## 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.

Version:
  $Revision: 965592 $

Nested Class Summary

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

Field Summary
`protected Map<String,Float>` `boosts`
`protected String[]` `fields`

Fields inherited from class org.apache.lucene.queryParser.QueryParser
`AND_OPERATOR, jj_nt, OR_OPERATOR, token, token_source`

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

`_ESCAPED_CHAR, _NUM_CHAR, _QUOTED_CHAR, _TERM_CHAR, _TERM_START_CHAR, _WHITESPACE, AND, BAREOPER, 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
`MultiFieldQueryParser(Version matchVersion, String[] fields, Analyzer analyzer)` Creates a MultiFieldQueryParser.
`MultiFieldQueryParser(Version matchVersion, String[] fields, Analyzer analyzer, Map<String,Float> boosts)` Creates a MultiFieldQueryParser.

Method Summary
`protected Query` `getFieldQuery(String field, String queryText, boolean quoted)`
`protected Query` `getFieldQuery(String field, String queryText, int slop)` Base implementation delegates to `QueryParser.getFieldQuery(String,String,boolean)`.
`protected Query` `getFuzzyQuery(String field, String termStr, float minSimilarity)` Factory method for generating a query (similar to `QueryParser.getWildcardQuery(java.lang.String, java.lang.String)`).
`protected Query` `getPrefixQuery(String field, String termStr)` Factory method for generating a query (similar to `QueryParser.getWildcardQuery(java.lang.String, java.lang.String)`).
`protected Query` `getRangeQuery(String field, String part1, String part2, boolean inclusive)`
`protected Query` `getWildcardQuery(String field, String termStr)` Factory method for generating a query.
`static Query` `parse(Version matchVersion, String[] queries, String[] fields, Analyzer analyzer)` Parses a query which searches on the fields specified.
`static Query` `parse(Version matchVersion, String[] queries, String[] fields, BooleanClause.Occur[] flags, Analyzer analyzer)` Parses a query, searching on the fields specified.
`static Query` `parse(Version matchVersion, String query, String[] fields, BooleanClause.Occur[] flags, Analyzer analyzer)` Parses a query, searching on the fields specified.

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

`addClause, Clause, Conjunction, disable_tracing, enable_tracing, escape, generateParseException, getAllowLeadingWildcard, getAnalyzer, getAutoGeneratePhraseQueries, getBooleanQuery, getBooleanQuery, getDateResolution, getDefaultOperator, getEnablePositionIncrements, getField, getFieldQuery, getFuzzyMinSim, getFuzzyPrefixLength, getLocale, getLowercaseExpandedTerms, getMultiTermRewriteMethod, getNextToken, getPhraseSlop, getRangeCollator, getToken, main, Modifiers, newBooleanClause, newBooleanQuery, newFuzzyQuery, newMatchAllDocsQuery, newMultiPhraseQuery, newPhraseQuery, newPrefixQuery, newRangeQuery, newTermQuery, newWildcardQuery, parse, Query, ReInit, ReInit, setAllowLeadingWildcard, setAutoGeneratePhraseQueries, setDateResolution, setDateResolution, setDefaultOperator, setEnablePositionIncrements, setFuzzyMinSim, setFuzzyPrefixLength, setLocale, setLowercaseExpandedTerms, setMultiTermRewriteMethod, setPhraseSlop, setRangeCollator, Term, TopLevelQuery`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### fields

    protected String[] fields

### boosts

    protected Map<String,Float> boosts

Constructor Detail

### MultiFieldQueryParser

    public MultiFieldQueryParser(Version matchVersion,
                                 String[] fields,
                                 Analyzer analyzer,
                                 Map<String,Float> 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(Version matchVersion,
                                 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

### getFieldQuery

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

  Description copied from class: `QueryParser`
  Base implementation delegates to `QueryParser.getFieldQuery(String,String,boolean)`. This method may be overridden, for example, to return a SpanNearQuery instead of a PhraseQuery.

  Overrides:
    `getFieldQuery` in class `QueryParser`
  Throws:
    `ParseException` - throw in overridden method to disallow

### getFieldQuery

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

  Overrides:
    `getFieldQuery` in class `QueryParser`
  Throws:
    `ParseException` - throw in overridden method to disallow

### getFuzzyQuery

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

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

  Overrides:
    `getFuzzyQuery` in class `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` - throw in overridden method to disallow

### getPrefixQuery

    protected Query getPrefixQuery(String field,
                                   String termStr)
                            throws ParseException

  Description copied from class: `QueryParser`
  Factory method for generating a query (similar to `QueryParser.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.

  Overrides:
    `getPrefixQuery` in class `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` - throw in overridden method to disallow

### getWildcardQuery

    protected Query getWildcardQuery(String field,
                                     String termStr)
                              throws ParseException

  Description copied from class: `QueryParser`
  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.

  Overrides:
    `getWildcardQuery` in class `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` - throw in overridden method to disallow

### getRangeQuery

    protected Query getRangeQuery(String field,
                                  String part1,
                                  String part2,
                                  boolean inclusive)
                           throws ParseException

  Overrides:
    `getRangeQuery` in class `QueryParser`
  Throws:
    `ParseException` - throw in overridden method to disallow

### parse

    public static Query parse(Version matchVersion,
                              String[] queries,
                              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:
    `matchVersion` - Lucene version to match; this is passed through to QueryParser.
    `queries` - Queries strings to parse
    `fields` - Fields to search on
    `analyzer` - Analyzer to use
  Throws:
    `ParseException` - if query parsing fails
    `IllegalArgumentException` - if the length of the queries array differs from the length of the fields array

### parse

    public static Query parse(Version matchVersion,
                              String query,
                              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:
    `matchVersion` - Lucene version to match; this is passed through to QueryParser.
    `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
    `IllegalArgumentException` - if the length of the fields array differs from the length of the flags array

### parse

    public static Query parse(Version matchVersion,
                              String[] queries,
                              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:
    `matchVersion` - Lucene version to match; this is passed through to QueryParser.
    `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
    `IllegalArgumentException` - if the length of the queries, fields, and flags array differ