org.apache.lucene.analysis

Class Tokenizer

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.Tokenizer

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

StandardTokenizer

public abstract class Tokenizer
extends TokenStream

A Tokenizer is a TokenStream whose input is a Reader.

This is an abstract class; subclasses must override TokenStream.incrementToken()

NOTE: Subclasses overriding TokenStream.incrementToken() must call AttributeSource.clearAttributes() before setting attributes.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

AttributeSource.State

Field Summary

Fields

Modifier and Type	Field and Description
protected Reader	input The text source for this Tokenizer.

Fields inherited from class org.apache.lucene.analysis.TokenStream

DEFAULT_TOKEN_ATTRIBUTE_FACTORY

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Tokenizer() Construct a tokenizer with no input, awaiting a call to setReader(java.io.Reader) to provide input.
protected	Tokenizer(AttributeFactory factory) Construct a tokenizer with no input, awaiting a call to setReader(java.io.Reader) to provide input.

Method Summary

Modifier and Type	Method and Description
void	close() Releases resources associated with this stream.
protected int	correctOffset(int currentOff) Return the corrected offset.
void	reset() This method is called by a consumer before it begins consumption using TokenStream.incrementToken().
void	setReader(Reader input) Expert: Set a new reader on the Tokenizer.

Methods inherited from class org.apache.lucene.analysis.TokenStream

end, incrementToken

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

addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString

Methods inherited from class java.lang.Object

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

Field Detail

input

protected Reader input

The text source for this Tokenizer.

Constructor Detail

Tokenizer

protected Tokenizer()

Construct a tokenizer with no input, awaiting a call to setReader(java.io.Reader) to provide input.

Tokenizer

protected Tokenizer(AttributeFactory factory)

Construct a tokenizer with no input, awaiting a call to setReader(java.io.Reader) to provide input.

Parameters:

factory - attribute factory.

Method Detail

close

public void close()
           throws IOException

Releases resources associated with this stream.

If you override this method, always call super.close(), otherwise some internal state will not be correctly reset (e.g., Tokenizer will throw IllegalStateException on reuse).

NOTE: The default implementation closes the input Reader, so be sure to call super.close() when overriding this method.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class TokenStream

Throws:

IOException

correctOffset

protected final int correctOffset(int currentOff)

Return the corrected offset. If input is a CharFilter subclass this method calls CharFilter.correctOffset(int), else returns currentOff.

Parameters:

currentOff - offset as seen in the output

Returns:

corrected offset based on the input

See Also:

CharFilter.correctOffset(int)

setReader

public final void setReader(Reader input)

Expert: Set a new reader on the Tokenizer. Typically, an analyzer (in its tokenStream method) will use this to re-use a previously created tokenizer.

reset

public void reset()
           throws IOException

Description copied from class: TokenStream

This method is called by a consumer before it begins consumption using TokenStream.incrementToken().

Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.

If you override this method, always call super.reset(), otherwise some internal state will not be correctly reset (e.g., Tokenizer will throw IllegalStateException on further usage).

Overrides:

reset in class TokenStream

Throws:

IOException