org.apache.lucene.queryparser.classic

Class QueryParserBase

java.lang.Object

org.apache.lucene.util.QueryBuilder

org.apache.lucene.queryparser.classic.QueryParserBase

All Implemented Interfaces:

CommonQueryParserConfiguration

Direct Known Subclasses:

QueryParser

public abstract class QueryParserBase
extends QueryBuilder
implements CommonQueryParserConfiguration

This class is overridden by QueryParser in QueryParser.jj and acts to separate the majority of the Java code from the .jj grammar file.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) boolean	allowLeadingWildcard
static QueryParser.Operator	AND_OPERATOR Alternative form of QueryParser.Operator.AND
(package private) boolean	autoGeneratePhraseQueries
(package private) static int	CONJ_AND
(package private) static int	CONJ_NONE
(package private) static int	CONJ_OR
(package private) DateTools.Resolution	dateResolution
protected java.lang.String	field
(package private) java.util.Map<java.lang.String,DateTools.Resolution>	fieldToDateResolution
(package private) float	fuzzyMinSim
(package private) int	fuzzyPrefixLength
(package private) java.util.Locale	locale
(package private) int	maxDeterminizedStates
(package private) static int	MOD_NONE
(package private) static int	MOD_NOT
(package private) static int	MOD_REQ
(package private) MultiTermQuery.RewriteMethod	multiTermRewriteMethod
(package private) QueryParser.Operator	operator The actual operator that parser uses to combine query terms
static QueryParser.Operator	OR_OPERATOR Alternative form of QueryParser.Operator.OR
(package private) int	phraseSlop
(package private) java.util.TimeZone	timeZone
private static java.util.regex.Pattern	WILDCARD_PATTERN

Fields inherited from class org.apache.lucene.util.QueryBuilder

analyzer, autoGenerateMultiTermSynonymsPhraseQuery, enableGraphQueries, enablePositionIncrements

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	QueryParserBase()

Method Summary

Modifier and Type	Method and Description
protected void	addClause(java.util.List<BooleanClause> clauses, int conj, int mods, Query q)
protected void	addMultiTermClauses(java.util.List<BooleanClause> clauses, Query q) Adds clauses generated from analysis over text containing whitespace.
private PhraseQuery	addSlopToPhrase(PhraseQuery query, int slop) Rebuild a phrase query with a slop value
private BytesRef	analyzeWildcard(java.lang.String field, java.lang.String termStr)
(package private) java.lang.String	discardEscapeChar(java.lang.String input) Returns a String where the escape char has been removed, or kept only once if there was a double escape.
static java.lang.String	escape(java.lang.String s) Returns a String where those characters that QueryParser expects to be escaped are escaped by a preceding \.
boolean	getAllowLeadingWildcard()
boolean	getAutoGeneratePhraseQueries()
protected Query	getBooleanQuery(java.util.List<BooleanClause> clauses) Factory method for generating query, given a set of clauses.
DateTools.Resolution	getDateResolution(java.lang.String fieldName) Returns the date resolution that is used by RangeQueries for the given field.
QueryParser.Operator	getDefaultOperator() Gets implicit operator setting, which will be either AND_OPERATOR or OR_OPERATOR.
java.lang.String	getField()
protected Query	getFieldQuery(java.lang.String field, java.lang.String queryText, boolean quoted)
protected Query	getFieldQuery(java.lang.String field, java.lang.String queryText, int slop) Base implementation delegates to getFieldQuery(String,String,boolean).
float	getFuzzyMinSim() Get the minimal similarity for fuzzy queries.
int	getFuzzyPrefixLength() Get the prefix length for fuzzy queries.
protected Query	getFuzzyQuery(java.lang.String field, java.lang.String termStr, float minSimilarity) Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)).
java.util.Locale	getLocale() Returns current locale, allowing access by subclasses.
int	getMaxDeterminizedStates()
MultiTermQuery.RewriteMethod	getMultiTermRewriteMethod()
int	getPhraseSlop() Gets the default slop for phrases.
protected Query	getPrefixQuery(java.lang.String field, java.lang.String termStr) Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)).
protected Query	getRangeQuery(java.lang.String field, java.lang.String part1, java.lang.String part2, boolean startInclusive, boolean endInclusive)
protected Query	getRegexpQuery(java.lang.String field, java.lang.String termStr) Factory method for generating a query.
java.util.TimeZone	getTimeZone()
protected Query	getWildcardQuery(java.lang.String field, java.lang.String termStr) Factory method for generating a query.
(package private) Query	handleBareFuzzy(java.lang.String qfield, Token fuzzySlop, java.lang.String termImage)
(package private) Query	handleBareTokenQuery(java.lang.String qfield, Token term, Token fuzzySlop, boolean prefix, boolean wildcard, boolean fuzzy, boolean regexp)
(package private) Query	handleBoost(Query q, Token boost)
(package private) Query	handleQuotedTerm(java.lang.String qfield, Token term, Token fuzzySlop)
(package private) static int	hexToInt(char c) Returns the numeric value of the hexadecimal character
void	init(java.lang.String f, Analyzer a) Initializes a query parser.
protected BooleanClause	newBooleanClause(Query q, BooleanClause.Occur occur) Builds a new BooleanClause instance
protected Query	newFieldQuery(Analyzer analyzer, java.lang.String field, java.lang.String queryText, boolean quoted)
protected Query	newFuzzyQuery(Term term, float minimumSimilarity, int prefixLength) Builds a new FuzzyQuery instance
protected Query	newMatchAllDocsQuery() Builds a new MatchAllDocsQuery instance
protected Query	newPrefixQuery(Term prefix) Builds a new PrefixQuery instance
protected Query	newRangeQuery(java.lang.String field, java.lang.String part1, java.lang.String part2, boolean startInclusive, boolean endInclusive) Builds a new TermRangeQuery instance
protected Query	newRegexpQuery(Term regexp) Builds a new RegexpQuery instance
protected Query	newWildcardQuery(Term t) Builds a new WildcardQuery instance
Query	parse(java.lang.String query) Parses a query string, returning a Query.
abstract void	ReInit(CharStream stream)
void	setAllowLeadingWildcard(boolean allowLeadingWildcard) Set to true to allow leading wildcard characters.
void	setAutoGeneratePhraseQueries(boolean value) Set to true if phrase queries will be automatically generated when the analyzer returns more than one term from whitespace delimited text.
void	setDateResolution(DateTools.Resolution dateResolution) Sets the default date resolution used by RangeQueries for fields for which no specific date resolutions has been set.
void	setDateResolution(java.lang.String fieldName, DateTools.Resolution dateResolution) Sets the date resolution used by RangeQueries for a specific field.
void	setDefaultOperator(QueryParser.Operator op) Sets the boolean operator of the QueryParser.
void	setFuzzyMinSim(float fuzzyMinSim) Set the minimum similarity for fuzzy queries.
void	setFuzzyPrefixLength(int fuzzyPrefixLength) Set the prefix length for fuzzy queries.
void	setLocale(java.util.Locale locale) Set locale used by date range parsing, lowercasing, and other locale-sensitive operations.
void	setMaxDeterminizedStates(int maxDeterminizedStates)
void	setMultiTermRewriteMethod(MultiTermQuery.RewriteMethod method) By default QueryParser uses MultiTermQuery.CONSTANT_SCORE_REWRITE when creating a PrefixQuery, WildcardQuery or TermRangeQuery.
void	setPhraseSlop(int phraseSlop) Sets the default slop for phrases.
void	setTimeZone(java.util.TimeZone timeZone)
abstract Query	TopLevelQuery(java.lang.String field)

Methods inherited from class org.apache.lucene.util.QueryBuilder

add, analyzeBoolean, analyzeGraphBoolean, analyzeGraphPhrase, analyzeMultiBoolean, analyzeMultiPhrase, analyzePhrase, analyzeTerm, createBooleanQuery, createBooleanQuery, createFieldQuery, createFieldQuery, createMinShouldMatchQuery, createPhraseQuery, createPhraseQuery, createSpanQuery, getAnalyzer, getAutoGenerateMultiTermSynonymsPhraseQuery, getEnableGraphQueries, getEnablePositionIncrements, newBooleanQuery, newGraphSynonymQuery, newMultiPhraseQueryBuilder, newSynonymQuery, newTermQuery, setAnalyzer, setAutoGenerateMultiTermSynonymsPhraseQuery, setEnableGraphQueries, setEnablePositionIncrements

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.queryparser.flexible.standard.CommonQueryParserConfiguration

getAnalyzer, getEnablePositionIncrements, setEnablePositionIncrements

Field Detail

CONJ_NONE

static final int CONJ_NONE

See Also:

Constant Field Values

CONJ_AND

static final int CONJ_AND

See Also:

Constant Field Values

CONJ_OR

static final int CONJ_OR

See Also:

Constant Field Values

MOD_NONE

static final int MOD_NONE

See Also:

Constant Field Values

MOD_NOT

static final int MOD_NOT

See Also:

Constant Field Values

MOD_REQ

static final int MOD_REQ

See Also:

Constant Field Values

AND_OPERATOR

public static final QueryParser.Operator AND_OPERATOR

Alternative form of QueryParser.Operator.AND

OR_OPERATOR

public static final QueryParser.Operator OR_OPERATOR

Alternative form of QueryParser.Operator.OR

operator

QueryParser.Operator operator

The actual operator that parser uses to combine query terms

multiTermRewriteMethod

MultiTermQuery.RewriteMethod multiTermRewriteMethod

allowLeadingWildcard

boolean allowLeadingWildcard

field

protected java.lang.String field

phraseSlop

int phraseSlop

fuzzyMinSim

float fuzzyMinSim

fuzzyPrefixLength

int fuzzyPrefixLength

locale

java.util.Locale locale

timeZone

java.util.TimeZone timeZone

dateResolution

DateTools.Resolution dateResolution

fieldToDateResolution

java.util.Map<java.lang.String,DateTools.Resolution> fieldToDateResolution

autoGeneratePhraseQueries

boolean autoGeneratePhraseQueries

maxDeterminizedStates

int maxDeterminizedStates

WILDCARD_PATTERN

private static final java.util.regex.Pattern WILDCARD_PATTERN

Constructor Detail

QueryParserBase

protected QueryParserBase()

Method Detail

init

public void init(java.lang.String f,
                 Analyzer a)

Initializes a query parser. Called by the QueryParser constructor

Parameters:

f - the default field for query terms.

a - used to find terms in the query text.

ReInit

public abstract void ReInit(CharStream stream)

TopLevelQuery

public abstract Query TopLevelQuery(java.lang.String field)
                             throws ParseException

Throws:

ParseException

parse

public Query parse(java.lang.String query)
            throws ParseException

Parses a query string, returning a Query.

Parameters:

query - the query string to be parsed.

Throws:

ParseException - if the parsing fails

getField

public java.lang.String getField()

Returns:

Returns the default field.

getAutoGeneratePhraseQueries

public final boolean getAutoGeneratePhraseQueries()

See Also:

setAutoGeneratePhraseQueries(boolean)

setAutoGeneratePhraseQueries

public void setAutoGeneratePhraseQueries(boolean value)

Set to true if phrase queries will be automatically generated when the analyzer returns more than one term from whitespace delimited text. NOTE: this behavior may not be suitable for all languages.

Set to false if phrase queries should only be generated when surrounded by double quotes.

getFuzzyMinSim

public float getFuzzyMinSim()

Get the minimal similarity for fuzzy queries.

Specified by:

getFuzzyMinSim in interface CommonQueryParserConfiguration

setFuzzyMinSim

public void setFuzzyMinSim(float fuzzyMinSim)

Set the minimum similarity for fuzzy queries. Default is 2f.

Specified by:

setFuzzyMinSim in interface CommonQueryParserConfiguration

getFuzzyPrefixLength

public int getFuzzyPrefixLength()

Get the prefix length for fuzzy queries.

Specified by:

getFuzzyPrefixLength in interface CommonQueryParserConfiguration

Returns:

Returns the fuzzyPrefixLength.

setFuzzyPrefixLength

public void setFuzzyPrefixLength(int fuzzyPrefixLength)

Set the prefix length for fuzzy queries. Default is 0.

Specified by:

setFuzzyPrefixLength in interface CommonQueryParserConfiguration

Parameters:

fuzzyPrefixLength - The fuzzyPrefixLength to set.

setPhraseSlop

public void setPhraseSlop(int phraseSlop)

Sets the default slop for phrases. If zero, then exact phrase matches are required. Default value is zero.

Specified by:

setPhraseSlop in interface CommonQueryParserConfiguration

getPhraseSlop

public int getPhraseSlop()

Gets the default slop for phrases.

Specified by:

getPhraseSlop in interface CommonQueryParserConfiguration

setAllowLeadingWildcard

public void setAllowLeadingWildcard(boolean allowLeadingWildcard)

Set to true to allow leading wildcard characters.

When set, * or ? are allowed as the first character of a PrefixQuery and WildcardQuery. Note that this can produce very slow queries on big indexes.

Default: false.

Specified by:

setAllowLeadingWildcard in interface CommonQueryParserConfiguration

getAllowLeadingWildcard

public boolean getAllowLeadingWildcard()

Specified by:

getAllowLeadingWildcard in interface CommonQueryParserConfiguration

See Also:

setAllowLeadingWildcard(boolean)

setDefaultOperator

public void setDefaultOperator(QueryParser.Operator op)

Sets the boolean operator of the QueryParser. In default mode (OR_OPERATOR) terms without any modifiers are considered optional: for example capital of Hungary is equal to capital OR of OR Hungary.
In AND_OPERATOR mode terms are considered to be in conjunction: the above mentioned query is parsed as capital AND of AND Hungary

getDefaultOperator

public QueryParser.Operator getDefaultOperator()

Gets implicit operator setting, which will be either AND_OPERATOR or OR_OPERATOR.

setMultiTermRewriteMethod

public void setMultiTermRewriteMethod(MultiTermQuery.RewriteMethod method)

By default QueryParser uses MultiTermQuery.CONSTANT_SCORE_REWRITE when creating a PrefixQuery, WildcardQuery or TermRangeQuery. This implementation is generally preferable because it a) Runs faster b) Does not have the scarcity of terms unduly influence score c) avoids any BooleanQuery.TooManyClauses exception. However, if your application really needs to use the old-fashioned BooleanQuery expansion rewriting and the above points are not relevant then use this to change the rewrite method.

Specified by:

setMultiTermRewriteMethod in interface CommonQueryParserConfiguration

getMultiTermRewriteMethod

public MultiTermQuery.RewriteMethod getMultiTermRewriteMethod()

Specified by:

getMultiTermRewriteMethod in interface CommonQueryParserConfiguration

See Also:

setMultiTermRewriteMethod(org.apache.lucene.search.MultiTermQuery.RewriteMethod)

setLocale

public void setLocale(java.util.Locale locale)

Set locale used by date range parsing, lowercasing, and other locale-sensitive operations.

Specified by:

setLocale in interface CommonQueryParserConfiguration

getLocale

public java.util.Locale getLocale()

Returns current locale, allowing access by subclasses.

Specified by:

getLocale in interface CommonQueryParserConfiguration

setTimeZone

public void setTimeZone(java.util.TimeZone timeZone)

Specified by:

setTimeZone in interface CommonQueryParserConfiguration

getTimeZone

public java.util.TimeZone getTimeZone()

Specified by:

getTimeZone in interface CommonQueryParserConfiguration

setDateResolution

public void setDateResolution(DateTools.Resolution dateResolution)

Sets the default date resolution used by RangeQueries for fields for which no specific date resolutions has been set. Field specific resolutions can be set with setDateResolution(String, org.apache.lucene.document.DateTools.Resolution).

Specified by:

setDateResolution in interface CommonQueryParserConfiguration

Parameters:

dateResolution - the default date resolution to set

setDateResolution

public void setDateResolution(java.lang.String fieldName,
                              DateTools.Resolution dateResolution)

Sets the date resolution used by RangeQueries for a specific field.

Parameters:

fieldName - field for which the date resolution is to be set

dateResolution - date resolution to set

getDateResolution

public DateTools.Resolution getDateResolution(java.lang.String fieldName)

Returns the date resolution that is used by RangeQueries for the given field. Returns null, if no default or field specific date resolution has been set for the given field.

setMaxDeterminizedStates

public void setMaxDeterminizedStates(int maxDeterminizedStates)

Parameters:

maxDeterminizedStates - the maximum number of states that determinizing a regexp query can result in. If the query results in any more states a TooComplexToDeterminizeException is thrown.

getMaxDeterminizedStates

public int getMaxDeterminizedStates()

Returns:

the maximum number of states that determinizing a regexp query can result in. If the query results in any more states a TooComplexToDeterminizeException is thrown.

addClause

protected void addClause(java.util.List<BooleanClause> clauses,
                         int conj,
                         int mods,
                         Query q)

addMultiTermClauses

protected void addMultiTermClauses(java.util.List<BooleanClause> clauses,
                                   Query q)

Adds clauses generated from analysis over text containing whitespace. There are no operators, so the query's clauses can either be MUST (if the default operator is AND) or SHOULD (default OR). If all of the clauses in the given Query are TermQuery-s, this method flattens the result by adding the TermQuery-s individually to the output clause list; otherwise, the given Query is added as a single clause including its nested clauses.

getFieldQuery

protected Query getFieldQuery(java.lang.String field,
                              java.lang.String queryText,
                              boolean quoted)
                       throws ParseException

Throws:

ParseException - throw in overridden method to disallow

newFieldQuery

protected Query newFieldQuery(Analyzer analyzer,
                              java.lang.String field,
                              java.lang.String queryText,
                              boolean quoted)
                       throws ParseException

Throws:

ParseException - throw in overridden method to disallow

getFieldQuery

protected Query getFieldQuery(java.lang.String field,
                              java.lang.String queryText,
                              int slop)
                       throws ParseException

Base implementation delegates to getFieldQuery(String,String,boolean). This method may be overridden, for example, to return a SpanNearQuery instead of a PhraseQuery.

Throws:

ParseException - throw in overridden method to disallow

addSlopToPhrase

private PhraseQuery addSlopToPhrase(PhraseQuery query,
                                    int slop)

Rebuild a phrase query with a slop value

getRangeQuery

protected Query getRangeQuery(java.lang.String field,
                              java.lang.String part1,
                              java.lang.String part2,
                              boolean startInclusive,
                              boolean endInclusive)
                       throws ParseException

Throws:

ParseException

newBooleanClause

protected BooleanClause newBooleanClause(Query q,
                                         BooleanClause.Occur occur)

Builds a new BooleanClause instance

Parameters:

q - sub query

occur - how this clause should occur when matching documents

Returns:

new BooleanClause instance

newPrefixQuery

protected Query newPrefixQuery(Term prefix)

Builds a new PrefixQuery instance

Parameters:

prefix - Prefix term

Returns:

new PrefixQuery instance

newRegexpQuery

protected Query newRegexpQuery(Term regexp)

Builds a new RegexpQuery instance

Parameters:

regexp - Regexp term

Returns:

new RegexpQuery instance

newFuzzyQuery

protected Query newFuzzyQuery(Term term,
                              float minimumSimilarity,
                              int prefixLength)

Builds a new FuzzyQuery instance

Parameters:

term - Term

minimumSimilarity - minimum similarity

prefixLength - prefix length

Returns:

new FuzzyQuery Instance

newRangeQuery

protected Query newRangeQuery(java.lang.String field,
                              java.lang.String part1,
                              java.lang.String part2,
                              boolean startInclusive,
                              boolean endInclusive)

Builds a new TermRangeQuery instance

Parameters:

field - Field

part1 - min

part2 - max

startInclusive - true if the start of the range is inclusive

endInclusive - true if the end of the range is inclusive

Returns:

new TermRangeQuery instance

newMatchAllDocsQuery

protected Query newMatchAllDocsQuery()

Builds a new MatchAllDocsQuery instance

Returns:

new MatchAllDocsQuery instance

newWildcardQuery

protected Query newWildcardQuery(Term t)

Builds a new WildcardQuery instance

Parameters:

t - wildcard term

Returns:

new WildcardQuery instance

getBooleanQuery

protected Query getBooleanQuery(java.util.List<BooleanClause> clauses)
                         throws ParseException

Factory method for generating query, given a set of clauses. By default creates a boolean query composed of clauses passed in. Can be overridden by extending classes, to modify query being returned.

Parameters:

clauses - List that contains BooleanClause instances to join.

Returns:

Resulting Query object.

Throws:

ParseException - throw in overridden method to disallow

getWildcardQuery

protected Query getWildcardQuery(java.lang.String field,
                                 java.lang.String termStr)
                          throws ParseException

Factory method for generating a query. 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 settings, prefix term may be lower-cased automatically. It will not go through the default Analyzer, however, since normal Analyzers are unlikely to work properly with wildcard templates.

Can be overridden by extending classes, to provide custom handling for wildcard queries, which may be necessary due to missing analyzer calls.

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 - throw in overridden method to disallow

analyzeWildcard

private BytesRef analyzeWildcard(java.lang.String field,
                                 java.lang.String termStr)

getRegexpQuery

protected Query getRegexpQuery(java.lang.String field,
                               java.lang.String termStr)
                        throws ParseException

Factory method for generating a query. Called when parser parses an input term token that contains a regular expression query.

Depending on settings, pattern term may be lower-cased automatically. It will not go through the default Analyzer, however, since normal Analyzers are unlikely to work properly with regular expression templates.

Can be overridden by extending classes, to provide custom handling for regular expression queries, which may be necessary due to missing analyzer calls.

Parameters:

field - Name of the field query will use.

termStr - Term token that contains a regular expression

Returns:

Resulting Query built for the term

Throws:

ParseException - throw in overridden method to disallow

getPrefixQuery

protected Query getPrefixQuery(java.lang.String field,
                               java.lang.String termStr)
                        throws ParseException

Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)). 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 settings, a prefix term may be lower-cased automatically. It will not go through the default Analyzer, however, since normal Analyzers are unlikely to work properly with wildcard templates.

Can be overridden by extending classes, to provide custom handling for wild card queries, which may be necessary due to missing analyzer calls.

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 - throw in overridden method to disallow

getFuzzyQuery

protected Query getFuzzyQuery(java.lang.String field,
                              java.lang.String termStr,
                              float minSimilarity)
                       throws ParseException

Factory method for generating a query (similar to getWildcardQuery(java.lang.String, java.lang.String)). Called when parser parses an input term token that has the fuzzy suffix (~) appended.

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 - throw in overridden method to disallow

handleBareTokenQuery

Query handleBareTokenQuery(java.lang.String qfield,
                           Token term,
                           Token fuzzySlop,
                           boolean prefix,
                           boolean wildcard,
                           boolean fuzzy,
                           boolean regexp)
                    throws ParseException

Throws:

ParseException

handleBareFuzzy

Query handleBareFuzzy(java.lang.String qfield,
                      Token fuzzySlop,
                      java.lang.String termImage)
               throws ParseException

Throws:

ParseException

handleQuotedTerm

Query handleQuotedTerm(java.lang.String qfield,
                       Token term,
                       Token fuzzySlop)
                throws ParseException

Throws:

ParseException

handleBoost

Query handleBoost(Query q,
                  Token boost)

discardEscapeChar

java.lang.String discardEscapeChar(java.lang.String input)
                            throws ParseException

Returns a String where the escape char has been removed, or kept only once if there was a double escape. Supports escaped unicode characters, e. g. translates \\u0041 to A.

Throws:

ParseException

hexToInt

static final int hexToInt(char c)
                   throws ParseException

Returns the numeric value of the hexadecimal character

Throws:

ParseException

escape

public static java.lang.String escape(java.lang.String s)

Returns a String where those characters that QueryParser expects to be escaped are escaped by a preceding \.