# Uses of Class
org.apache.lucene.index.IndexReader

Packages that use IndexReader
Package
Description
org.apache.lucene.index
Code to maintain and access indices.
org.apache.lucene.search
Code to search indices.
org.apache.lucene.util.hnsw
Navigable Small-World graph, nominally Hierarchical but currently only has a single layer.

## Uses of IndexReader in org.apache.lucene.index

Classes in org.apache.lucene.index with type parameters of type IndexReader
Modifier and Type
Class
Description
`class`
`BaseCompositeReader<R extends IndexReader>`
Base class for implementing `CompositeReader`s based on an array of sub-readers.
Subclasses of IndexReader in org.apache.lucene.index
Modifier and Type
Class
Description
`class`
`BaseCompositeReader<R extends IndexReader>`
Base class for implementing `CompositeReader`s based on an array of sub-readers.
`class`
`CodecReader`
LeafReader implemented by codec APIs.
`class`
`CompositeReader`
Instances of this reader type can only be used to get stored fields from the underlying LeafReaders, but it is not possible to directly retrieve postings.
`class`
`DirectoryReader`
DirectoryReader is an implementation of `CompositeReader` that can read indexes in a `Directory`.
`class`
`ExitableDirectoryReader`
The `ExitableDirectoryReader` wraps a real index `DirectoryReader` and allows for a `QueryTimeout` implementation object to be checked periodically to see if the thread should exit or not.
`static class`
`ExitableDirectoryReader.ExitableFilterAtomicReader`
Wrapper class for another FilterAtomicReader.
`class`
`FilterCodecReader`
A `FilterCodecReader` contains another CodecReader, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality.
`class`
`FilterDirectoryReader`
A FilterDirectoryReader wraps another DirectoryReader, allowing implementations to transform or extend it.
`class`
`FilterLeafReader`
A `FilterLeafReader` contains another LeafReader, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality.
`class`
`LeafReader`
`LeafReader` is an abstract class, providing an interface for accessing an index.
`class`
`MultiReader`
A `CompositeReader` which reads multiple indexes, appending their content.
`class`
`ParallelCompositeReader`
An `CompositeReader` which reads multiple, parallel indexes.
`class`
`ParallelLeafReader`
An `LeafReader` which reads multiple, parallel indexes.
`final class`
`SegmentReader`
IndexReader implementation over a single segment.
`final class`
`SoftDeletesDirectoryReaderWrapper`
This reader filters out documents that have a doc values value in the given field and treat these documents as soft deleted.
`final class`
`SortingCodecReader`
An `CodecReader` which supports sorting documents by a given `Sort`.
`final class`
`StandardDirectoryReader`
Default implementation of `DirectoryReader`.
Methods in org.apache.lucene.index that return IndexReader
Modifier and Type
Method
Description
`abstract IndexReader`
IndexReaderContext.`reader()`
Returns the `IndexReader`, this context represents.
Methods in org.apache.lucene.index that return types with arguments of type IndexReader
Modifier and Type
Method
Description
`protected abstract List<? extends IndexReader>`
CompositeReader.`getSequentialSubReaders()`
Expert: returns the sequential sub readers that this reader is logically composed of.
Methods in org.apache.lucene.index with parameters of type IndexReader
Modifier and Type
Method
Description
`static BinaryDocValues`
MultiDocValues.`getBinaryValues(IndexReader r, String field)`
Returns a BinaryDocValues for a reader's docvalues (potentially merging on-the-fly)
`static int`
PointValues.`getDocCount(IndexReader reader, String field)`
Return the cumulated number of docs that have points across all leaves of the given `IndexReader`.
`static Collection<String>`
FieldInfos.`getIndexedFields(IndexReader reader)`
Returns a set of names of fields that have a terms index.
`static Bits`
MultiBits.`getLiveDocs(IndexReader reader)`
Returns a single `Bits` instance for this reader, merging live Documents on the fly.
`static byte[]`
PointValues.`getMaxPackedValue(IndexReader reader, String field)`
Return the maximum packed values across all leaves of the given `IndexReader`.
`static FieldInfos`
FieldInfos.`getMergedFieldInfos(IndexReader reader)`
Call this to get the (merged) FieldInfos for a composite reader.
`static byte[]`
PointValues.`getMinPackedValue(IndexReader reader, String field)`
Return the minimum packed values across all leaves of the given `IndexReader`.
`static NumericDocValues`
MultiDocValues.`getNormValues(IndexReader r, String field)`
Returns a NumericDocValues for a reader's norms (potentially merging on-the-fly).
`static NumericDocValues`
MultiDocValues.`getNumericValues(IndexReader r, String field)`
Returns a NumericDocValues for a reader's docvalues (potentially merging on-the-fly)
`static SortedNumericDocValues`
MultiDocValues.`getSortedNumericValues(IndexReader r, String field)`
Returns a SortedNumericDocValues for a reader's docvalues (potentially merging on-the-fly)
`static SortedSetDocValues`
MultiDocValues.`getSortedSetValues(IndexReader r, String field)`
Returns a SortedSetDocValues for a reader's docvalues (potentially doing extremely slow things).
`static SortedDocValues`
MultiDocValues.`getSortedValues(IndexReader r, String field)`
Returns a SortedDocValues for a reader's docvalues (potentially doing extremely slow things).
`static PostingsEnum`
MultiTerms.`getTermPostingsEnum(IndexReader r, String field, BytesRef term)`
Returns `PostingsEnum` for the specified field and term.
`static PostingsEnum`
MultiTerms.`getTermPostingsEnum(IndexReader r, String field, BytesRef term, int flags)`
Returns `PostingsEnum` for the specified field and term, with control over whether freqs, positions, offsets or payloads are required.
`static Terms`
MultiTerms.`getTerms(IndexReader r, String field)`
This method may return null if the field does not exist or if it has no terms.
`final void`
IndexReader.`registerParentReader(IndexReader reader)`
Expert: This method is called by `IndexReader`s which wrap other readers (e.g.
`static long`
PointValues.`size(IndexReader reader, String field)`
Return the cumulated number of points across all leaves of the given `IndexReader`.
`long`
IndexWriter.`tryDeleteDocument(IndexReader readerIn, int docID)`
Expert: attempts to delete by document ID, as long as the provided reader is a near-real-time reader (from `DirectoryReader.open(IndexWriter)`).
`long`
IndexWriter.`tryUpdateDocValue(IndexReader readerIn, int docID, Field... fields)`
Expert: attempts to update doc values by document ID, as long as the provided reader is a near-real-time reader (from `DirectoryReader.open(IndexWriter)`).
Constructors in org.apache.lucene.index with parameters of type IndexReader
Modifier
Constructor
Description
`protected`
`BaseCompositeReader(R[] subReaders, Comparator<R> subReadersSorter)`
Constructs a `BaseCompositeReader` on the given subReaders.
``
`MultiReader(IndexReader... subReaders)`
Construct a MultiReader aggregating the named set of (sub)readers.
``
`MultiReader(IndexReader[] subReaders, boolean closeSubReaders)`
Construct a MultiReader aggregating the named set of (sub)readers.
``
`MultiReader(IndexReader[] subReaders, Comparator<IndexReader> subReadersSorter, boolean closeSubReaders)`
Construct a MultiReader aggregating the named set of (sub)readers.
Constructor parameters in org.apache.lucene.index with type arguments of type IndexReader
Modifier
Constructor
Description
``
`MultiReader(IndexReader[] subReaders, Comparator<IndexReader> subReadersSorter, boolean closeSubReaders)`
Construct a MultiReader aggregating the named set of (sub)readers.

## Uses of IndexReader in org.apache.lucene.search

Methods in org.apache.lucene.search that return IndexReader
Modifier and Type
Method
Description
`IndexReader`
IndexSearcher.`getIndexReader()`
Return the `IndexReader` this searches.
Methods in org.apache.lucene.search with parameters of type IndexReader
Modifier and Type
Method
Description
`static IndexSearcher`
SearcherManager.`getSearcher(SearcherFactory searcherFactory, IndexReader reader, IndexReader previousReader)`
Expert: creates a searcher from the provided `IndexReader` using the provided `SearcherFactory`.
`IndexSearcher`
SearcherFactory.`newSearcher(IndexReader reader, IndexReader previousReader)`
Returns a new IndexSearcher over the given reader.
Constructors in org.apache.lucene.search with parameters of type IndexReader
Modifier
Constructor
Description
``
`IndexSearcher(IndexReader r)`
Creates a searcher searching the provided index.
``
`IndexSearcher(IndexReader r, Executor executor)`
Runs searches for each segment separately, using the provided Executor.

## Uses of IndexReader in org.apache.lucene.util.hnsw

Methods in org.apache.lucene.util.hnsw with parameters of type IndexReader
Modifier and Type
Method
Description
`static boolean`
HnswUtil.`graphIsRooted(IndexReader reader, String vectorField)`
In graph theory, "connected components" are really defined only for undirected (ie bidirectional) graphs.