Class SpanFilter

  • All Implemented Interfaces:
    Serializable
    Direct Known Subclasses:
    CachingSpanFilter, SpanQueryFilter

    public abstract class SpanFilter
    extends Filter
    Abstract base class providing a mechanism to restrict searches to a subset of an index and also maintains and returns position information. This is useful if you want to compare the positions from a SpanQuery with the positions of items in a filter. For instance, if you had a SpanFilter that marked all the occurrences of the word "foo" in documents, and then you entered a new SpanQuery containing bar, you could not only filter by the word foo, but you could then compare position information for post processing.
    See Also:
    Serialized Form
    • Constructor Detail

      • SpanFilter

        public SpanFilter()
    • Method Detail

      • bitSpans

        public abstract SpanFilterResult bitSpans​(IndexReader reader)
                                           throws IOException
        Returns a SpanFilterResult with true for documents which should be permitted in search results, and false for those that should not and Spans for where the true docs match.
        Parameters:
        reader - The IndexReader to load position and DocIdSet information from
        Returns:
        A SpanFilterResult
        Throws:
        IOException - if there was an issue accessing the necessary information