Class FunctionScoreQuery


  • public final class FunctionScoreQuery
    extends Query
    A query that wraps another query, and uses a DoubleValuesSource to replace or modify the wrapped query's score

    If the DoubleValuesSource doesn't return a value for a particular document, then that document will be given a score of 0.

    • Constructor Detail

      • FunctionScoreQuery

        public FunctionScoreQuery​(Query in,
                                  DoubleValuesSource source)
        Create a new FunctionScoreQuery
        Parameters:
        in - the query to wrap
        source - a source of scores
    • Method Detail

      • getWrappedQuery

        public Query getWrappedQuery()
        Returns:
        the wrapped Query
      • boostByValue

        public static FunctionScoreQuery boostByValue​(Query in,
                                                      DoubleValuesSource boost)
        Returns a FunctionScoreQuery where the scores of a wrapped query are multiplied by the value of a DoubleValuesSource.

        If the source has no value for a particular document, the score for that document is preserved as-is.

        Parameters:
        in - the query to boost
        boost - a DoubleValuesSource containing the boost values
      • boostByQuery

        public static FunctionScoreQuery boostByQuery​(Query in,
                                                      Query boostMatch,
                                                      float boostValue)
        Returns a FunctionScoreQuery where the scores of a wrapped query are multiplied by a boost factor if the document being scored also matches a separate boosting query.

        Documents that do not match the boosting query have their scores preserved.

        This may be used to 'demote' documents that match the boosting query, by passing in a boostValue between 0 and 1.

        Parameters:
        in - the query to boost
        boostMatch - the boosting query
        boostValue - the amount to boost documents which match the boosting query
      • hashCode

        public int hashCode()
        Specified by:
        hashCode in class Query