SegmentReader (Lucene 2.9.4 API)

java.lang.Object
- org.apache.lucene.index.IndexReader
- - org.apache.lucene.index.SegmentReader

All Implemented Interfaces:

java.lang.Cloneable
```
public class SegmentReader
extends IndexReader
implements java.lang.Cloneable
```
NOTE: This API is new and still experimental (subject to change suddenly in the next release)

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.lucene.index.IndexReader
  IndexReader.FieldOption

Field Summary

Fields
Modifier and Type Field and Description

protected boolean readOnly
- Fields inherited from class org.apache.lucene.index.IndexReader
  hasChanges

Fields
Modifier and Type	Field and Description
`protected boolean`	`readOnly`

Constructor Summary

Constructors
Constructor and Description

SegmentReader()

Constructors
Constructor and Description
`SegmentReader()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`java.lang.Object`	`clone()` Efficiently clones the IndexReader (sharing most internal state).
`IndexReader`	`clone(boolean openReadOnly)` Clones the IndexReader and optionally changes readOnly.
`protected BitVector`	`cloneDeletedDocs(BitVector bv)` Clones the deleteDocs BitVector.
`protected byte[]`	`cloneNormBytes(byte[] bytes)` Clones the norm bytes.
`Directory`	`directory()` Returns the directory this index resides in.
`int`	`docFreq(Term t)` Returns the number of documents containing the term `t`.
`protected void`	`doClose()` Implements close.
`protected void`	`doCommit()` Deprecated.
`protected void`	`doCommit(java.util.Map commitUserData)` Implements commit.
`Document`	`document(int n, FieldSelector fieldSelector)` Get the `Document` at the `n` ^th position.
`protected void`	`doDelete(int docNum)` Implements deletion of the document numbered `docNum`.
`protected void`	`doSetNorm(int doc, java.lang.String field, byte value)` Implements setNorm in subclass.
`protected void`	`doUndeleteAll()` Implements actual undeleteAll() in subclass.
`static SegmentReader`	`get(boolean readOnly, Directory dir, SegmentInfo si, int readBufferSize, boolean doOpenStores, int termInfosIndexDivisor)`
`static SegmentReader`	`get(boolean readOnly, SegmentInfo si, int termInfosIndexDivisor)`
`static SegmentReader`	`get(SegmentInfo si)` Deprecated.
`java.lang.Object`	`getDeletesCacheKey()` Expert.
`java.lang.Object`	`getFieldCacheKey()` Expert
`java.util.Collection`	`getFieldNames(IndexReader.FieldOption fieldOption)` Get a list of unique field names that exist in this index and have the specified field option information.
`protected byte[]`	`getNorms(java.lang.String field)`
`java.lang.String`	`getSegmentName()` Return the name of the segment this reader is reading.
`TermFreqVector`	`getTermFreqVector(int docNumber, java.lang.String field)` Return a term frequency vector for the specified document and field.
`void`	`getTermFreqVector(int docNumber, java.lang.String field, TermVectorMapper mapper)` Load the Term Vector into a user-defined data structure instead of relying on the parallel arrays of the `TermFreqVector`.
`void`	`getTermFreqVector(int docNumber, TermVectorMapper mapper)` Map all the term vectors for all fields in a Document
`TermFreqVector[]`	`getTermFreqVectors(int docNumber)` Return an array of term frequency vectors for the specified document.
`int`	`getTermInfosIndexDivisor()` For IndexReader implementations that use TermInfosReader to read terms, this returns the current indexDivisor as specified when the reader was opened.
`long`	`getUniqueTermCount()` Returns the number of unique terms (across all fields) in this reader.
`boolean`	`hasDeletions()` Returns true if any documents have been deleted
`boolean`	`hasNorms(java.lang.String field)` Returns true if there are norms stored for this field.
`boolean`	`isDeleted(int n)` Returns true if document n has been deleted
`int`	`maxDoc()` Returns one greater than the largest possible document number.
`byte[]`	`norms(java.lang.String field)` Returns the byte-encoded normalization factor for the named field of every document.
`void`	`norms(java.lang.String field, byte[] bytes, int offset)` Read norms into a pre-allocated array.
`int`	`numDocs()` Returns the number of documents in this index.
`TermDocs`	`termDocs()` Returns an unpositioned `TermDocs` enumerator.
`TermDocs`	`termDocs(Term term)` Returns an enumeration of all the documents which contain `term`.
`TermPositions`	`termPositions()` Returns an unpositioned `TermPositions` enumerator.
`TermEnum`	`terms()` Returns an enumeration of all the terms in the index.
`TermEnum`	`terms(Term t)` Returns an enumeration of all terms starting at a given term.

Methods inherited from class org.apache.lucene.index.IndexReader
acquireWriteLock, close, commit, commit, decRef, deleteDocument, deleteDocuments, document, ensureOpen, flush, flush, getCommitUserData, getCommitUserData, getCurrentVersion, getCurrentVersion, getCurrentVersion, getDisableFakeNorms, getIndexCommit, getRefCount, getSequentialSubReaders, getVersion, incRef, indexExists, indexExists, indexExists, isCurrent, isLocked, isLocked, isOptimized, lastModified, lastModified, lastModified, listCommits, main, numDeletedDocs, open, open, open, open, open, open, open, open, open, open, open, open, open, open, reopen, reopen, reopen, setDisableFakeNorms, setNorm, setNorm, setTermInfosIndexDivisor, termPositions, undeleteAll, unlock

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - readOnly
```
protected boolean readOnly
```
- Constructor Detail
  - SegmentReader
```
public SegmentReader()
```
- Method Detail
  - get
```
public static SegmentReader get(SegmentInfo si)
                         throws CorruptIndexException,
                                java.io.IOException
```
    Deprecated.
    
    Throws:
    
    CorruptIndexException - if the index is corrupt
    
    java.io.IOException - if there is a low-level IO error
  - get
```
public static SegmentReader get(boolean readOnly,
                                SegmentInfo si,
                                int termInfosIndexDivisor)
                         throws CorruptIndexException,
                                java.io.IOException
```
    Throws:
    
    CorruptIndexException - if the index is corrupt
    
    java.io.IOException - if there is a low-level IO error
  - get
```
public static SegmentReader get(boolean readOnly,
                                Directory dir,
                                SegmentInfo si,
                                int readBufferSize,
                                boolean doOpenStores,
                                int termInfosIndexDivisor)
                         throws CorruptIndexException,
                                java.io.IOException
```
    Throws:
    
    CorruptIndexException - if the index is corrupt
    
    java.io.IOException - if there is a low-level IO error
  - cloneNormBytes
```
protected byte[] cloneNormBytes(byte[] bytes)
```
    Clones the norm bytes. May be overridden by subclasses. New and experimental.
    
    Parameters:
    
    bytes - Byte array to clone
    
    Returns:
    
    New BitVector
  - cloneDeletedDocs
```
protected BitVector cloneDeletedDocs(BitVector bv)
```
    Clones the deleteDocs BitVector. May be overridden by subclasses. New and experimental.
    
    Parameters:
    
    bv - BitVector to clone
    
    Returns:
    
    New BitVector
  - clone
```
public final java.lang.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.reopen(), 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 class IndexReader
  - clone
```
public final IndexReader clone(boolean openReadOnly)
                        throws CorruptIndexException,
                               java.io.IOException
```
    Description copied from class: IndexReader
    
    Clones the IndexReader and optionally changes readOnly. A readOnly reader cannot open a writeable reader.
    
    Overrides:
    
    clone in class IndexReader
    
    Throws:
    
    CorruptIndexException - if the index is corrupt
    
    java.io.IOException - if there is a low-level IO error
  - doCommit
```
protected void doCommit()
                 throws java.io.IOException
```
    Deprecated.
    
    Description copied from class: IndexReader
    
    Implements commit.
    
    Specified by:
    
    doCommit in class IndexReader
    
    Throws:
    
    java.io.IOException
  - doCommit
```
protected void doCommit(java.util.Map commitUserData)
                 throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Implements commit. NOTE: subclasses should override this. In 3.0 this will become an abstract method.
    
    Throws:
    
    java.io.IOException
  - doClose
```
protected void doClose()
                throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Implements close.
    
    Specified by:
    
    doClose in class IndexReader
    
    Throws:
    
    java.io.IOException
  - hasDeletions
```
public boolean hasDeletions()
```
    Description copied from class: IndexReader
    
    Returns true if any documents have been deleted
    
    Specified by:
    
    hasDeletions in class IndexReader
  - doDelete
```
protected void doDelete(int docNum)
```
    Description copied from class: IndexReader
    
    Implements deletion of the document numbered docNum. Applications should call IndexReader.deleteDocument(int) or IndexReader.deleteDocuments(Term).
    
    Specified by:
    
    doDelete in class IndexReader
  - doUndeleteAll
```
protected void doUndeleteAll()
```
    Description copied from class: IndexReader
    
    Implements actual undeleteAll() in subclass.
    
    Specified by:
    
    doUndeleteAll in class IndexReader
  - terms
```
public TermEnum terms()
```
    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 as TermEnum.term().
    
    Specified by:
    
    terms in class IndexReader
  - terms
```
public TermEnum terms(Term t)
               throws java.io.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 class IndexReader
    
    Throws:
    
    java.io.IOException - if there is a low-level IO error
  - document
```
public Document document(int n,
                         FieldSelector fieldSelector)
                  throws CorruptIndexException,
                         java.io.IOException
```
    Description copied from class: IndexReader
    
    Get the Document at the n ^th position. The FieldSelector may be used to determine what Fields to load and how they should be loaded. NOTE: If this Reader (more specifically, the underlying FieldsReader) is closed before the lazy Field is loaded an exception may be thrown. If you want the value of a lazy Field 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 class IndexReader
    
    Parameters:
    
    n - Get the document at the n^th position
    
    fieldSelector - The FieldSelector 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 corrupt
    
    java.io.IOException - if there is a low-level IO error
    
    See Also:
    
    Fieldable, FieldSelector, SetBasedFieldSelector, LoadFirstFieldSelector
  - isDeleted
```
public boolean isDeleted(int n)
```
    Description copied from class: IndexReader
    
    Returns true if document n has been deleted
    
    Specified by:
    
    isDeleted in class IndexReader
  - termDocs
```
public TermDocs termDocs(Term term)
                  throws java.io.IOException
```
    Description copied from class: IndexReader
    Returns an enumeration of all the documents which contain term. 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:
    The enumeration is ordered by document number. Each document number is greater than all that precede it in the enumeration.
    Overrides:
    
    termDocs in class IndexReader
    
    Throws:
    
    java.io.IOException - if there is a low-level IO error
  - termDocs
```
public TermDocs termDocs()
                  throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Returns an unpositioned TermDocs enumerator.
    
    Specified by:
    
    termDocs in class IndexReader
    
    Throws:
    
    java.io.IOException - if there is a low-level IO error
  - termPositions
```
public TermPositions termPositions()
                            throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Returns an unpositioned TermPositions enumerator.
    
    Specified by:
    
    termPositions in class IndexReader
    
    Throws:
    
    java.io.IOException - if there is a low-level IO error
  - docFreq
```
public int docFreq(Term t)
            throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Returns the number of documents containing the term t.
    
    Specified by:
    
    docFreq in class IndexReader
    
    Throws:
    
    java.io.IOException - if there is a low-level IO error
  - numDocs
```
public int numDocs()
```
    Description copied from class: IndexReader
    
    Returns the number of documents in this index.
    
    Specified by:
    
    numDocs in class IndexReader
  - 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 class IndexReader
  - getFieldNames
```
public java.util.Collection getFieldNames(IndexReader.FieldOption fieldOption)
```
    Description copied from class: IndexReader
    
    Get a list of unique field names that exist in this index and have the specified field option information.
    
    Specified by:
    
    getFieldNames in class IndexReader
    
    Parameters:
    
    fieldOption - specifies which field option should be available for the returned fields
    
    Returns:
    
    Collection of Strings indicating the names of the fields.
    
    See Also:
    
    IndexReader.getFieldNames(org.apache.lucene.index.IndexReader.FieldOption)
  - hasNorms
```
public boolean hasNorms(java.lang.String field)
```
    Description copied from class: IndexReader
    
    Returns true if there are norms stored for this field.
    
    Overrides:
    
    hasNorms in class IndexReader
  - getNorms
```
protected byte[] getNorms(java.lang.String field)
                   throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - norms
```
public byte[] norms(java.lang.String field)
             throws java.io.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.
    
    Specified by:
    
    norms in class IndexReader
    
    Throws:
    
    java.io.IOException
    
    See Also:
    
    AbstractField.setBoost(float)
  - doSetNorm
```
protected void doSetNorm(int doc,
                         java.lang.String field,
                         byte value)
                  throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Implements setNorm in subclass.
    
    Specified by:
    
    doSetNorm in class IndexReader
    
    Throws:
    
    java.io.IOException
  - norms
```
public void norms(java.lang.String field,
                  byte[] bytes,
                  int offset)
           throws java.io.IOException
```
    Read norms into a pre-allocated array.
    
    Specified by:
    
    norms in class IndexReader
    
    Throws:
    
    java.io.IOException
    
    See Also:
    
    AbstractField.setBoost(float)
  - getTermFreqVector
```
public TermFreqVector getTermFreqVector(int docNumber,
                                        java.lang.String field)
                                 throws java.io.IOException
```
    Return a term frequency vector for the specified document and field. The vector returned contains term numbers and frequencies for all terms in the specified field of this document, if the field had storeTermVector flag set. If the flag was not set, the method returns null.
    
    Specified by:
    
    getTermFreqVector in class IndexReader
    
    Parameters:
    
    docNumber - document for which the term frequency vector is returned
    
    field - 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:
    
    java.io.IOException
    
    See Also:
    
    Field.TermVector
  - getTermFreqVector
```
public void getTermFreqVector(int docNumber,
                              java.lang.String field,
                              TermVectorMapper mapper)
                       throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Load the Term Vector into a user-defined data structure instead of relying on the parallel arrays of the TermFreqVector.
    
    Specified by:
    
    getTermFreqVector in class IndexReader
    
    Parameters:
    
    docNumber - The number of the document to load the vector for
    
    field - The name of the field to load
    
    mapper - The TermVectorMapper to process the vector. Must not be null
    
    Throws:
    
    java.io.IOException - if term vectors cannot be accessed or if they do not exist on the field and doc. specified.
  - getTermFreqVector
```
public void getTermFreqVector(int docNumber,
                              TermVectorMapper mapper)
                       throws java.io.IOException
```
    Description copied from class: IndexReader
    
    Map all the term vectors for all fields in a Document
    
    Specified by:
    
    getTermFreqVector in class IndexReader
    
    Parameters:
    
    docNumber - The number of the document to load the vector for
    
    mapper - The TermVectorMapper to process the vector. Must not be null
    
    Throws:
    
    java.io.IOException - if term vectors cannot be accessed or if they do not exist on the field and doc. specified.
  - getTermFreqVectors
```
public TermFreqVector[] getTermFreqVectors(int docNumber)
                                    throws java.io.IOException
```
    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 vector contains term numbers and frequencies for all terms in a given vectorized field. If no such fields existed, the method returns null.
    
    Specified by:
    
    getTermFreqVectors in class IndexReader
    
    Parameters:
    
    docNumber - 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:
    
    java.io.IOException
    
    See Also:
    
    Field.TermVector
  - getSegmentName
```
public java.lang.String getSegmentName()
```
    Return the name of the segment this reader is reading.
  - directory
```
public Directory directory()
```
    Returns the directory this index resides in.
    
    Overrides:
    
    directory in class IndexReader
  - getFieldCacheKey
```
public final java.lang.Object getFieldCacheKey()
```
    Description copied from class: IndexReader
    
    Expert
    
    Overrides:
    
    getFieldCacheKey in class IndexReader
  - getDeletesCacheKey
```
public java.lang.Object getDeletesCacheKey()
```
    Description copied from class: IndexReader
    
    Expert. Warning: this returns null if the reader has no deletions
    
    Overrides:
    
    getDeletesCacheKey in class IndexReader
  - getUniqueTermCount
```
public long getUniqueTermCount()
```
    Description copied from class: IndexReader
    
    Returns the number of unique terms (across all fields) in this reader. This method returns long, even though internally Lucene cannot handle more than 2^31 unique terms, for a possible future when this limitation is removed.
    
    Overrides:
    
    getUniqueTermCount in class IndexReader
  - getTermInfosIndexDivisor
```
public int getTermInfosIndexDivisor()
```
    Description copied from class: IndexReader
    
    For IndexReader implementations that use TermInfosReader to read terms, this returns the current indexDivisor as specified when the reader was opened.
    
    Overrides:
    
    getTermInfosIndexDivisor in class IndexReader

Class SegmentReader

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.index.IndexReader

Field Summary

Fields inherited from class org.apache.lucene.index.IndexReader

Constructor Summary

Method Summary

Methods inherited from class org.apache.lucene.index.IndexReader

Methods inherited from class java.lang.Object

Field Detail

readOnly

Constructor Detail

SegmentReader

Method Detail

get

get

get

cloneNormBytes

cloneDeletedDocs

clone

clone

doCommit

doCommit

doClose

hasDeletions

doDelete

doUndeleteAll

terms

terms

document

isDeleted

termDocs

termDocs

termPositions

docFreq

numDocs

maxDoc

getFieldNames

hasNorms

getNorms

norms

doSetNorm

norms

getTermFreqVector

getTermFreqVector

getTermFreqVector

getTermFreqVectors

getSegmentName

directory

getFieldCacheKey

getDeletesCacheKey

getUniqueTermCount

getTermInfosIndexDivisor