Package org.apache.lucene.analysis.tokenattributes

Class PositionIncrementAttributeImpl

  • All Implemented Interfaces:
    Serializable, Cloneable, PositionIncrementAttribute, Attribute
    public class PositionIncrementAttributeImpl
extends AttributeImpl
implements PositionIncrementAttribute, Cloneable, Serializable
    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.
    See Also:
    Serialized Form

    • Constructor Detail

      • PositionIncrementAttributeImpl

        public PositionIncrementAttributeImpl()

    • Method Detail

      • setPositionIncrement

        public void setPositionIncrement​(int positionIncrement)
        Set the position increment. The default value is one.
        Specified by:
        setPositionIncrement in interface PositionIncrementAttribute
        Parameters:
        positionIncrement - the distance from the prior term

      • clear

        public void clear()
        Description copied from class: AttributeImpl
        Clears the values in this AttributeImpl and resets it to its default value. If this implementation implements more than one Attribute interface it clears all.
        Specified by:
        clear in class AttributeImpl

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object

      • copyTo

        public void copyTo​(AttributeImpl target)
        Description copied from class: AttributeImpl
        Copies the values from this Attribute into the passed-in target attribute. The target implementation must support all the Attributes this implementation supports.
        Specified by:
        copyTo in class AttributeImpl