org.apache.lucene.index

Class TermEnum

Known Direct Subclasses:
FilteredTermEnum, FilterIndexReader.FilterTermEnum

public abstract class TermEnum
extends java.lang.Object

Abstract class for enumerating terms.

Term enumerations are always ordered by Term.compareTo(). Each term in the enumeration is greater than all that precede it.

Method Summary

abstract void
close()
Closes the enumeration to further activity, freeing resources.
abstract int
docFreq()
Returns the docFreq of the current Term in the enumeration.
abstract boolean
next()
Increments the enumeration to the next element.
boolean
skipTo(Term target)
Skips terms to the first beyond the current whose value is greater or equal to target.
abstract Term
term()
Returns the current Term in the enumeration.

Method Details

close

public abstract void close()
            throws IOException
Closes the enumeration to further activity, freeing resources.

docFreq

public abstract int docFreq()
Returns the docFreq of the current Term in the enumeration.

next

public abstract boolean next()
            throws IOException
Increments the enumeration to the next element. True if one exists.

skipTo

public boolean skipTo(Term target)
            throws IOException
Skips terms to the first beyond the current whose value is greater or equal to target.

Returns true iff there is such an entry.

Behaves as if written:

   public boolean skipTo(Term target) {
     do {
       if (!next())
 	     return false;
     } while (target > term());
     return true;
   }
 
Some implementations are considerably more efficient than that.

term

public abstract Term term()
Returns the current Term in the enumeration.

Copyright © 2000-2005 Apache Software Foundation. All Rights Reserved.