Package org.apache.lucene.search

Class ConstantScoreQuery

  • All Implemented Interfaces:
    java.lang.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.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Weight createWeight​(IndexSearcher searcher)
      Expert: Constructs an appropriate Weight implementation for this query.
      boolean equals​(java.lang.Object o)  
      void extractTerms​(java.util.Set<Term> terms)
      Expert: adds all terms occurring in this query to the terms set.
      Filter getFilter()
      Returns the encapsulated filter, returns null if a query is wrapped.
      Query getQuery()
      Returns the encapsulated query, returns null if a filter is wrapped.
      int hashCode()  
      Query rewrite​(IndexReader reader)
      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.

      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait

    • 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 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.
        Overrides:
        rewrite in class Query
        Throws:
        java.io.IOException

      • extractTerms

        public void extractTerms​(java.util.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 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
        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 o)
        Overrides:
        equals in class Query

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Query