Class Query

    • Constructor Detail

      • Query

        public Query()
    • Method Detail

      • setBoost

        public void setBoost​(float b)
        Sets the boost for this query clause to b. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b.
      • getBoost

        public float getBoost()
        Gets the boost for this clause. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b. The boost is 1.0 by default.
      • toString

        public abstract String toString​(String field)
        Prints a query to a string, with field assumed to be the default field and omitted.

        The representation used is one that is supposed to be readable by QueryParser. However, there are the following limitations:

        • If the query was created by the parser, the printed representation may not be exactly what was parsed. For example, characters that need to be escaped will be represented without the required backslash.
        • Some of the more complicated queries (e.g. span queries) don't have a representation that can be parsed by QueryParser.
      • toString

        public String toString()
        Prints a query to a string.
        Overrides:
        toString in class Object
      • createWeight

        public Weight createWeight​(Searcher searcher)
                            throws IOException
        Expert: Constructs an appropriate Weight implementation for this query.

        Only implemented by primitive queries, which re-write to themselves.

        Throws:
        IOException
      • rewrite

        public Query rewrite​(IndexReader reader)
                      throws IOException
        Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.
        Throws:
        IOException
      • combine

        public Query combine​(Query[] queries)
        Expert: called when re-writing queries under MultiSearcher. Create a single query suitable for use by all subsearchers (in 1-1 correspondence with queries). This is an optimization of the OR of all queries. We handle the common optimization cases of equal queries and overlapping clauses of boolean OR queries (as generated by MultiTermQuery.rewrite()). Be careful overriding this method as queries[0] determines which method will be called and is not necessarily of the same type as the other queries.
      • extractTerms

        public void extractTerms​(Set<Term> terms)
        Expert: adds all terms occurring in this query to the terms set. Only works if this query is in its rewritten form.
        Throws:
        UnsupportedOperationException - if this query is not yet rewritten
      • mergeBooleanQueries

        public static Query mergeBooleanQueries​(BooleanQuery... queries)
        Expert: merges the clauses of a set of BooleanQuery's into a single BooleanQuery.

        A utility for use by combine(Query[]) implementations.

      • getSimilarity

        @Deprecated
        public Similarity getSimilarity​(Searcher searcher)
        Deprecated.
        Instead of using "runtime" subclassing/delegation, subclass the Weight instead.
        Expert: Returns the Similarity implementation to be used for this query. Subclasses may override this method to specify their own Similarity implementation, perhaps one that delegates through that of the Searcher. By default the Searcher's Similarity implementation is returned.
      • clone

        public Object clone()
        Returns a clone of this query.
        Overrides:
        clone in class Object
      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object