org.apache.lucene.analysis.tokenattributes

Class PackedTokenAttributeImpl

java.lang.Object

org.apache.lucene.util.AttributeImpl

org.apache.lucene.analysis.tokenattributes.CharTermAttributeImpl

org.apache.lucene.analysis.tokenattributes.PackedTokenAttributeImpl

All Implemented Interfaces:

Appendable, CharSequence, Cloneable, CharTermAttribute, OffsetAttribute, PositionIncrementAttribute, PositionLengthAttribute, TermToBytesRefAttribute, TypeAttribute, Attribute

Direct Known Subclasses:

Token

public class PackedTokenAttributeImpl
extends CharTermAttributeImpl
implements TypeAttribute, PositionIncrementAttribute, PositionLengthAttribute, OffsetAttribute

Default implementation of the common attributes used by Lucene:

• CharTermAttribute
• TypeAttribute
• PositionIncrementAttribute
• PositionLengthAttribute
• OffsetAttribute

Field Summary

Fields inherited from interface org.apache.lucene.analysis.tokenattributes.TypeAttribute

DEFAULT_TYPE

Constructor Summary

Constructors

Constructor and Description
PackedTokenAttributeImpl() Constructs the attribute implementation.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Resets the attributes
PackedTokenAttributeImpl	clone() Shallow clone.
void	copyTo(AttributeImpl target) Copies the values from this Attribute into the passed-in target attribute.
int	endOffset() Returns this Token's ending offset, one greater than the position of the last character corresponding to this token in the source text.
boolean	equals(Object obj)
int	getPositionIncrement() Returns the position increment of this Token.
int	getPositionLength() Returns the position length of this Token.
int	hashCode()
void	reflectWith(AttributeReflector reflector) This method is for introspection of attributes, it should simply add the key/values this attribute holds to the given AttributeReflector.
void	setOffset(int startOffset, int endOffset) Set the starting and ending offset.
void	setPositionIncrement(int positionIncrement) Set the position increment.
void	setPositionLength(int positionLength) Set the position length of this Token.
void	setType(String type) Set the lexical type.
int	startOffset() Returns this Token's starting offset, the position of the first character corresponding to this token in the source text.
String	type() Returns this Token's lexical type.

Methods inherited from class org.apache.lucene.analysis.tokenattributes.CharTermAttributeImpl

append, append, append, append, append, append, buffer, charAt, copyBuffer, fillBytesRef, getBytesRef, length, resizeBuffer, setEmpty, setLength, subSequence, toString

Methods inherited from class org.apache.lucene.util.AttributeImpl

reflectAsString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

PackedTokenAttributeImpl

public PackedTokenAttributeImpl()

Constructs the attribute implementation.

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

See Also:

PositionIncrementAttribute

getPositionIncrement

public int getPositionIncrement()

Returns the position increment of this Token.

Specified by:

getPositionIncrement in interface PositionIncrementAttribute

See Also:

PositionIncrementAttribute

setPositionLength

public void setPositionLength(int positionLength)

Set the position length of this Token.

The default value is one.

Specified by:

setPositionLength in interface PositionLengthAttribute

Parameters:

positionLength - how many positions this token spans.

See Also:

PositionLengthAttribute

getPositionLength

public int getPositionLength()

Returns the position length of this Token.

Specified by:

getPositionLength in interface PositionLengthAttribute

See Also:

PositionLengthAttribute

startOffset

public final int startOffset()

Returns this Token's starting offset, the position of the first character corresponding to this token in the source text.

Note that the difference between OffsetAttribute.endOffset() and startOffset() may not be equal to termText.length(), as the term text may have been altered by a stemmer or some other filter.

Specified by:

startOffset in interface OffsetAttribute

See Also:

OffsetAttribute

endOffset

public final int endOffset()

Returns this Token's ending offset, one greater than the position of the last character corresponding to this token in the source text. The length of the token in the source text is (endOffset() - OffsetAttribute.startOffset()).

Specified by:

endOffset in interface OffsetAttribute

See Also:

OffsetAttribute

setOffset

public void setOffset(int startOffset,
             int endOffset)

Set the starting and ending offset.

Specified by:

setOffset in interface OffsetAttribute

See Also:

OffsetAttribute

type

public final String type()

Returns this Token's lexical type. Defaults to "word".

Specified by:

type in interface TypeAttribute

See Also:

TypeAttribute

setType

public final void setType(String type)

Set the lexical type.

Specified by:

setType in interface TypeAttribute

See Also:

TypeAttribute

clear

public void clear()

Resets the attributes

Overrides:

clear in class CharTermAttributeImpl

clone

public PackedTokenAttributeImpl clone()

Description copied from class: AttributeImpl

Shallow clone. Subclasses must override this if they need to clone any members deeply,

Overrides:

clone in class CharTermAttributeImpl

equals

public boolean equals(Object obj)

Overrides:

equals in class CharTermAttributeImpl

hashCode

public int hashCode()

Overrides:

hashCode in class CharTermAttributeImpl

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.

Overrides:

copyTo in class CharTermAttributeImpl

reflectWith

public void reflectWith(AttributeReflector reflector)

Description copied from class: AttributeImpl

This method is for introspection of attributes, it should simply add the key/values this attribute holds to the given AttributeReflector.

The default implementation calls AttributeReflector.reflect(java.lang.Class<? extends org.apache.lucene.util.Attribute>, java.lang.String, java.lang.Object) for all non-static fields from the implementing class, using the field name as key and the field value as value. The Attribute class is also determined by reflection. Please note that the default implementation can only handle single-Attribute implementations.

Custom implementations look like this (e.g. for a combined attribute implementation):

   public void reflectWith(AttributeReflector reflector) {
     reflector.reflect(CharTermAttribute.class, "term", term());
     reflector.reflect(PositionIncrementAttribute.class, "positionIncrement", getPositionIncrement());
   }
 

If you implement this method, make sure that for each invocation, the same set of Attribute interfaces and keys are passed to AttributeReflector.reflect(java.lang.Class<? extends org.apache.lucene.util.Attribute>, java.lang.String, java.lang.Object) in the same order, but possibly different values. So don't automatically exclude e.g. null properties!

Overrides:

reflectWith in class CharTermAttributeImpl

See Also:

AttributeImpl.reflectAsString(boolean)