org.apache.lucene.analysis.tokenattributes

Class CharTermAttributeImpl

java.lang.Object

org.apache.lucene.util.AttributeImpl

org.apache.lucene.analysis.tokenattributes.CharTermAttributeImpl

All Implemented Interfaces:

Appendable, CharSequence, Cloneable, CharTermAttribute, TermToBytesRefAttribute, Attribute

Direct Known Subclasses:

Token

public class CharTermAttributeImpl
extends AttributeImpl
implements CharTermAttribute, TermToBytesRefAttribute, Cloneable

Default implementation of CharTermAttribute.

Constructor Summary

Constructors

Constructor and Description
CharTermAttributeImpl() Initialize this attribute with empty term text

Method Summary

Methods

Modifier and Type	Method and Description
CharTermAttribute	append(char c)
CharTermAttribute	append(CharSequence csq)
CharTermAttribute	append(CharSequence csq, int start, int end)
CharTermAttribute	append(CharTermAttribute ta) Appends the contents of the other CharTermAttribute to this character sequence.
CharTermAttribute	append(String s) Appends the specified String to this character sequence.
CharTermAttribute	append(StringBuilder s) Appends the specified StringBuilder to this character sequence.
char[]	buffer() Returns the internal termBuffer character array which you can then directly alter.
char	charAt(int index)
void	clear() Clears the values in this AttributeImpl and resets it to its default value.
CharTermAttributeImpl	clone() Shallow clone.
void	copyBuffer(char[] buffer, int offset, int length) Copies the contents of buffer, starting at offset for length characters, into the termBuffer array.
void	copyTo(AttributeImpl target) Copies the values from this Attribute into the passed-in target attribute.
boolean	equals(Object other)
int	fillBytesRef() Updates the bytes TermToBytesRefAttribute.getBytesRef() to contain this term's final encoding, and returns its hashcode.
BytesRef	getBytesRef() Retrieve this attribute's BytesRef.
int	hashCode()
int	length()
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.
char[]	resizeBuffer(int newSize) Grows the termBuffer to at least size newSize, preserving the existing content.
CharTermAttribute	setEmpty() Sets the length of the termBuffer to zero.
CharTermAttribute	setLength(int length) Set number of valid characters (length of the term) in the termBuffer array.
CharSequence	subSequence(int start, int end)
String	toString() Returns solely the term text as specified by the CharSequence interface.

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

CharTermAttributeImpl

public CharTermAttributeImpl()

Initialize this attribute with empty term text

Method Detail

copyBuffer

public final void copyBuffer(char[] buffer,
              int offset,
              int length)

Description copied from interface: CharTermAttribute

Copies the contents of buffer, starting at offset for length characters, into the termBuffer array.

Specified by:

copyBuffer in interface CharTermAttribute

Parameters:

buffer - the buffer to copy

offset - the index in the buffer of the first character to copy

length - the number of characters to copy

buffer

public final char[] buffer()

Description copied from interface: CharTermAttribute

Returns the internal termBuffer character array which you can then directly alter. If the array is too small for your token, use CharTermAttribute.resizeBuffer(int) to increase it. After altering the buffer be sure to call CharTermAttribute.setLength(int) to record the number of valid characters that were placed into the termBuffer.

NOTE: The returned buffer may be larger than the valid CharSequence.length().

Specified by:

buffer in interface CharTermAttribute

resizeBuffer

public final char[] resizeBuffer(int newSize)

Description copied from interface: CharTermAttribute

Grows the termBuffer to at least size newSize, preserving the existing content.

Specified by:

resizeBuffer in interface CharTermAttribute

Parameters:

newSize - minimum size of the new termBuffer

Returns:

newly created termBuffer with length >= newSize

setLength

public final CharTermAttribute setLength(int length)

Description copied from interface: CharTermAttribute

Set number of valid characters (length of the term) in the termBuffer array. Use this to truncate the termBuffer or to synchronize with external manipulation of the termBuffer. Note: to grow the size of the array, use CharTermAttribute.resizeBuffer(int) first.

Specified by:

setLength in interface CharTermAttribute

Parameters:

length - the truncated length

setEmpty

public final CharTermAttribute setEmpty()

Description copied from interface: CharTermAttribute

Sets the length of the termBuffer to zero. Use this method before appending contents using the Appendable interface.

Specified by:

setEmpty in interface CharTermAttribute

fillBytesRef

public int fillBytesRef()

Description copied from interface: TermToBytesRefAttribute

Updates the bytes TermToBytesRefAttribute.getBytesRef() to contain this term's final encoding, and returns its hashcode.

Specified by:

fillBytesRef in interface TermToBytesRefAttribute

Returns:

the hashcode as defined by BytesRef.hashCode():

  int hash = 0;
  for (int i = termBytes.offset; i < termBytes.offset+termBytes.length; i++) {
    hash = 31*hash + termBytes.bytes[i];
  }
 

Implement this for performance reasons, if your code can calculate the hash on-the-fly. If this is not the case, just return termBytes.hashCode().

getBytesRef

public BytesRef getBytesRef()

Description copied from interface: TermToBytesRefAttribute

Retrieve this attribute's BytesRef. The bytes are updated from the current term when the consumer calls TermToBytesRefAttribute.fillBytesRef().

Specified by:

getBytesRef in interface TermToBytesRefAttribute

Returns:

this Attributes internal BytesRef.

length

public final int length()

Specified by:

length in interface CharSequence

charAt

public final char charAt(int index)

Specified by:

charAt in interface CharSequence

subSequence

public final CharSequence subSequence(int start,
                       int end)

Specified by:

subSequence in interface CharSequence

append

public final CharTermAttribute append(CharSequence csq)

Specified by:

append in interface Appendable

Specified by:

append in interface CharTermAttribute

append

public final CharTermAttribute append(CharSequence csq,
                       int start,
                       int end)

Specified by:

append in interface Appendable

Specified by:

append in interface CharTermAttribute

append

public final CharTermAttribute append(char c)

Specified by:

append in interface Appendable

Specified by:

append in interface CharTermAttribute

append

public final CharTermAttribute append(String s)

Description copied from interface: CharTermAttribute

Appends the specified String to this character sequence.

The characters of the String argument are appended, in order, increasing the length of this sequence by the length of the argument. If argument is null, then the four characters "null" are appended.

Specified by:

append in interface CharTermAttribute

append

public final CharTermAttribute append(StringBuilder s)

Description copied from interface: CharTermAttribute

Appends the specified StringBuilder to this character sequence.

The characters of the StringBuilder argument are appended, in order, increasing the length of this sequence by the length of the argument. If argument is null, then the four characters "null" are appended.

Specified by:

append in interface CharTermAttribute

append

public final CharTermAttribute append(CharTermAttribute ta)

Description copied from interface: CharTermAttribute

Appends the contents of the other CharTermAttribute to this character sequence.

The characters of the CharTermAttribute argument are appended, in order, increasing the length of this sequence by the length of the argument. If argument is null, then the four characters "null" are appended.

Specified by:

append in interface CharTermAttribute

hashCode

public int hashCode()

Overrides:

hashCode in class Object

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

clone

public CharTermAttributeImpl clone()

Description copied from class: AttributeImpl

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

Overrides:

clone in class AttributeImpl

equals

public boolean equals(Object other)

Overrides:

equals in class Object

toString

public String toString()

Returns solely the term text as specified by the CharSequence interface.

This method changed the behavior with Lucene 3.1, before it returned a String representation of the whole term with all attributes. This affects especially the Token subclass.

Specified by:

toString in interface CharSequence

Overrides:

toString in class Object

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 AttributeImpl

See Also:

AttributeImpl.reflectAsString(boolean)

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