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 Details

    • FunctionScoreQuery

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

    • getWrappedQuery

      public Query getWrappedQuery()
      the wrapped Query
    • getSource

      public DoubleValuesSource getSource()
      the underlying value source
    • 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.

      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.

      in - the query to boost
      boostMatch - the boosting query
      boostValue - the amount to boost documents which match the boosting query
    • createWeight

      public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException
      createWeight in class Query
    • rewrite

      public Query rewrite(IndexReader reader) throws IOException
      rewrite in class Query
    • visit

      public void visit(QueryVisitor visitor)
      Specified by:
      visit in class Query
    • toString

      public String toString(String field)
      Specified by:
      toString in class Query
    • equals

      public boolean equals(Object o)
      Specified by:
      equals in class Query
    • hashCode

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