org.apache.lucene.index
Class FilterIndexReader

java.lang.Object
  extended byorg.apache.lucene.index.IndexReader
      extended byorg.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 nth 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


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