_FIELD_NAME, indexAnalyzer, queryAnalyzer, searcherMgr, TEXT_FIELD_NAME

Fields inherited from class org.apache.lucene.search.suggest.Lookup

CHARSEQUENCE_COMPARATOR

Constructor Summary

Constructors

Constructor and Description
BlendedInfixSuggester(Version matchVersion, Directory dir, Analyzer analyzer) Create a new instance, loading from a previously built directory, if it exists.
BlendedInfixSuggester(Version matchVersion, Directory dir, Analyzer indexAnalyzer, Analyzer queryAnalyzer, int minPrefixChars, BlendedInfixSuggester.BlenderType blenderType, int numFactor) Create a new instance, loading from a previously built directory, if it exists.

Method Summary

Methods

Modifier and Type	Method and Description
protected double	calculateCoefficient(int position) Calculate the weight coefficient based on the position of the first matching word.
protected List<Lookup.LookupResult>	createResults(IndexSearcher searcher, TopFieldDocs hits, int num, CharSequence key, boolean doHighlight, Set<String> matchedTokens, String prefixToken) Create the results based on the search hits.
protected FieldType	getTextFieldType() Subclass can override this method to change the field type of the text field e.g.
List<Lookup.LookupResult>	lookup(CharSequence key, Set<BytesRef> contexts, boolean onlyMorePopular, int num) Look up a key and return possible completion for this key.
List<Lookup.LookupResult>	lookup(CharSequence key, Set<BytesRef> contexts, int num, boolean allTermsRequired, boolean doHighlight) Retrieve suggestions, specifying whether all terms must match (allTermsRequired) and whether the hits should be highlighted (doHighlight).

Methods inherited from class org.apache.lucene.search.suggest.analyzing.AnalyzingInfixSuggester

add, addNonMatch, addPrefixMatch, addWholeMatch, build, close, finishQuery, getCount, getDirectory, getIndexWriterConfig, getLastTokenQuery, highlight, load, lookup, ramBytesUsed, refresh, store, update

Methods inherited from class org.apache.lucene.search.suggest.Lookup

build, load, lookup, store

Methods inherited from class java.lang.Object

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

Field Detail

LINEAR_COEF

protected static double LINEAR_COEF

Coefficient used for linear blending

DEFAULT_NUM_FACTOR

public static int DEFAULT_NUM_FACTOR

Default factor

Constructor Detail

BlendedInfixSuggester

public BlendedInfixSuggester(Version matchVersion,
                     Directory dir,
                     Analyzer analyzer)
                      throws IOException

Create a new instance, loading from a previously built directory, if it exists.

Throws:

IOException

BlendedInfixSuggester

public BlendedInfixSuggester(Version matchVersion,
                     Directory dir,
                     Analyzer indexAnalyzer,
                     Analyzer queryAnalyzer,
                     int minPrefixChars,
                     BlendedInfixSuggester.BlenderType blenderType,
                     int numFactor)
                      throws IOException

Create a new instance, loading from a previously built directory, if it exists.

Parameters:

blenderType - Type of blending strategy, see BlenderType for more precisions

numFactor - Factor to multiply the number of searched elements before ponderate

Throws:

IOException - If there are problems opening the underlying Lucene index.

Method Detail

lookup

public List<Lookup.LookupResult> lookup(CharSequence key,
                               Set<BytesRef> contexts,
                               boolean onlyMorePopular,
                               int num)
                                 throws IOException

Description copied from class: Lookup

Look up a key and return possible completion for this key.

Overrides:

lookup in class AnalyzingInfixSuggester

Parameters:

key - lookup key. Depending on the implementation this may be a prefix, misspelling, or even infix.

contexts - contexts to filter the lookup by, or null if all contexts are allowed; if the suggestion contains any of the contexts, it's a match

onlyMorePopular - return only more popular results

num - maximum number of results to return

Returns:

a list of possible completions, with their relative weight (e.g. popularity)

Throws:

IOException

lookup

public List<Lookup.LookupResult> lookup(CharSequence key,
                               Set<BytesRef> contexts,
                               int num,
                               boolean allTermsRequired,
                               boolean doHighlight)
                                 throws IOException

Description copied from class: AnalyzingInfixSuggester

Retrieve suggestions, specifying whether all terms must match (allTermsRequired) and whether the hits should be highlighted (doHighlight).

Overrides:

lookup in class AnalyzingInfixSuggester

Throws:

IOException

getTextFieldType

protected FieldType getTextFieldType()

Description copied from class: AnalyzingInfixSuggester

Subclass can override this method to change the field type of the text field e.g. to change the index options

Overrides:

getTextFieldType in class AnalyzingInfixSuggester

createResults

protected List<Lookup.LookupResult> createResults(IndexSearcher searcher,
                                      TopFieldDocs hits,
                                      int num,
                                      CharSequence key,
                                      boolean doHighlight,
                                      Set<String> matchedTokens,
                                      String prefixToken)
                                           throws IOException

Description copied from class: AnalyzingInfixSuggester

Create the results based on the search hits. Can be overridden by subclass to add particular behavior (e.g. weight transformation). Note that there is no prefix token (the prefixToken argument will be null) whenever the final token in the incoming request was in fact finished (had trailing characters, such as white-space).

Overrides:

createResults in class AnalyzingInfixSuggester

Throws:

IOException - If there are problems reading fields from the underlying Lucene index.

calculateCoefficient

protected double calculateCoefficient(int position)

Calculate the weight coefficient based on the position of the first matching word. Subclass should override it to adapt it to particular needs

Parameters:

position - of the first matching word in text

Returns:

the coefficient