org.apache.lucene.queryParser.analyzing

Class AnalyzingQueryParser

Implemented Interfaces:
QueryParserConstants

public class AnalyzingQueryParser
extends QueryParser

Overrides Lucene's default QueryParser so that Fuzzy-, Prefix-, Range-, and WildcardQuerys are also passed through the given analyzer, but ? and * don't get removed from the search terms.

Warning: This class should only be used with analyzers that do not use stopwords or that add tokens. Also, several stemming analyzers are inappropriate: for example, GermanAnalyzer will turn Häuser into hau, but H?user will become h?user when using this parser and thus no match would be found (i.e. using this parser will be no improvement over QueryParser in such cases).

Version:
$Revision$, $Date$
Author:
Ronnie Kolehmainen (ronnie.kolehmainen at ub.uu.se)

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.queryParser.QueryParser

QueryParser.Operator

Field Summary

Fields inherited from class org.apache.lucene.queryParser.QueryParser

AND_OPERATOR, OR_OPERATOR, jj_nt, lookingAhead, token, token_source

Fields inherited from interface org.apache.lucene.queryParser.QueryParserConstants

AND, Boost, CARAT, COLON, DEFAULT, EOF, FUZZY_SLOP, LPAREN, MINUS, NOT, NUMBER, OR, PLUS, PREFIXTERM, QUOTED, RANGEEX_END, RANGEEX_GOOP, RANGEEX_QUOTED, RANGEEX_START, RANGEEX_TO, RANGEIN_END, RANGEIN_GOOP, RANGEIN_QUOTED, RANGEIN_START, RANGEIN_TO, RPAREN, RangeEx, RangeIn, STAR, TERM, WILDTERM, _ESCAPED_CHAR, _NUM_CHAR, _TERM_CHAR, _TERM_START_CHAR, _WHITESPACE, tokenImage

Constructor Summary

AnalyzingQueryParser(String field, Analyzer analyzer)
Constructs a query parser.

Method Summary

protected Query
getFuzzyQuery(String field, String termStr, float minSimilarity)
Called when parser parses an input term token that has the fuzzy suffix (~) appended.
protected Query
getPrefixQuery(String field, String termStr)
Called when parser parses an input term token that uses prefix notation; that is, contains a single '*' wildcard character as its last character.
protected Query
getRangeQuery(String field, String part1, String part2, boolean inclusive)
Overrides super class, by passing terms through analyzer.
protected Query
getWildcardQuery(String field, String termStr)
Called when parser parses an input term token that contains one or more wildcard characters (? and *), but is not a prefix term token (one that has just a single * character at the end)

Depending on analyzer and settings, a wildcard term may (most probably will) be lower-cased automatically.

Methods inherited from class org.apache.lucene.queryParser.QueryParser

Clause, Conjunction, Modifiers, Query, ReInit, ReInit, Term, addClause, disable_tracing, enable_tracing, escape, generateParseException, getAllowLeadingWildcard, getAnalyzer, getBooleanQuery, getBooleanQuery, getDateResolution, getDefaultOperator, getField, getFieldQuery, getFieldQuery, getFuzzyMinSim, getFuzzyPrefixLength, getFuzzyQuery, getLocale, getLowercaseExpandedTerms, getNextToken, getPhraseSlop, getPrefixQuery, getRangeQuery, getToken, getUseOldRangeQuery, getWildcardQuery, main, parse, setAllowLeadingWildcard, setDateResolution, setDateResolution, setDefaultOperator, setFuzzyMinSim, setFuzzyPrefixLength, setLocale, setLowercaseExpandedTerms, setPhraseSlop, setUseOldRangeQuery

Constructor Details

AnalyzingQueryParser

public AnalyzingQueryParser(String field,
                            Analyzer analyzer)
Constructs a query parser.
Parameters:
field - the default field for query terms.
analyzer - used to find terms in the query text.

Method Details

getFuzzyQuery

protected Query getFuzzyQuery(String field,
                              String termStr,
                              float minSimilarity)
            throws ParseException
Called when parser parses an input term token that has the fuzzy suffix (~) appended.

Depending on analyzer and settings, a fuzzy term may (most probably will) be lower-cased automatically. It will go through the default Analyzer.

Overrides super class, by passing terms through analyzer.

Overrides:
getFuzzyQuery in interface QueryParser
Parameters:
field - Name of the field query will use.
termStr - Term token to use for building term for the query
Returns:
Resulting Query built for the term
Throws:
ParseException -

getPrefixQuery

protected Query getPrefixQuery(String field,
                               String termStr)
            throws ParseException
Called when parser parses an input term token that uses prefix notation; that is, contains a single '*' wildcard character as its last character. Since this is a special case of generic wildcard term, and such a query can be optimized easily, this usually results in a different query object.

Depending on analyzer and settings, a prefix term may (most probably will) be lower-cased automatically. It will go through the default Analyzer.

Overrides super class, by passing terms through analyzer.

Overrides:
getPrefixQuery in interface QueryParser
Parameters:
field - Name of the field query will use.
termStr - Term token to use for building term for the query (without trailing '*' character!)
Returns:
Resulting Query built for the term
Throws:
ParseException -

getRangeQuery

protected Query getRangeQuery(String field,
                              String part1,
                              String part2,
                              boolean inclusive)
            throws ParseException
Overrides super class, by passing terms through analyzer.
Overrides:
getRangeQuery in interface QueryParser
Throws:
ParseException -

getWildcardQuery

protected Query getWildcardQuery(String field,
                                 String termStr)
            throws ParseException
Called when parser parses an input term token that contains one or more wildcard characters (? and *), but is not a prefix term token (one that has just a single * character at the end)

Depending on analyzer and settings, a wildcard term may (most probably will) be lower-cased automatically. It will go through the default Analyzer.

Overrides super class, by passing terms through analyzer.

Overrides:
getWildcardQuery in interface QueryParser
Parameters:
field - Name of the field query will use.
termStr - Term token that contains one or more wild card characters (? or *), but is not simple prefix term
Returns:
Resulting Query built for the term
Throws:
ParseException -

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