Package org.apache.lucene.queries.function

Class FunctionQuery

java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.queries.function.FunctionQuery
All Implemented Interfaces:
Cloneable
public class FunctionQuery extends Query
Returns a score for each document based on a ValueSource, often some function of the value of a field. Note: This API is experimental and may change in non backward-compatible ways in the future

  • Constructor Details

    • FunctionQuery

      public FunctionQuery(ValueSource func)
      Parameters:
      func - defines the function to be used for scoring

  • Method Details

    • getValueSource

      public ValueSource getValueSource()
      Returns:
      The associated ValueSource

    • 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)
      Prints a user-readable version of this query.
      Specified by:
      toString in class Query

    • equals

      public boolean equals(Object o)
      Returns true if o is equal to this.
      Overrides:
      equals in class Query

    • hashCode

      public int hashCode()
      Returns a hash code value for this object.
      Overrides:
      hashCode in class Query