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
public class PhraseQuery extends Query
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.

  • Constructor Summary

    Constructors
    Constructor
    Description
    PhraseQuery()
    Constructs an empty phrase query.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(Term term)
    Adds a term to the end of the query phrase.
    void
    add(Term term, int position)
    Adds a term to the end of the query phrase.
    Weight
    createWeight(IndexSearcher searcher)
    Expert: Constructs an appropriate Weight implementation for this query.
    boolean
    equals(Object o)
    Returns true iff o is equal to this.
    void
    extractTerms(Set<Term> queryTerms)
    Expert: adds all terms occurring in this query to the terms set.
    int[]
    getPositions()
    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.
    Query
    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.
    String
    toString(String f)
    Prints a user-readable version of this query.

    Methods inherited from class org.apache.lucene.search.Query

    clone, getBoost, setBoost, toString

    Methods inherited from class java.lang.Object

    finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • PhraseQuery

      public PhraseQuery()
      Constructs an empty phrase query.

  • Method Details

    • 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 a WITHIN or NEAR 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.

    • getSlop

      public int getSlop()
      Returns the slop. See setSlop().

    • add

      public void add(Term term)
      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

      public void add(Term term, int position)
      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

      public Term[] getTerms()
      Returns the set of terms in this phrase.

    • getPositions

      public int[] getPositions()
      Returns the relative positions of terms in this phrase.

    • rewrite

      public Query rewrite(IndexReader reader) throws IOException
      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 class Query
      Throws:
      IOException

    • createWeight

      public Weight createWeight(IndexSearcher searcher) throws IOException
      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 class Query
      Throws:
      IOException

    • extractTerms

      public void extractTerms(Set<Term> queryTerms)
      Description copied from class: Query
      Expert: adds all terms occurring in this query to the terms set. Only works if this query is in its rewritten form.
      Overrides:
      extractTerms in class Query
      See Also:

    • toString

      public String toString(String f)
      Prints a user-readable version of this query.
      Specified by:
      toString in class Query

    • equals

      public boolean equals(Object o)
      Returns true iff o is equal to this.
      Overrides:
      equals in class Query

    • hashCode

      public int hashCode()
      Returns a hash code value for this object.
      Overrides:
      hashCode in class Query