org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute |
Known Indirect Subclasses
PositionIncrementAttributeImpl |
The positionIncrement determines the position of this token
relative to the previous Token in a TokenStream , used in phrase
searching. |
Token |
A Token is an occurrence of a term from the text of a field. |
|
Class Overview
The positionIncrement determines the position of this token
relative to the previous Token in a TokenStream, used in phrase
searching.
The default value is one.
Some common uses for this are:
- Set it to zero to put multiple terms in the same position. This is
useful if, e.g., a word has multiple stems. Searches for phrases
including either stem will match. In this case, all but the first stem's
increment should be set to zero: the increment of the first instance
should be one. Repeating a token with an increment of zero can also be
used to boost the scores of matches on that token.
- Set it to values greater than one to inhibit exact phrase matches.
If, for example, one does not want phrases to match across removed stop
words, then one could build a stop word filter that removes stop words and
also sets the increment to the number of stop words removed before each
non-stop word. Then exact phrase queries will only match when the terms
occur with no intervening stop words.
Public Methods
public
abstract
int
getPositionIncrement
()
Returns the position increment of this Token.
public
abstract
void
setPositionIncrement
(int positionIncrement)
Set the position increment. The default value is one.
Parameters
positionIncrement
| the distance from the prior term
|