Class MultiReader
- java.lang.Object
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- org.apache.lucene.index.IndexReader
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- org.apache.lucene.index.MultiReader
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- All Implemented Interfaces:
Closeable
,AutoCloseable
,Cloneable
- Direct Known Subclasses:
SlowMultiReaderWrapper
public class MultiReader extends IndexReader implements Cloneable
An IndexReader which reads multiple indexes, appending their content.
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.index.IndexReader
IndexReader.ReaderClosedListener
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Field Summary
Fields Modifier and Type Field Description protected int[]
starts
protected IndexReader[]
subReaders
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Fields inherited from class org.apache.lucene.index.IndexReader
hasChanges
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Constructor Summary
Constructors Constructor Description 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.
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description Object
clone()
Efficiently clones the IndexReader (sharing most internal state).IndexReader
clone(boolean openReadOnly)
Deprecated.Write support will be removed in Lucene 4.0.int
docFreq(Term t)
Returns the number of documents containing the termt
.protected void
doClose()
Implements close.protected void
doCommit(Map<String,String> commitUserData)
Deprecated.Document
document(int n, FieldSelector fieldSelector)
Get theDocument
at then
th position.protected void
doDelete(int n)
Deprecated.protected IndexReader
doOpenIfChanged()
If the index has changed since it was opened, open and return a new reader; else, returnnull
.protected IndexReader
doOpenIfChanged(boolean openReadOnly)
Deprecated.Write support will be removed in Lucene 4.0.protected void
doSetNorm(int n, String field, byte value)
Deprecated.protected void
doUndeleteAll()
Deprecated.FieldInfos
getFieldInfos()
Get theFieldInfos
describing all fields in this reader.IndexReader[]
getSequentialSubReaders()
Expert: returns the sequential sub readers that this reader is logically composed of.TermFreqVector
getTermFreqVector(int n, String field)
Return a term frequency vector for the specified document and field.void
getTermFreqVector(int docNumber, String field, TermVectorMapper mapper)
Load the Term Vector into a user-defined data structure instead of relying on the parallel arrays of theTermFreqVector
.void
getTermFreqVector(int docNumber, TermVectorMapper mapper)
Map all the term vectors for all fields in a DocumentTermFreqVector[]
getTermFreqVectors(int n)
Return an array of term frequency vectors for the specified document.long
getVersion()
Not implemented.boolean
hasDeletions()
Returns true if any documents have been deletedboolean
hasNorms(String field)
Returns true if there are norms stored for this field.boolean
isCurrent()
Checks recursively if all subreaders are up to date.boolean
isDeleted(int n)
Returns true if document n has been deletedboolean
isOptimized()
Deprecated.int
maxDoc()
Returns one greater than the largest possible document number.byte[]
norms(String field)
Returns the byte-encoded normalization factor for the named field of every document.void
norms(String field, byte[] result, int offset)
Reads the byte-encoded normalization factor for the named field of every document.int
numDocs()
Returns the number of documents in this index.protected int
readerIndex(int n)
TermDocs
termDocs()
Returns an unpositionedTermDocs
enumerator.TermDocs
termDocs(Term term)
Returns an enumeration of all the documents which containterm
.TermPositions
termPositions()
Returns an unpositionedTermPositions
enumerator.TermEnum
terms()
Returns an enumeration of all the terms in the index.TermEnum
terms(Term term)
Returns an enumeration of all terms starting at a given term.-
Methods inherited from class org.apache.lucene.index.IndexReader
acquireWriteLock, addReaderClosedListener, close, commit, commit, decRef, deleteDocument, deleteDocuments, directory, document, doOpenIfChanged, doOpenIfChanged, ensureOpen, flush, flush, getCommitUserData, getCommitUserData, getCoreCacheKey, getCurrentVersion, getDeletesCacheKey, getIndexCommit, getRefCount, getTermInfosIndexDivisor, getUniqueTermCount, incRef, indexExists, lastModified, listCommits, numDeletedDocs, open, open, open, open, open, open, open, open, open, open, open, openIfChanged, openIfChanged, openIfChanged, openIfChanged, removeReaderClosedListener, reopen, reopen, reopen, reopen, setNorm, setNorm, termPositions, toString, tryIncRef, undeleteAll
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Field Detail
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subReaders
protected final IndexReader[] subReaders
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starts
protected final int[] starts
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Constructor Detail
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MultiReader
public MultiReader(IndexReader... subReaders)
Construct a MultiReader aggregating the named set of (sub)readers. Directory locking for delete, undeleteAll, and setNorm operations is left to the subreaders.
Note that all subreaders are closed if this Multireader is closed.
- Parameters:
subReaders
- set of (sub)readers
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MultiReader
public MultiReader(IndexReader[] subReaders, boolean closeSubReaders)
Construct a MultiReader aggregating the named set of (sub)readers. Directory locking for delete, undeleteAll, and setNorm operations is left to the subreaders.
- Parameters:
closeSubReaders
- indicates whether the subreaders should be closed when this MultiReader is closedsubReaders
- set of (sub)readers
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Method Detail
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getFieldInfos
public FieldInfos getFieldInfos()
Description copied from class:IndexReader
Get theFieldInfos
describing all fields in this reader. NOTE: do not make any changes to the returned FieldInfos!- Specified by:
getFieldInfos
in classIndexReader
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doOpenIfChanged
protected IndexReader doOpenIfChanged() throws CorruptIndexException, IOException
Description copied from class:IndexReader
If the index has changed since it was opened, open and return a new reader; else, returnnull
.- Overrides:
doOpenIfChanged
in classIndexReader
- Throws:
CorruptIndexException
IOException
- See Also:
IndexReader.openIfChanged(IndexReader)
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doOpenIfChanged
@Deprecated protected IndexReader doOpenIfChanged(boolean openReadOnly) throws CorruptIndexException, IOException
Deprecated.Write support will be removed in Lucene 4.0. UsedoOpenIfChanged()
instead.Description copied from class:IndexReader
If the index has changed since it was opened, open and return a new reader; else, returnnull
.- Overrides:
doOpenIfChanged
in classIndexReader
- Throws:
UnsupportedOperationException
- MultiReaders cannot support changing the readOnly flagCorruptIndexException
IOException
- See Also:
IndexReader.openIfChanged(IndexReader, boolean)
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clone
public Object clone()
Description copied from class:IndexReader
Efficiently clones the IndexReader (sharing most internal state).On cloning a reader with pending changes (deletions, norms), the original reader transfers its write lock to the cloned reader. This means only the cloned reader may make further changes to the index, and commit the changes to the index on close, but the old reader still reflects all changes made up until it was cloned.
Like
IndexReader.openIfChanged(IndexReader)
, it's safe to make changes to either the original or the cloned reader: all shared mutable state obeys "copy on write" semantics to ensure the changes are not seen by other readers.- Overrides:
clone
in classIndexReader
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clone
@Deprecated public IndexReader clone(boolean openReadOnly) throws CorruptIndexException, IOException
Deprecated.Write support will be removed in Lucene 4.0. Useclone()
instead.Description copied from class:IndexReader
Clones the IndexReader and optionally changes readOnly. A readOnly reader cannot open a writeable reader.- Overrides:
clone
in classIndexReader
- Throws:
UnsupportedOperationException
- MultiReaders cannot support changing the readOnly flagCorruptIndexException
- if the index is corruptIOException
- if there is a low-level IO error
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getTermFreqVectors
public TermFreqVector[] getTermFreqVectors(int n) throws IOException
Description copied from class:IndexReader
Return an array of term frequency vectors for the specified document. The array contains a vector for each vectorized field in the document. Each vector contains terms and frequencies for all terms in a given vectorized field. If no such fields existed, the method returns null. The term vectors that are returned may either be of typeTermFreqVector
or of typeTermPositionVector
if positions or offsets have been stored.- Specified by:
getTermFreqVectors
in classIndexReader
- Parameters:
n
- document for which term frequency vectors are returned- Returns:
- array of term frequency vectors. May be null if no term vectors have been stored for the specified document.
- Throws:
IOException
- if index cannot be accessed- See Also:
Field.TermVector
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getTermFreqVector
public TermFreqVector getTermFreqVector(int n, String field) throws IOException
Description copied from class:IndexReader
Return a term frequency vector for the specified document and field. The returned vector contains terms and frequencies for the terms in the specified field of this document, if the field had the storeTermVector flag set. If termvectors had been stored with positions or offsets, aTermPositionVector
is returned.- Specified by:
getTermFreqVector
in classIndexReader
- Parameters:
n
- document for which the term frequency vector is returnedfield
- field for which the term frequency vector is returned.- Returns:
- term frequency vector May be null if field does not exist in the specified document or term vector was not stored.
- Throws:
IOException
- if index cannot be accessed- See Also:
Field.TermVector
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getTermFreqVector
public void getTermFreqVector(int docNumber, String field, TermVectorMapper mapper) throws IOException
Description copied from class:IndexReader
Load the Term Vector into a user-defined data structure instead of relying on the parallel arrays of theTermFreqVector
.- Specified by:
getTermFreqVector
in classIndexReader
- Parameters:
docNumber
- The number of the document to load the vector forfield
- The name of the field to loadmapper
- TheTermVectorMapper
to process the vector. Must not be null- Throws:
IOException
- if term vectors cannot be accessed or if they do not exist on the field and doc. specified.
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getTermFreqVector
public void getTermFreqVector(int docNumber, TermVectorMapper mapper) throws IOException
Description copied from class:IndexReader
Map all the term vectors for all fields in a Document- Specified by:
getTermFreqVector
in classIndexReader
- Parameters:
docNumber
- The number of the document to load the vector formapper
- TheTermVectorMapper
to process the vector. Must not be null- Throws:
IOException
- if term vectors cannot be accessed or if they do not exist on the field and doc. specified.
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isOptimized
@Deprecated public boolean isOptimized()
Deprecated.- Overrides:
isOptimized
in classIndexReader
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numDocs
public int numDocs()
Description copied from class:IndexReader
Returns the number of documents in this index.- Specified by:
numDocs
in classIndexReader
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maxDoc
public int maxDoc()
Description copied from class:IndexReader
Returns one greater than the largest possible document number. This may be used to, e.g., determine how big to allocate an array which will have an element for every document number in an index.- Specified by:
maxDoc
in classIndexReader
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document
public Document document(int n, FieldSelector fieldSelector) throws CorruptIndexException, IOException
Description copied from class:IndexReader
Get theDocument
at then
th position. TheFieldSelector
may be used to determine whatField
s to load and how they should be loaded. NOTE: If this Reader (more specifically, the underlyingFieldsReader
) is closed before the lazyField
is loaded an exception may be thrown. If you want the value of a lazyField
to be available after closing you must explicitly load it or fetch the Document again with a new loader.NOTE: for performance reasons, this method does not check if the requested document is deleted, and therefore asking for a deleted document may yield unspecified results. Usually this is not required, however you can call
IndexReader.isDeleted(int)
with the requested document ID to verify the document is not deleted.- Specified by:
document
in classIndexReader
- Parameters:
n
- Get the document at then
th positionfieldSelector
- TheFieldSelector
to use to determine what Fields should be loaded on the Document. May be null, in which case all Fields will be loaded.- Returns:
- The stored fields of the
Document
at the nth position - Throws:
CorruptIndexException
- if the index is corruptIOException
- if there is a low-level IO error- See Also:
Fieldable
,FieldSelector
,SetBasedFieldSelector
,LoadFirstFieldSelector
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isDeleted
public boolean isDeleted(int n)
Description copied from class:IndexReader
Returns true if document n has been deleted- Specified by:
isDeleted
in classIndexReader
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hasDeletions
public boolean hasDeletions()
Description copied from class:IndexReader
Returns true if any documents have been deleted- Specified by:
hasDeletions
in classIndexReader
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doDelete
@Deprecated protected void doDelete(int n) throws CorruptIndexException, IOException
Deprecated.Implements deletion of the document numbereddocNum
. Applications should callIndexReader.deleteDocument(int)
orIndexReader.deleteDocuments(Term)
.- Specified by:
doDelete
in classIndexReader
- Throws:
CorruptIndexException
IOException
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doUndeleteAll
@Deprecated protected void doUndeleteAll() throws CorruptIndexException, IOException
Deprecated.Implements actual undeleteAll() in subclass.- Specified by:
doUndeleteAll
in classIndexReader
- Throws:
CorruptIndexException
IOException
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readerIndex
protected int readerIndex(int n)
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hasNorms
public boolean hasNorms(String field) throws IOException
Description copied from class:IndexReader
Returns true if there are norms stored for this field.- Overrides:
hasNorms
in classIndexReader
- Throws:
IOException
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norms
public byte[] norms(String field) throws IOException
Description copied from class:IndexReader
Returns the byte-encoded normalization factor for the named field of every document. This is used by the search code to score documents. Returns null if norms were not indexed for this field.- Specified by:
norms
in classIndexReader
- Throws:
IOException
- See Also:
AbstractField.setBoost(float)
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norms
public void norms(String field, byte[] result, int offset) throws IOException
Description copied from class:IndexReader
Reads the byte-encoded normalization factor for the named field of every document. This is used by the search code to score documents.- Specified by:
norms
in classIndexReader
- Throws:
IOException
- See Also:
AbstractField.setBoost(float)
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doSetNorm
@Deprecated protected void doSetNorm(int n, String field, byte value) throws CorruptIndexException, IOException
Deprecated.Implements setNorm in subclass.- Specified by:
doSetNorm
in classIndexReader
- Throws:
CorruptIndexException
IOException
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terms
public TermEnum terms() throws IOException
Description copied from class:IndexReader
Returns an enumeration of all the terms in the index. The enumeration is ordered by Term.compareTo(). Each term is greater than all that precede it in the enumeration. Note that after calling terms(),TermEnum.next()
must be called on the resulting enumeration before calling other methods such asTermEnum.term()
.- Specified by:
terms
in classIndexReader
- Throws:
IOException
- if there is a low-level IO error
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terms
public TermEnum terms(Term term) throws IOException
Description copied from class:IndexReader
Returns an enumeration of all terms starting at a given term. If the given term does not exist, the enumeration is positioned at the first term greater than the supplied term. The enumeration is ordered by Term.compareTo(). Each term is greater than all that precede it in the enumeration.- Specified by:
terms
in classIndexReader
- Throws:
IOException
- if there is a low-level IO error
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docFreq
public int docFreq(Term t) throws IOException
Description copied from class:IndexReader
Returns the number of documents containing the termt
.- Specified by:
docFreq
in classIndexReader
- Throws:
IOException
- if there is a low-level IO error
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termDocs
public TermDocs termDocs() throws IOException
Description copied from class:IndexReader
Returns an unpositionedTermDocs
enumerator.Note: the TermDocs returned is unpositioned. Before using it, ensure that you first position it with
TermDocs.seek(Term)
orTermDocs.seek(TermEnum)
.- Specified by:
termDocs
in classIndexReader
- Throws:
IOException
- if there is a low-level IO error
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termDocs
public TermDocs termDocs(Term term) throws IOException
Description copied from class:IndexReader
Returns an enumeration of all the documents which containterm
. For each document, the document number, the frequency of the term in that document is also provided, for use in search scoring. If term is null, then all non-deleted docs are returned with freq=1. Thus, this method implements the mapping:-
Term => <docNum, freq>*
The enumeration is ordered by document number. Each document number is greater than all that precede it in the enumeration.
- Overrides:
termDocs
in classIndexReader
- Throws:
IOException
- if there is a low-level IO error
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termPositions
public TermPositions termPositions() throws IOException
Description copied from class:IndexReader
Returns an unpositionedTermPositions
enumerator.- Specified by:
termPositions
in classIndexReader
- Throws:
IOException
- if there is a low-level IO error
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doCommit
@Deprecated protected void doCommit(Map<String,String> commitUserData) throws IOException
Deprecated.Implements commit.- Specified by:
doCommit
in classIndexReader
- Throws:
IOException
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doClose
protected void doClose() throws IOException
Description copied from class:IndexReader
Implements close.- Specified by:
doClose
in classIndexReader
- Throws:
IOException
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isCurrent
public boolean isCurrent() throws CorruptIndexException, IOException
Checks recursively if all subreaders are up to date.- Overrides:
isCurrent
in classIndexReader
- Throws:
CorruptIndexException
- if the index is corruptIOException
- if there is a low-level IO error
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getVersion
public long getVersion()
Not implemented.- Overrides:
getVersion
in classIndexReader
- Throws:
UnsupportedOperationException
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getSequentialSubReaders
public IndexReader[] getSequentialSubReaders()
Description copied from class:IndexReader
Expert: returns the sequential sub readers that this reader is logically composed of. For example, IndexSearcher uses this API to drive searching by one sub reader at a time. If this reader is not composed of sequential child readers, it should return null. If this method returns an empty array, that means this reader is a null reader (for example a MultiReader that has no sub readers).NOTE: You should not try using sub-readers returned by this method to make any changes (setNorm, deleteDocument, etc.). While this might succeed for one composite reader (like MultiReader), it will most likely lead to index corruption for other readers (like DirectoryReader obtained through
IndexReader.open(org.apache.lucene.store.Directory)
. Use the parent reader directly.- Overrides:
getSequentialSubReaders
in classIndexReader
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