org.apache.lucene.search
Class Filter
java.lang.Object
org.apache.lucene.search.Filter
- Direct Known Subclasses:
- CachingWrapperFilter, DocTermOrdsRangeFilter, FieldCacheRangeFilter, FieldCacheTermsFilter, FieldValueFilter, MultiTermQueryWrapperFilter, QueryWrapperFilter
public abstract class Filter
- extends Object
Abstract base class for restricting which documents may
be returned during searching.
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Filter
public Filter()
getDocIdSet
public abstract DocIdSet getDocIdSet(AtomicReaderContext context,
Bits acceptDocs)
throws IOException
- Creates a
DocIdSet
enumerating the documents that should be
permitted in search results. NOTE: null can be
returned if no documents are accepted by this Filter.
Note: This method will be called once per segment in
the index during searching. The returned DocIdSet
must refer to document IDs for that segment, not for
the top-level reader.
- Parameters:
context
- a AtomicReaderContext
instance opened on the index currently
searched on. Note, it is likely that the provided reader info does not
represent the whole underlying index i.e. if the index has more than
one segment the given reader only represents a single segment.
The provided context is always an atomic context, so you can call
AtomicReader.fields()
on the context's reader, for example.acceptDocs
- Bits that represent the allowable docs to match (typically deleted docs
but possibly filtering other documents)
- Returns:
- a DocIdSet that provides the documents which should be permitted or
prohibited in search results. NOTE:
null
should be returned if
the filter doesn't accept any documents otherwise internal optimization might not apply
in the case an empty DocIdSet
is returned.
- Throws:
IOException
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