Package org.apache.lucene.search
Class PhraseQuery
java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.search.PhraseQuery
- All Implemented Interfaces:
Cloneable
- Direct Known Subclasses:
NGramPhraseQuery
A Query that matches documents containing a particular sequence of terms.
A PhraseQuery is built by QueryParser for input like
"new york"
.
This query may be combined with other terms or queries with a BooleanQuery
.
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
Adds a term to the end of the query phrase.void
Adds a term to the end of the query phrase.createWeight
(IndexSearcher searcher) Expert: Constructs an appropriate Weight implementation for this query.boolean
Returns true iffo
is equal to this.void
extractTerms
(Set<Term> queryTerms) Expert: adds all terms occurring in this query to the terms set.int[]
Returns the relative positions of terms in this phrase.int
getSlop()
Returns the slop.Term[]
getTerms()
Returns the set of terms in this phrase.int
hashCode()
Returns a hash code value for this object.rewrite
(IndexReader reader) Expert: called to re-write queries into primitive queries.void
setSlop
(int s) Sets the number of other words permitted between words in query phrase.Prints a user-readable version of this query.
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Constructor Details
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PhraseQuery
public PhraseQuery()Constructs an empty phrase query.
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Method Details
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setSlop
public void setSlop(int s) Sets the number of other words permitted between words in query phrase. If zero, then this is an exact phrase search. For larger values this works like aWITHIN
orNEAR
operator.The slop is in fact an edit-distance, where the units correspond to moves of terms in the query phrase out of position. For example, to switch the order of two words requires two moves (the first move places the words atop one another), so to permit re-orderings of phrases, the slop must be at least two.
More exact matches are scored higher than sloppier matches, thus search results are sorted by exactness.
The slop is zero by default, requiring exact matches.
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getSlop
public int getSlop()Returns the slop. See setSlop(). -
add
Adds a term to the end of the query phrase. The relative position of the term is the one immediately after the last term added. -
add
Adds a term to the end of the query phrase. The relative position of the term within the phrase is specified explicitly. This allows e.g. phrases with more than one term at the same position or phrases with gaps (e.g. in connection with stopwords). -
getTerms
Returns the set of terms in this phrase. -
getPositions
public int[] getPositions()Returns the relative positions of terms in this phrase. -
rewrite
Description copied from class:Query
Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.- Overrides:
rewrite
in classQuery
- Throws:
IOException
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createWeight
Description copied from class:Query
Expert: Constructs an appropriate Weight implementation for this query.Only implemented by primitive queries, which re-write to themselves.
- Overrides:
createWeight
in classQuery
- Throws:
IOException
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extractTerms
Description copied from class:Query
Expert: adds all terms occurring in this query to the terms set. Only works if this query is in itsrewritten
form.- Overrides:
extractTerms
in classQuery
- See Also:
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toString
Prints a user-readable version of this query. -
equals
Returns true iffo
is equal to this. -
hashCode
public int hashCode()Returns a hash code value for this object.
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