# Uses of Package
org.apache.lucene.index

Packages that use org.apache.lucene.index
Package | Description
--- | ---
org.apache.lucene.codecs | Codecs API: API for customization of the encoding and structure of the index.
org.apache.lucene.codecs.compressing | StoredFieldsFormat that allows cross-document and cross-field compression of stored fields.
org.apache.lucene.codecs.lucene3x | Codec to support Lucene 3.x indexes (readonly)
org.apache.lucene.codecs.lucene40 | Lucene 4.0 file format.
org.apache.lucene.codecs.lucene41 | Lucene 4.1 file format.
org.apache.lucene.codecs.lucene42 | Lucene 4.2 file format.
org.apache.lucene.codecs.perfield | Postings format that can delegate to different formats per-field.
org.apache.lucene.document | The logical representation of a `Document` for indexing and searching.
org.apache.lucene.index | Code to maintain and access indices.
org.apache.lucene.search | Code to search indices.
org.apache.lucene.search.payloads | The payloads package provides Query mechanisms for finding and using payloads.
org.apache.lucene.search.similarities | This package contains the various ranking models that can be used in Lucene.
org.apache.lucene.search.spans | The calculus of spans.
org.apache.lucene.util | Some utility classes.
org.apache.lucene.util.automaton | Finite-state automaton for regular expressions.

Classes in org.apache.lucene.index used by org.apache.lucene.codecs
Class and Description
BinaryDocValues A per-document byte[]
DocsAndPositionsEnum Also iterates through positions.
DocsEnum Iterates through the documents and term freqs.
FieldInfo Access to the Field Info file that describes document fields and whether or not they are indexed.
FieldInfo.IndexOptions Controls how much information is stored in the postings lists.
FieldInfos Collection of `FieldInfo`s (accessible by number or by name).
Fields Flex API for access to fields and terms
IndexableField Represents a single field for indexing.
MergeState Holds common state used during segment merging.
MultiDocsAndPositionsEnum.EnumWithSlice Holds a `DocsAndPositionsEnum` along with the corresponding `ReaderSlice`.
MultiDocsEnum.EnumWithSlice Holds a `DocsEnum` along with the corresponding `ReaderSlice`.
NumericDocValues A per-document numeric value.
OrdTermState An ordinal based `TermState`
SegmentInfo Information about a segment such as it's name, directory, and files related to the segment.
SegmentInfoPerCommit Embeds a [read-only] SegmentInfo and adds per-commit fields.
SegmentReadState Holder class for common parameters used during read.
SegmentWriteState Holder class for common parameters used during write.
SortedDocValues A per-document byte[] with presorted values.
SortedSetDocValues A per-document set of presorted byte[] values.
StoredFieldVisitor Expert: provides a low-level means of accessing the stored field values in an index.
Terms Access to the terms in a specific field.
TermsEnum Iterator to seek (`TermsEnum.seekCeil(BytesRef)`, `TermsEnum.seekExact(BytesRef,boolean)`) or step through (`BytesRefIterator.next()` terms to obtain frequency information (`TermsEnum.docFreq()`), `DocsEnum` or `DocsAndPositionsEnum` for the current term (`TermsEnum.docs(org.apache.lucene.util.Bits, org.apache.lucene.index.DocsEnum)`.
TermState Encapsulates all required internal state to position the associated `TermsEnum` without re-seeking.

Classes in org.apache.lucene.index used by org.apache.lucene.codecs.compressing
Class and Description
FieldInfo Access to the Field Info file that describes document fields and whether or not they are indexed.
FieldInfos Collection of `FieldInfo`s (accessible by number or by name).
Fields Flex API for access to fields and terms
IndexableField Represents a single field for indexing.
MergeState Holds common state used during segment merging.
SegmentInfo Information about a segment such as it's name, directory, and files related to the segment.
StoredFieldVisitor Expert: provides a low-level means of accessing the stored field values in an index.

Classes in org.apache.lucene.index used by org.apache.lucene.codecs.lucene3x
Class and Description
SegmentInfo Information about a segment such as it's name, directory, and files related to the segment.
SegmentInfos A collection of segmentInfo objects with methods for operating on those segments in relation to the file system.

Classes in org.apache.lucene.index used by org.apache.lucene.codecs.lucene40
Class and Description
DocsAndPositionsEnum Also iterates through positions.
DocsEnum Iterates through the documents and term freqs.
FieldInfo Access to the Field Info file that describes document fields and whether or not they are indexed.
FieldInfos Collection of `FieldInfo`s (accessible by number or by name).
Fields Flex API for access to fields and terms
IndexableField Represents a single field for indexing.
MergeState Holds common state used during segment merging.
SegmentInfo Information about a segment such as it's name, directory, and files related to the segment.
SegmentInfoPerCommit Embeds a [read-only] SegmentInfo and adds per-commit fields.
SegmentReadState Holder class for common parameters used during read.
SegmentWriteState Holder class for common parameters used during write.
StoredFieldVisitor Expert: provides a low-level means of accessing the stored field values in an index.

Classes in org.apache.lucene.index used by org.apache.lucene.codecs.lucene41
Class and Description
DocsAndPositionsEnum Also iterates through positions.
DocsEnum Iterates through the documents and term freqs.
FieldInfo Access to the Field Info file that describes document fields and whether or not they are indexed.
FieldInfos Collection of `FieldInfo`s (accessible by number or by name).
SegmentInfo Information about a segment such as it's name, directory, and files related to the segment.
SegmentReadState Holder class for common parameters used during read.
SegmentWriteState Holder class for common parameters used during write.

Classes in org.apache.lucene.index used by org.apache.lucene.codecs.lucene42
Class and Description
SegmentReadState Holder class for common parameters used during read.
SegmentWriteState Holder class for common parameters used during write.

Classes in org.apache.lucene.index used by org.apache.lucene.codecs.perfield
Class and Description
SegmentReadState Holder class for common parameters used during read.
SegmentWriteState Holder class for common parameters used during write.

Classes in org.apache.lucene.index used by org.apache.lucene.document
Class and Description
FieldInfo Access to the Field Info file that describes document fields and whether or not they are indexed.
FieldInfo.DocValuesType DocValues types.
FieldInfo.IndexOptions Controls how much information is stored in the postings lists.
IndexableField Represents a single field for indexing.
IndexableFieldType Describes the properties of a field.
StoredFieldVisitor Expert: provides a low-level means of accessing the stored field values in an index.
StoredFieldVisitor.Status Enumeration of possible return values for `StoredFieldVisitor.needsField(org.apache.lucene.index.FieldInfo)`.

Classes in org.apache.lucene.index used by org.apache.lucene.index
Class and Description
AtomicReader `AtomicReader` is an abstract class, providing an interface for accessing an index.
AtomicReaderContext `IndexReaderContext` for `AtomicReader` instances.
BaseCompositeReader Base class for implementing `CompositeReader`s based on an array of sub-readers.
BinaryDocValues A per-document byte[]
CheckIndex.Status Returned from `CheckIndex.checkIndex()` detailing the health and status of the index.
CheckIndex.Status.DocValuesStatus Status from testing DocValues
CheckIndex.Status.FieldNormStatus Status from testing field norms.
CheckIndex.Status.SegmentInfoStatus Holds the status of each segment in the index.
CheckIndex.Status.StoredFieldStatus Status from testing stored fields.
CheckIndex.Status.TermIndexStatus Status from testing term index.
CheckIndex.Status.TermVectorStatus Status from testing stored fields.
CompositeReader Instances of this reader type can only be used to get stored fields from the underlying AtomicReaders, but it is not possible to directly retrieve postings.
CompositeReaderContext `IndexReaderContext` for `CompositeReader` instance.
ConcurrentMergeScheduler.MergeThread Runs a merge thread, which may run one or more merges in sequence.
CorruptIndexException This exception is thrown when Lucene detects an inconsistency in the index.
DirectoryReader DirectoryReader is an implementation of `CompositeReader` that can read indexes in a `Directory`.
DocsAndPositionsEnum Also iterates through positions.
DocsEnum Iterates through the documents and term freqs.
FieldInfo Access to the Field Info file that describes document fields and whether or not they are indexed.
FieldInfo.DocValuesType DocValues types.
FieldInfo.IndexOptions Controls how much information is stored in the postings lists.
FieldInfos Collection of `FieldInfo`s (accessible by number or by name).
Fields Flex API for access to fields and terms
FilteredTermsEnum Abstract class for enumerating a subset of all terms.
FilteredTermsEnum.AcceptStatus Return value, if term should be accepted or the iteration should `END`.
IndexableField Represents a single field for indexing.
IndexableFieldType Describes the properties of a field.
IndexCommit Expert: represents a single commit into an index as seen by the `IndexDeletionPolicy` or `IndexReader`.
IndexDeletionPolicy Expert: policy for deletion of stale `index commits`.
IndexReader IndexReader is an abstract class, providing an interface for accessing an index.
IndexReader.ReaderClosedListener A custom listener that's invoked when the IndexReader is closed.
IndexReaderContext A struct like class that represents a hierarchical relationship between `IndexReader` instances.
IndexWriter An `IndexWriter` creates and maintains an index.
IndexWriter.IndexReaderWarmer If `DirectoryReader.open(IndexWriter,boolean)` has been called (ie, this writer is in near real-time mode), then after a merge completes, this class can be invoked to warm the reader on the newly merged segment, before the merge commits.
IndexWriterConfig Holds all the configuration that is used to create an `IndexWriter`.
IndexWriterConfig.OpenMode Specifies the open mode for `IndexWriter`.
LiveIndexWriterConfig Holds all the configuration used by `IndexWriter` with few setters for settings that can be changed on an `IndexWriter` instance "live".
LogMergePolicy This class implements a `MergePolicy` that tries to merge segments into levels of exponentially increasing size, where each level has fewer segments than the value of the merge factor.
MergePolicy Expert: a MergePolicy determines the sequence of primitive merge operations.
MergePolicy.MergeAbortedException Thrown when a merge was explicity aborted because `IndexWriter.close(boolean)` was called with `false`.
MergePolicy.MergeSpecification A MergeSpecification instance provides the information necessary to perform multiple merges.
MergePolicy.MergeTrigger MergeTrigger is passed to `MergePolicy.findMerges(MergeTrigger, SegmentInfos)` to indicate the event that triggered the merge.
MergePolicy.OneMerge OneMerge provides the information necessary to perform an individual primitive merge operation, resulting in a single new segment.
MergeScheduler Expert: `IndexWriter` uses an instance implementing this interface to execute the merges selected by a `MergePolicy`.
MergeState.CheckAbort Class for recording units of work when merging segments.
MergeState.DocMap Remaps docids around deletes during merge
MultiDocsAndPositionsEnum Exposes flex API, merged from flex API of sub-segments.
MultiDocsAndPositionsEnum.EnumWithSlice Holds a `DocsAndPositionsEnum` along with the corresponding `ReaderSlice`.
MultiDocsEnum.EnumWithSlice Holds a `DocsEnum` along with the corresponding `ReaderSlice`.
MultiDocValues.OrdinalMap maps per-segment ordinals to/from global ordinal space
MultiTermsEnum Exposes `TermsEnum` API, merged from `TermsEnum` API of sub-segments.
NumericDocValues A per-document numeric value.
ReaderSlice Subreader slice from a parent composite reader.
SegmentInfo Information about a segment such as it's name, directory, and files related to the segment.
SegmentInfoPerCommit Embeds a [read-only] SegmentInfo and adds per-commit fields.
SegmentInfos A collection of segmentInfo objects with methods for operating on those segments in relation to the file system.
SegmentReader IndexReader implementation over a single segment.
SegmentReader.CoreClosedListener Called when the shared core for this SegmentReader is closed.
SegmentReadState Holder class for common parameters used during read.
SegmentWriteState Holder class for common parameters used during write.
SnapshotDeletionPolicy An `IndexDeletionPolicy` that wraps around any other `IndexDeletionPolicy` and adds the ability to hold and later release snapshots of an index.
SortedDocValues A per-document byte[] with presorted values.
SortedSetDocValues A per-document set of presorted byte[] values.
StoredFieldVisitor Expert: provides a low-level means of accessing the stored field values in an index.
StoredFieldVisitor.Status Enumeration of possible return values for `StoredFieldVisitor.needsField(org.apache.lucene.index.FieldInfo)`.
Term A Term represents a word from text.
TermContext Maintains a `IndexReader` `TermState` view over `IndexReader` instances containing a single term.
Terms Access to the terms in a specific field.
TermsEnum Iterator to seek (`TermsEnum.seekCeil(BytesRef)`, `TermsEnum.seekExact(BytesRef,boolean)`) or step through (`BytesRefIterator.next()` terms to obtain frequency information (`TermsEnum.docFreq()`), `DocsEnum` or `DocsAndPositionsEnum` for the current term (`TermsEnum.docs(org.apache.lucene.util.Bits, org.apache.lucene.index.DocsEnum)`.
TermsEnum.SeekStatus Represents returned result from `TermsEnum.seekCeil(org.apache.lucene.util.BytesRef, boolean)`.
TermState Encapsulates all required internal state to position the associated `TermsEnum` without re-seeking.
TieredMergePolicy Merges segments of approximately equal size, subject to an allowed number of segments per tier.
TieredMergePolicy.MergeScore Holds score and explanation for a single candidate merge.
TwoPhaseCommit An interface for implementations that support 2-phase commit.
TwoPhaseCommitTool.CommitFailException Thrown by `TwoPhaseCommitTool.execute(TwoPhaseCommit...)` when an object fails to commit().
TwoPhaseCommitTool.PrepareCommitFailException Thrown by `TwoPhaseCommitTool.execute(TwoPhaseCommit...)` when an object fails to prepareCommit().

Classes in org.apache.lucene.index used by org.apache.lucene.search
Class and Description
AtomicReader `AtomicReader` is an abstract class, providing an interface for accessing an index.
AtomicReaderContext `IndexReaderContext` for `AtomicReader` instances.
BinaryDocValues A per-document byte[]
DocsAndPositionsEnum Also iterates through positions.
DocsEnum Iterates through the documents and term freqs.
FilteredTermsEnum Abstract class for enumerating a subset of all terms.
FilteredTermsEnum.AcceptStatus Return value, if term should be accepted or the iteration should `END`.
IndexableField Represents a single field for indexing.
IndexReader IndexReader is an abstract class, providing an interface for accessing an index.
IndexReaderContext A struct like class that represents a hierarchical relationship between `IndexReader` instances.
IndexWriter An `IndexWriter` creates and maintains an index.
SortedDocValues A per-document byte[] with presorted values.
SortedSetDocValues A per-document set of presorted byte[] values.
StoredFieldVisitor Expert: provides a low-level means of accessing the stored field values in an index.
Term A Term represents a word from text.
TermContext Maintains a `IndexReader` `TermState` view over `IndexReader` instances containing a single term.
Terms Access to the terms in a specific field.
TermsEnum Iterator to seek (`TermsEnum.seekCeil(BytesRef)`, `TermsEnum.seekExact(BytesRef,boolean)`) or step through (`BytesRefIterator.next()` terms to obtain frequency information (`TermsEnum.docFreq()`), `DocsEnum` or `DocsAndPositionsEnum` for the current term (`TermsEnum.docs(org.apache.lucene.util.Bits, org.apache.lucene.index.DocsEnum)`.
TermsEnum.SeekStatus Represents returned result from `TermsEnum.seekCeil(org.apache.lucene.util.BytesRef, boolean)`.
TermState Encapsulates all required internal state to position the associated `TermsEnum` without re-seeking.

Classes in org.apache.lucene.index used by org.apache.lucene.search.payloads
Class and Description
AtomicReaderContext `IndexReaderContext` for `AtomicReader` instances.
DocsEnum Iterates through the documents and term freqs.
IndexReaderContext A struct like class that represents a hierarchical relationship between `IndexReader` instances.
Term A Term represents a word from text.

Classes in org.apache.lucene.index used by org.apache.lucene.search.similarities
Class and Description
AtomicReaderContext `IndexReaderContext` for `AtomicReader` instances.
FieldInvertState This class tracks the number and position / offset parameters of terms being added to the index.

Classes in org.apache.lucene.index used by org.apache.lucene.search.spans
Class and Description
AtomicReaderContext `IndexReaderContext` for `AtomicReader` instances.
DocsAndPositionsEnum Also iterates through positions.
DocsEnum Iterates through the documents and term freqs.
IndexReader IndexReader is an abstract class, providing an interface for accessing an index.
Term A Term represents a word from text.
TermContext Maintains a `IndexReader` `TermState` view over `IndexReader` instances containing a single term.

Classes in org.apache.lucene.index used by org.apache.lucene.util
Class and Description
TermsEnum Iterator to seek (`TermsEnum.seekCeil(BytesRef)`, `TermsEnum.seekExact(BytesRef,boolean)`) or step through (`BytesRefIterator.next()` terms to obtain frequency information (`TermsEnum.docFreq()`), `DocsEnum` or `DocsAndPositionsEnum` for the current term (`TermsEnum.docs(org.apache.lucene.util.Bits, org.apache.lucene.index.DocsEnum)`.

Classes in org.apache.lucene.index used by org.apache.lucene.util.automaton
Class and Description
Terms Access to the terms in a specific field.
TermsEnum Iterator to seek (`TermsEnum.seekCeil(BytesRef)`, `TermsEnum.seekExact(BytesRef,boolean)`) or step through (`BytesRefIterator.next()` terms to obtain frequency information (`TermsEnum.docFreq()`), `DocsEnum` or `DocsAndPositionsEnum` for the current term (`TermsEnum.docs(org.apache.lucene.util.Bits, org.apache.lucene.index.DocsEnum)`.