Class ConstantScoreQuery


  • public final class ConstantScoreQuery
    extends Query
    A query that wraps another query and simply returns a constant score equal to 1 for every document that matches the query. It therefore simply strips of all scores and always returns 1.
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      protected static class  ConstantScoreQuery.ConstantBulkScorer
      We return this as our BulkScorer so that if the CSQ wraps a query with its own optimized top-level scorer (e.g.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private Query query  
    • Constructor Summary

      Constructors 
      Constructor Description
      ConstantScoreQuery​(Query query)
      Strips off scores from the passed in Query.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Weight createWeight​(IndexSearcher searcher, ScoreMode scoreMode, float boost)
      Expert: Constructs an appropriate Weight implementation for this query.
      boolean equals​(java.lang.Object other)
      Override and implement query instance equivalence properly in a subclass.
      Query getQuery()
      Returns the encapsulated query.
      int hashCode()
      Override and implement query hash code properly in a subclass.
      Query rewrite​(IndexSearcher indexSearcher)
      Expert: called to re-write queries into primitive queries.
      java.lang.String toString​(java.lang.String field)
      Prints a query to a string, with field assumed to be the default field and omitted.
      void visit​(QueryVisitor visitor)
      Recurse through the query tree, visiting any child queries.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
    • Field Detail

      • query

        private final Query query
    • Constructor Detail

      • ConstantScoreQuery

        public ConstantScoreQuery​(Query query)
        Strips off scores from the passed in Query. The hits will get a constant score of 1.
    • Method Detail

      • getQuery

        public Query getQuery()
        Returns the encapsulated query.
      • rewrite

        public Query rewrite​(IndexSearcher indexSearcher)
                      throws java.io.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.

        Callers are expected to call rewrite multiple times if necessary, until the rewritten query is the same as the original query.

        The rewrite process may be able to make use of IndexSearcher's executor and be executed in parallel if the executor is provided.

        However, if any of the intermediary queries do not satisfy the new API, parallel rewrite is not possible for any subsequent sub-queries. To take advantage of this API, the entire query tree must override this method.

        Overrides:
        rewrite in class Query
        Throws:
        java.io.IOException
        See Also:
        IndexSearcher.rewrite(Query)
      • visit

        public void visit​(QueryVisitor visitor)
        Description copied from class: Query
        Recurse through the query tree, visiting any child queries.
        Specified by:
        visit in class Query
        Parameters:
        visitor - a QueryVisitor to be called by each query in the tree
      • createWeight

        public Weight createWeight​(IndexSearcher searcher,
                                   ScoreMode scoreMode,
                                   float boost)
                            throws java.io.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
        scoreMode - How the produced scorers will be consumed.
        boost - The boost that is propagated by the parent queries.
        Throws:
        java.io.IOException
      • toString

        public java.lang.String toString​(java.lang.String field)
        Description copied from class: Query
        Prints a query to a string, with field assumed to be the default field and omitted.
        Specified by:
        toString in class Query
      • equals

        public boolean equals​(java.lang.Object other)
        Description copied from class: Query
        Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly.

        Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical to those of the other instance. Utility methods are provided for certain repetitive code.

        Specified by:
        equals in class Query
        See Also:
        Query.sameClassAs(Object), Query.classHash()
      • hashCode

        public int hashCode()
        Description copied from class: Query
        Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.
        Specified by:
        hashCode in class Query
        See Also:
        Query.equals(Object)