org.apache.lucene.index
Class FilterIndexReader

java.lang.Object
  org.apache.lucene.index.IndexReader
      org.apache.lucene.index.FilterIndexReader

public class FilterIndexReader

extends IndexReader

A FilterIndexReader contains another IndexReader, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. The class FilterIndexReader itself simply implements all abstract methods of IndexReader with versions that pass all requests to the contained index reader. Subclasses of FilterIndexReader may further override some of these methods and may also provide additional methods and fields.

Nested Class Summary

static class	FilterIndexReader.FilterTermDocs Base class for filtering TermDocs implementations.
static class	FilterIndexReader.FilterTermEnum Base class for filtering TermEnum implementations.
static class	FilterIndexReader.FilterTermPositions Base class for filtering TermPositions implementations.

Field Summary

protected IndexReader

in

Constructor Summary

FilterIndexReader(IndexReader in)

Method Summary

int	docFreq(Term t) Returns the number of documents containing the term t.
protected void	doClose() Implements close.
Document	document(int n) Returns the stored fields of the nth Document in this index.
protected void	doDelete(int n) Implements deletion of the document numbered docNum.
Collection	getFieldNames() Returns a list of all unique field names that exist in the index pointed to by this IndexReader.
Collection	getFieldNames(boolean indexed) Returns a list of all unique field names that exist in the index pointed to by this IndexReader.
boolean	hasDeletions() Returns true if any documents have been deleted
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(String f) Returns the byte-encoded normalization factor for the named field of every document.
int	numDocs() Returns the number of documents in this index.
void	setNorm(int d, String f, byte b) Expert: Resets the normalization factor for the named field of the named document.
TermDocs	termDocs() Returns an unpositioned FilterIndexReader.FilterTermDocs enumerator.
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 after a given term.
void	undeleteAll() Undeletes all documents currently marked as deleted in this index.

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

close, delete, delete, directory, finalize, getCurrentVersion, getCurrentVersion, getCurrentVersion, indexExists, indexExists, indexExists, isLocked, isLocked, lastModified, lastModified, lastModified, open, open, open, setNorm, termDocs, termPositions, unlock

Methods inherited from class java.lang.Object

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

Field Detail

in

protected IndexReader in

Constructor Detail

FilterIndexReader

public FilterIndexReader(IndexReader in)

Method Detail

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

document

public Document document(int n)
                  throws IOException

Description copied from class: IndexReader

Returns the stored fields of the n^th Document in this index.

Specified by:

document in class IndexReader

Throws:

IOException

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

hasDeletions

public boolean hasDeletions()

Description copied from class: IndexReader

Returns true if any documents have been deleted

Specified by:

hasDeletions in class IndexReader

undeleteAll

public void undeleteAll()
                 throws IOException

Description copied from class: IndexReader

Undeletes all documents currently marked as deleted in this index.

Specified by:

undeleteAll in class IndexReader

Throws:

IOException

norms

public byte[] norms(String f)
             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.

Specified by:

norms in class IndexReader

Throws:

IOException

See Also:

Field.setBoost(float)

setNorm

public void setNorm(int d,
                    String f,
                    byte b)
             throws IOException

Description copied from class: IndexReader

Expert: Resets the normalization factor for the named field of the named document. The norm represents the product of the field's boost and its length normalization. Thus, to preserve the length normalization values when resetting this, one should base the new value upon the old.

Specified by:

setNorm in class IndexReader

Throws:

IOException

See Also:

IndexReader.norms(String), Similarity.decodeNorm(byte)

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.

Specified by:

terms in class IndexReader

Throws:

IOException

terms

public TermEnum terms(Term t)
               throws IOException

Description copied from class: IndexReader

Returns an enumeration of all terms after a given 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:

IOException

docFreq

public int docFreq(Term t)
            throws IOException

Description copied from class: IndexReader

Returns the number of documents containing the term t.

Specified by:

docFreq in class IndexReader

Throws:

IOException

termDocs

public TermDocs termDocs()
                  throws IOException

Description copied from class: IndexReader

Returns an unpositioned TermDocs enumerator.

Specified by:

termDocs in class IndexReader

Throws:

IOException

termPositions

public TermPositions termPositions()
                            throws IOException

Description copied from class: IndexReader

Returns an unpositioned TermPositions enumerator.

Specified by:

termPositions in class IndexReader

Throws:

IOException

doDelete

protected void doDelete(int n)
                 throws IOException

Description copied from class: IndexReader

Implements deletion of the document numbered docNum. Applications should call IndexReader.delete(int) or IndexReader.delete(Term).

Specified by:

doDelete in class IndexReader

Throws:

IOException

doClose

protected void doClose()
                throws IOException

Description copied from class: IndexReader

Implements close.

Specified by:

doClose in class IndexReader

Throws:

IOException

getFieldNames

public Collection getFieldNames()
                         throws IOException

Description copied from class: IndexReader

Returns a list of all unique field names that exist in the index pointed to by this IndexReader.

Specified by:

getFieldNames in class IndexReader

Returns:

Collection of Strings indicating the names of the fields

Throws:

IOException - if there is a problem with accessing the index

getFieldNames

public Collection getFieldNames(boolean indexed)
                         throws IOException

Description copied from class: IndexReader

Returns a list of all unique field names that exist in the index pointed to by this IndexReader. The boolean argument specifies whether the fields returned are indexed or not.

Specified by:

getFieldNames in class IndexReader

Parameters:

indexed - true if only indexed fields should be returned; false if only unindexed fields should be returned.

Returns:

Collection of Strings indicating the names of the fields

Throws:

IOException - if there is a problem with accessing the index