Package org.apache.lucene.search

Class ConstantScoreQuery

java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.search.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.

  • Field Details

    • filter

      protected final Filter filter

    • query

      protected final Query query

  • Constructor Details

    • 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 Details

    • 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

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Query

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Query