Class MatchScorer

  • Direct Known Subclasses:
    RescoringMatchScorer

    public class MatchScorer
    extends Object
    Assigns a document score based on frequency of terms in TextFields and HTMLFields.

    If you add a MatchScorer to a SortOptions as in the following code:

    
      SortOptions sortOptions = SortOptions.newBuilder()
          .setMatchScorer(MatchScorer.newBuilder())
          .build();
     
    then this will sort the documents in descending score order. The scores will be positive. If you want to sort in ascending order, then use the following code:
    
       SortOptions sortOptions = SortOptions.newBuilder()
           .setMatchScorer(MatchScorer.newBuilder())
           .addSortExpression(
               SortExpression.newBuilder()
                   .setExpression(SortExpression.SCORE_FIELD_NAME)
                   .setDirection(SortExpression.SortDirection.ASCENDING)
                   .setDefaultValueNumeric(0.0))
           .build();
     
    In this example, the score will be negative.