org.apache.lucene.queryParser

Class MultiFieldQueryParser

java.lang.Object

org.apache.lucene.queryParser.QueryParser

org.apache.lucene.queryParser.MultiFieldQueryParser

All Implemented Interfaces:

QueryParserConstants

public class MultiFieldQueryParser
extends QueryParser

A QueryParser which constructs queries to search multiple fields.

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, jj_nt, lookingAhead, OR_OPERATOR, token, token_source

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

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

Constructor Summary

Constructors

Constructor and Description
MultiFieldQueryParser(java.lang.String[] fields, Analyzer analyzer) Creates a MultiFieldQueryParser.
MultiFieldQueryParser(java.lang.String[] fields, Analyzer analyzer, java.util.Map boosts) Creates a MultiFieldQueryParser.

Method Summary

Modifier and Type	Method and Description
static Query	parse(java.lang.String[] queries, java.lang.String[] fields, Analyzer analyzer) Parses a query which searches on the fields specified.
static Query	parse(java.lang.String[] queries, java.lang.String[] fields, BooleanClause.Occur[] flags, Analyzer analyzer) Parses a query, searching on the fields specified.
static Query	parse(java.lang.String query, java.lang.String[] fields, BooleanClause.Occur[] flags, Analyzer analyzer) Parses a query, searching on the fields specified.

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

Clause, Conjunction, disable_tracing, enable_tracing, escape, generateParseException, getAllowLeadingWildcard, getAnalyzer, getDateResolution, getDefaultOperator, getEnablePositionIncrements, getField, getFuzzyMinSim, getFuzzyPrefixLength, getLocale, getLowercaseExpandedTerms, getNextToken, getPhraseSlop, getToken, getUseOldRangeQuery, main, Modifiers, parse, Query, ReInit, ReInit, setAllowLeadingWildcard, setDateResolution, setDateResolution, setDefaultOperator, setEnablePositionIncrements, setFuzzyMinSim, setFuzzyPrefixLength, setLocale, setLowercaseExpandedTerms, setPhraseSlop, setUseOldRangeQuery, Term, TopLevelQuery

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiFieldQueryParser

public MultiFieldQueryParser(java.lang.String[] fields,
                             Analyzer analyzer,
                             java.util.Map boosts)

Creates a MultiFieldQueryParser. Allows passing of a map with term to Boost, and the boost to apply to each term.

It will, when parse(String query) is called, construct a query like this (assuming the query consists of two terms and you specify the two fields title and body):

(title:term1 body:term1) (title:term2 body:term2)

When setDefaultOperator(AND_OPERATOR) is set, the result will be:

+(title:term1 body:term1) +(title:term2 body:term2)

When you pass a boost (title=>5 body=>10) you can get

+(title:term1^5.0 body:term1^10.0) +(title:term2^5.0 body:term2^10.0)

In other words, all the query's terms must appear, but it doesn't matter in what fields they appear.

MultiFieldQueryParser

public MultiFieldQueryParser(java.lang.String[] fields,
                             Analyzer analyzer)

Creates a MultiFieldQueryParser.

It will, when parse(String query) is called, construct a query like this (assuming the query consists of two terms and you specify the two fields title and body):

(title:term1 body:term1) (title:term2 body:term2)

When setDefaultOperator(AND_OPERATOR) is set, the result will be:

+(title:term1 body:term1) +(title:term2 body:term2)

In other words, all the query's terms must appear, but it doesn't matter in what fields they appear.

Method Detail

parse

public static Query parse(java.lang.String[] queries,
                          java.lang.String[] fields,
                          Analyzer analyzer)
                   throws ParseException

Parses a query which searches on the fields specified.

If x fields are specified, this effectively constructs:

 
 (field1:query1) (field2:query2) (field3:query3)...(fieldx:queryx)
 
 

Parameters:

queries - Queries strings to parse

fields - Fields to search on

analyzer - Analyzer to use

Throws:

ParseException - if query parsing fails

java.lang.IllegalArgumentException - if the length of the queries array differs from the length of the fields array

parse

public static Query parse(java.lang.String query,
                          java.lang.String[] fields,
                          BooleanClause.Occur[] flags,
                          Analyzer analyzer)
                   throws ParseException

Parses a query, searching on the fields specified. Use this if you need to specify certain fields as required, and others as prohibited.

 Usage:
 
 String[] fields = {"filename", "contents", "description"};
 BooleanClause.Occur[] flags = {BooleanClause.Occur.SHOULD,
                BooleanClause.Occur.MUST,
                BooleanClause.Occur.MUST_NOT};
 MultiFieldQueryParser.parse("query", fields, flags, analyzer);
 
 

The code above would construct a query:

 
 (filename:query) +(contents:query) -(description:query)
 
 

Parameters:

query - Query string to parse

fields - Fields to search on

flags - Flags describing the fields

analyzer - Analyzer to use

Throws:

ParseException - if query parsing fails

java.lang.IllegalArgumentException - if the length of the fields array differs from the length of the flags array

parse

public static Query parse(java.lang.String[] queries,
                          java.lang.String[] fields,
                          BooleanClause.Occur[] flags,
                          Analyzer analyzer)
                   throws ParseException

Parses a query, searching on the fields specified. Use this if you need to specify certain fields as required, and others as prohibited.

 Usage:
 
 String[] query = {"query1", "query2", "query3"};
 String[] fields = {"filename", "contents", "description"};
 BooleanClause.Occur[] flags = {BooleanClause.Occur.SHOULD,
                BooleanClause.Occur.MUST,
                BooleanClause.Occur.MUST_NOT};
 MultiFieldQueryParser.parse(query, fields, flags, analyzer);
 
 

The code above would construct a query:

 
 (filename:query1) +(contents:query2) -(description:query3)
 
 

Parameters:

queries - Queries string to parse

fields - Fields to search on

flags - Flags describing the fields

analyzer - Analyzer to use

Throws:

ParseException - if query parsing fails

java.lang.IllegalArgumentException - if the length of the queries, fields, and flags array differ