Package org.apache.lucene.search.spans

Class SpanMultiTermQueryWrapper<Q extends MultiTermQuery>

  • All Implemented Interfaces:
    Serializable, Cloneable
    public class SpanMultiTermQueryWrapper<Q extends MultiTermQuery>
extends SpanQuery
    Wraps any MultiTermQuery as a SpanQuery, so it can be nested within other SpanQuery classes.

    The query is rewritten by default to a SpanOrQuery containing the expanded terms, but this can be customized.

    Example: 

     
 WildcardQuery wildcard = new WildcardQuery(new Term("field", "bro?n"));
 SpanQuery spanWildcard = new SpanMultiTermQueryWrapper<WildcardQuery>(wildcard);
 // do something with spanWildcard, such as use it in a SpanFirstQuery
    See Also:
    Serialized Form

    • Constructor Detail

      • SpanMultiTermQueryWrapper

        public SpanMultiTermQueryWrapper​(Q query)
        Create a new SpanMultiTermQueryWrapper.
        Parameters:
        query - Query to wrap.

        NOTE: This will call MultiTermQuery.setRewriteMethod(MultiTermQuery.RewriteMethod) on the wrapped query, changing its rewrite method to a suitable one for spans. Be sure to not change the rewrite method on the wrapped query afterwards! Doing so will throw UnsupportedOperationException on rewriting this query! In Lucene 3.x, MultiTermQuery allows queries to rewrite to different field names, but SpanQuery needs a fixed field. The wrapped query must therefore support getField() or getTerm().

        Throws:
        IllegalArgumentException - if the wrapped query does not provide getField() or getTerm().

    • Method Detail

      • getField

        public String getField()
        Description copied from class: SpanQuery
        Returns the name of the field matched by this query.
        Specified by:
        getField in class SpanQuery

      • 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

      • 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

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Query