Package org.apache.lucene.search

Class ConstantScoreQuery

  • All Implemented Interfaces:
    Cloneable
    public class ConstantScoreQuery
extends Query
    A query that wraps another query or a filter and simply returns a constant score equal to the query boost for every document that matches the filter or query. For queries it therefore simply strips of all scores and returns a constant one.

    • Constructor Detail

      • ConstantScoreQuery

        public ConstantScoreQuery​(Query query)
        Strips off scores from the passed in Query. The hits will get a constant score dependent on the boost factor of this query.

      • ConstantScoreQuery

        public ConstantScoreQuery​(Filter filter)
        Wraps a Filter as a Query. The hits will get a constant score dependent on the boost factor of this query. If you simply want to strip off scores from a Query, no longer use new ConstantScoreQuery(new QueryWrapperFilter(query)), instead use ConstantScoreQuery(Query)!

    • Method Detail

      • getFilter

        public Filter getFilter()
        Returns the encapsulated filter, returns null if a query is wrapped.

      • getQuery

        public Query getQuery()
        Returns the encapsulated query, returns null if a filter is wrapped.

      • 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

      • extractTerms

        public void extractTerms​(Set<Term> terms)
        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

      • 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

      • toString

        public String toString​(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

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Query