Package org.apache.lucene.search

Class CoveringQuery

  • All Implemented Interfaces:
    Accountable
    public final class CoveringQuery
extends Query
implements Accountable
    A Query that allows to have a configurable number or required matches per document. This is typically useful in order to build queries whose query terms must all appear in documents.

    • Field Detail

      • BASE_RAM_BYTES

        private static final long BASE_RAM_BYTES

      • queries

        private final java.util.Collection<Query> queries

      • hashCode

        private final int hashCode

      • ramBytesUsed

        private final long ramBytesUsed

    • Constructor Detail

      • CoveringQuery

        public CoveringQuery​(java.util.Collection<Query> queries,
                     LongValuesSource minimumNumberMatch)
        Sole constructor.
        Parameters:
        queries - Sub queries to match.
        minimumNumberMatch - Per-document long value that records how many queries should match. Values that are less than 1 are treated like 1: only documents that have at least one matching clause will be considered matches. Documents that do not have a value for minimumNumberMatch do not match.

    • Method Detail

      • toString

        public java.lang.String toString​(java.lang.String field)
        Description copied from class: Query
        Prints a query to a string, with field assumed to be the default field and omitted.
        Specified by:
        toString in class Query

      • equals

        public boolean equals​(java.lang.Object obj)
        Description copied from class: Query
        Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly. Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical that other instance. Utility methods are provided for certain repetitive code.
        Specified by:
        equals in class Query
        See Also:
        Query.sameClassAs(Object), Query.classHash()

      • computeHashCode

        private int computeHashCode()

      • hashCode

        public int hashCode()
        Description copied from class: Query
        Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.
        Specified by:
        hashCode in class Query
        See Also:
        Query.equals(Object)

      • ramBytesUsed

        public long ramBytesUsed()
        Description copied from interface: Accountable
        Return the memory usage of this object in bytes. Negative values are illegal.
        Specified by:
        ramBytesUsed in interface Accountable

      • rewrite

        public Query rewrite​(IndexReader reader)
              throws java.io.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:
        java.io.IOException

      • visit

        public void visit​(QueryVisitor visitor)
        Description copied from class: Query
        Recurse through the query tree, visiting any child queries
        Overrides:
        visit in class Query
        Parameters:
        visitor - a QueryVisitor to be called by each query in the tree

      • createWeight

        public Weight createWeight​(IndexSearcher searcher,
                           ScoreMode scoreMode,
                           float boost)
                    throws java.io.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
        scoreMode - How the produced scorers will be consumed.
        boost - The boost that is propagated by the parent queries.
        Throws:
        java.io.IOException