public abstract class AtomicReader extends IndexReader
AtomicReader
is an abstract class, providing an interface for accessing an
index. Search of an index is done entirely through this abstract interface,
so that any subclass which implements it is searchable. IndexReaders implemented
by this subclass do not consist of several sub-readers,
they are atomic. They support retrieval of stored fields, doc values, terms,
and postings.
For efficiency, in this API documents are often referred to via document numbers, non-negative integers which each name a unique document in the index. These document numbers are ephemeral -- they may change as documents are added to and deleted from an index. Clients should thus not rely on a given document having the same number between sessions.
NOTE: IndexReader
instances are completely thread
safe, meaning multiple threads can call any of its methods,
concurrently. If your application requires external
synchronization, you should not synchronize on the
IndexReader
instance; use your own
(non-Lucene) objects instead.
IndexReader.ReaderClosedListener
Modifier | Constructor and Description |
---|---|
protected |
AtomicReader()
Sole constructor.
|
Modifier and Type | Method and Description |
---|---|
int |
docFreq(Term term)
Returns the number of documents containing the
term . |
abstract Fields |
fields()
Returns
Fields for this reader. |
abstract BinaryDocValues |
getBinaryDocValues(String field)
Returns
BinaryDocValues for this field, or
null if no BinaryDocValues were indexed for
this field. |
AtomicReaderContext |
getContext()
Expert: Returns the root
IndexReaderContext for this
IndexReader 's sub-reader tree. |
int |
getDocCount(String field)
Returns the number of documents that have at least one term for this field,
or -1 if this measure isn't stored by the codec.
|
abstract Bits |
getDocsWithField(String field)
Returns a
Bits at the size of reader.maxDoc() ,
with turned on bits for each docid that does have a value for this field,
or null if no DocValues were indexed for this field. |
abstract FieldInfos |
getFieldInfos()
Get the
FieldInfos describing all fields in
this reader. |
abstract Bits |
getLiveDocs()
Returns the
Bits representing live (not
deleted) docs. |
abstract NumericDocValues |
getNormValues(String field)
Returns
NumericDocValues representing norms
for this field, or null if no NumericDocValues
were indexed. |
abstract NumericDocValues |
getNumericDocValues(String field)
Returns
NumericDocValues for this field, or
null if no NumericDocValues were indexed for
this field. |
abstract SortedDocValues |
getSortedDocValues(String field)
Returns
SortedDocValues for this field, or
null if no SortedDocValues were indexed for
this field. |
abstract SortedSetDocValues |
getSortedSetDocValues(String field)
Returns
SortedSetDocValues for this field, or
null if no SortedSetDocValues were indexed for
this field. |
long |
getSumDocFreq(String field)
Returns the sum of
TermsEnum.docFreq() for all terms in this field,
or -1 if this measure isn't stored by the codec. |
long |
getSumTotalTermFreq(String field)
Returns the sum of
TermsEnum.totalTermFreq() for all terms in this
field, or -1 if this measure isn't stored by the codec (or if this fields
omits term freq and positions). |
boolean |
hasNorms(String field)
Deprecated.
(4.0) use
getFieldInfos() and check FieldInfo.hasNorms()
for the field instead. |
DocsEnum |
termDocsEnum(Term term)
Returns
DocsEnum for the specified term. |
DocsAndPositionsEnum |
termPositionsEnum(Term term)
Returns
DocsAndPositionsEnum for the specified
term. |
Terms |
terms(String field)
This may return null if the field does not exist.
|
long |
totalTermFreq(Term term)
Returns the number of documents containing the term
t . |
addReaderClosedListener, close, decRef, doClose, document, document, document, ensureOpen, equals, getCombinedCoreAndDeletesKey, getCoreCacheKey, getRefCount, getTermVector, getTermVectors, hasDeletions, hashCode, incRef, leaves, maxDoc, numDeletedDocs, numDocs, open, open, open, open, open, registerParentReader, removeReaderClosedListener, tryIncRef
protected AtomicReader()
public final AtomicReaderContext getContext()
IndexReader
IndexReaderContext
for this
IndexReader
's sub-reader tree.
Iff this reader is composed of sub
readers, i.e. this reader being a composite reader, this method returns a
CompositeReaderContext
holding the reader's direct children as well as a
view of the reader tree's atomic leaf contexts. All sub-
IndexReaderContext
instances referenced from this readers top-level
context are private to this reader and are not shared with another context
tree. For example, IndexSearcher uses this API to drive searching by one
atomic leaf reader at a time. If this reader is not composed of child
readers, this method returns an AtomicReaderContext
.
Note: Any of the sub-CompositeReaderContext
instances referenced
from this top-level context do not support CompositeReaderContext.leaves()
.
Only the top-level context maintains the convenience leaf-view
for performance reasons.
getContext
in class IndexReader
@Deprecated public final boolean hasNorms(String field) throws IOException
IOException
public abstract Fields fields() throws IOException
Fields
for this reader.
This method may return null if the reader has no
postings.IOException
public final int docFreq(Term term) throws IOException
IndexReader
term
. This method returns 0 if the term or
field does not exists. This method does not take into
account deleted documents that have not yet been merged
away.docFreq
in class IndexReader
IOException
TermsEnum.docFreq()
public final long totalTermFreq(Term term) throws IOException
t
. This method returns 0 if the term or
field does not exists. This method does not take into
account deleted documents that have not yet been merged
away.totalTermFreq
in class IndexReader
IOException
public final long getSumDocFreq(String field) throws IOException
IndexReader
TermsEnum.docFreq()
for all terms in this field,
or -1 if this measure isn't stored by the codec. Note that, just like other
term measures, this measure does not take deleted documents into account.getSumDocFreq
in class IndexReader
IOException
Terms.getSumDocFreq()
public final int getDocCount(String field) throws IOException
IndexReader
getDocCount
in class IndexReader
IOException
Terms.getDocCount()
public final long getSumTotalTermFreq(String field) throws IOException
IndexReader
TermsEnum.totalTermFreq()
for all terms in this
field, or -1 if this measure isn't stored by the codec (or if this fields
omits term freq and positions). Note that, just like other term measures,
this measure does not take deleted documents into account.getSumTotalTermFreq
in class IndexReader
IOException
Terms.getSumTotalTermFreq()
public final Terms terms(String field) throws IOException
IOException
public final DocsEnum termDocsEnum(Term term) throws IOException
DocsEnum
for the specified term.
This will return null if either the field or
term does not exist.IOException
TermsEnum.docs(Bits, DocsEnum)
public final DocsAndPositionsEnum termPositionsEnum(Term term) throws IOException
DocsAndPositionsEnum
for the specified
term. This will return null if the
field or term does not exist or positions weren't indexed.IOException
TermsEnum.docsAndPositions(Bits, DocsAndPositionsEnum)
public abstract NumericDocValues getNumericDocValues(String field) throws IOException
NumericDocValues
for this field, or
null if no NumericDocValues
were indexed for
this field. The returned instance should only be
used by a single thread.IOException
public abstract BinaryDocValues getBinaryDocValues(String field) throws IOException
BinaryDocValues
for this field, or
null if no BinaryDocValues
were indexed for
this field. The returned instance should only be
used by a single thread.IOException
public abstract SortedDocValues getSortedDocValues(String field) throws IOException
SortedDocValues
for this field, or
null if no SortedDocValues
were indexed for
this field. The returned instance should only be
used by a single thread.IOException
public abstract SortedSetDocValues getSortedSetDocValues(String field) throws IOException
SortedSetDocValues
for this field, or
null if no SortedSetDocValues
were indexed for
this field. The returned instance should only be
used by a single thread.IOException
public abstract Bits getDocsWithField(String field) throws IOException
Bits
at the size of reader.maxDoc()
,
with turned on bits for each docid that does have a value for this field,
or null if no DocValues were indexed for this field. The
returned instance should only be used by a single threadIOException
public abstract NumericDocValues getNormValues(String field) throws IOException
NumericDocValues
representing norms
for this field, or null if no NumericDocValues
were indexed. The returned instance should only be
used by a single thread.IOException
public abstract FieldInfos getFieldInfos()
FieldInfos
describing all fields in
this reader.public abstract Bits getLiveDocs()
Bits
representing live (not
deleted) docs. A set bit indicates the doc ID has not
been deleted. If this method returns null it means
there are no deleted documents (all documents are
live).
The returned instance has been safely published for
use by multiple threads without additional
synchronization.Copyright © 2000-2014 Apache Software Foundation. All Rights Reserved.