org.apache.lucene.index

Class TermEnum

java.lang.Object

org.apache.lucene.index.TermEnum

Direct Known 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.

Constructor Summary

Constructors

Constructor and Description
TermEnum()

Method Summary

Modifier and Type	Method and Description
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.

Methods inherited from class java.lang.Object

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

Constructor Detail

TermEnum

public TermEnum()

Method Detail

next

public abstract boolean next()
                      throws java.io.IOException

Increments the enumeration to the next element. True if one exists.

Throws:

java.io.IOException

term

public abstract Term term()

Returns the current Term in the enumeration.

docFreq

public abstract int docFreq()

Returns the docFreq of the current Term in the enumeration.

close

public abstract void close()
                    throws java.io.IOException

Closes the enumeration to further activity, freeing resources.

Throws:

java.io.IOException

skipTo

public boolean skipTo(Term target)
               throws java.io.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.

Throws:

java.io.IOException