org.apache.lucene.index

Class PostingsEnum

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.index.PostingsEnum

Direct Known Subclasses:

FilterLeafReader.FilterPostingsEnum, ImpactsEnum, MultiPostingsEnum

public abstract class PostingsEnum
extends DocIdSetIterator

Iterates through the postings. NOTE: you must first call DocIdSetIterator.nextDoc() before using any of the per-doc methods.

Field Summary

Fields

Modifier and Type	Field and Description
static short	ALL Flag to pass to TermsEnum.postings(PostingsEnum, int) to get positions, payloads and offsets in the returned enum
static short	FREQS Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require term frequencies in the returned enum.
static short	NONE Flag to pass to TermsEnum.postings(PostingsEnum, int) if you don't require per-document postings in the returned enum.
static short	OFFSETS Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require offsets in the returned enum.
static short	PAYLOADS Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require payloads in the returned enum.
static short	POSITIONS Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require term positions in the returned enum.

Fields inherited from class org.apache.lucene.search.DocIdSetIterator

NO_MORE_DOCS

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PostingsEnum() Sole constructor.

Method Summary

Modifier and Type	Method and Description
abstract int	endOffset() Returns end offset for the current position, or -1 if offsets were not indexed.
static boolean	featureRequested(int flags, short feature) Returns true if the given feature is requested in the flags, false otherwise.
abstract int	freq() Returns term frequency in the current document, or 1 if the field was indexed with IndexOptions.DOCS.
abstract BytesRef	getPayload() Returns the payload at this position, or null if no payload was indexed.
abstract int	nextPosition() Returns the next position, or -1 if positions were not indexed.
abstract int	startOffset() Returns start offset for the current position, or -1 if offsets were not indexed.

Methods inherited from class org.apache.lucene.search.DocIdSetIterator

advance, all, cost, docID, empty, nextDoc, range, slowAdvance

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NONE

public static final short NONE

Flag to pass to TermsEnum.postings(PostingsEnum, int) if you don't require per-document postings in the returned enum.

See Also:

Constant Field Values

FREQS

public static final short FREQS

Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require term frequencies in the returned enum.

See Also:

Constant Field Values

POSITIONS

public static final short POSITIONS

Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require term positions in the returned enum.

See Also:

Constant Field Values

OFFSETS

public static final short OFFSETS

Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require offsets in the returned enum.

See Also:

Constant Field Values

PAYLOADS

public static final short PAYLOADS

Flag to pass to TermsEnum.postings(PostingsEnum, int) if you require payloads in the returned enum.

See Also:

Constant Field Values

ALL

public static final short ALL

Flag to pass to TermsEnum.postings(PostingsEnum, int) to get positions, payloads and offsets in the returned enum

See Also:

Constant Field Values

Constructor Detail

PostingsEnum

protected PostingsEnum()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Detail

featureRequested

public static boolean featureRequested(int flags,
                                       short feature)

Returns true if the given feature is requested in the flags, false otherwise.

freq

public abstract int freq()
                  throws IOException

Returns term frequency in the current document, or 1 if the field was indexed with IndexOptions.DOCS. Do not call this before DocIdSetIterator.nextDoc() is first called, nor after DocIdSetIterator.nextDoc() returns DocIdSetIterator.NO_MORE_DOCS.

NOTE: if the PostingsEnum was obtain with NONE, the result of this method is undefined.

Throws:

IOException

nextPosition

public abstract int nextPosition()
                          throws IOException

Returns the next position, or -1 if positions were not indexed. Calling this more than freq() times is undefined.

Throws:

IOException

startOffset

public abstract int startOffset()
                         throws IOException

Returns start offset for the current position, or -1 if offsets were not indexed.

Throws:

IOException

endOffset

public abstract int endOffset()
                       throws IOException

Returns end offset for the current position, or -1 if offsets were not indexed.

Throws:

IOException

getPayload

public abstract BytesRef getPayload()
                             throws IOException

Returns the payload at this position, or null if no payload was indexed. You should not modify anything (neither members of the returned BytesRef nor bytes in the byte[]).

Throws:

IOException