Class ToChildBlockJoinQuery

  • All Implemented Interfaces:
    Serializable, Cloneable

    public class ToChildBlockJoinQuery
    extends Query
    Just like ToParentBlockJoinQuery, except this query joins in reverse: you provide a Query matching parent documents and it joins down to child documents.

    WARNING: to create the parents filter, always use RawTermFilter (so that the filter includes deleted docs), wrapped with CachingWrapperFilter (so that the returned bit set per reader is a FixedBitSet), specifying DeletesMode.IGNORE (so that on reopen, the filter still includes deleted docs). Failure to do this can result in completely wrong documents being returned! For example:

       Filter parents = new CachingWrapperFilter(
                              new RawTermFilter(new Term("parent", "yes")),
                              CachingWrapperFilter.DeletesMode.IGNORE);
     
    See Also:
    Serialized Form
    WARNING: This API is experimental and might change in incompatible ways in the next release.
    • Constructor Detail

      • ToChildBlockJoinQuery

        public ToChildBlockJoinQuery​(Query parentQuery,
                                     Filter parentsFilter,
                                     boolean doScores)
    • Method Detail

      • createWeight

        public Weight createWeight​(Searcher 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
      • 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
      • 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
      • toString

        public String toString​(String field)
        Description copied from class: Query
        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.
        Specified by:
        toString in class Query
      • equals

        public boolean equals​(Object _other)
        Overrides:
        equals in class Query
      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Query
      • clone

        public Object clone()
        Description copied from class: Query
        Returns a clone of this query.
        Overrides:
        clone in class Query