Package org.apache.lucene.analysis.compound

Class CompoundWordTokenFilterBase

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.lucene.analysis.compound.CompoundWordTokenFilterBase

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

Direct Known Subclasses:

DictionaryCompoundWordTokenFilter, HyphenationCompoundWordTokenFilter

public abstract class CompoundWordTokenFilterBase
extends TokenFilter

Base class for decomposition token filters.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	CompoundWordTokenFilterBase.CompoundToken	Helper class to hold decompounded token information

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

AttributeSource.State

Field Summary

Fields

Modifier and Type	Field	Description
private AttributeSource.State	current
static int	DEFAULT_MAX_SUBWORD_SIZE	The default for maximal length of subwords that get propagated to the output of this filter
static int	DEFAULT_MIN_SUBWORD_SIZE	The default for minimal length of subwords that get propagated to the output of this filter
static int	DEFAULT_MIN_WORD_SIZE	The default for minimal word length that gets decomposed
protected CharArraySet	dictionary
protected int	maxSubwordSize
protected int	minSubwordSize
protected int	minWordSize
protected OffsetAttribute	offsetAtt
protected boolean	onlyLongestMatch
private PositionIncrementAttribute	posIncAtt
protected CharTermAttribute	termAtt
protected java.util.LinkedList<CompoundWordTokenFilterBase.CompoundToken>	tokens

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

input

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

DEFAULT_TOKEN_ATTRIBUTE_FACTORY

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CompoundWordTokenFilterBase(TokenStream input, CharArraySet dictionary)
protected	CompoundWordTokenFilterBase(TokenStream input, CharArraySet dictionary, boolean onlyLongestMatch)
protected	CompoundWordTokenFilterBase(TokenStream input, CharArraySet dictionary, int minWordSize, int minSubwordSize, int maxSubwordSize, boolean onlyLongestMatch)

Method Summary

Modifier and Type	Method	Description
protected abstract void	decompose()	Decomposes the current termAtt and places CompoundWordTokenFilterBase.CompoundToken instances in the tokens list.
boolean	incrementToken()	Consumers (i.e., IndexWriter) use this method to advance the stream to the next token.
void	reset()	This method is called by a consumer before it begins consumption using TokenStream.incrementToken().

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

close, end

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

DEFAULT_MIN_WORD_SIZE

public static final int DEFAULT_MIN_WORD_SIZE

The default for minimal word length that gets decomposed

See Also:

Constant Field Values

DEFAULT_MIN_SUBWORD_SIZE

public static final int DEFAULT_MIN_SUBWORD_SIZE

The default for minimal length of subwords that get propagated to the output of this filter

See Also:

Constant Field Values

DEFAULT_MAX_SUBWORD_SIZE

public static final int DEFAULT_MAX_SUBWORD_SIZE

The default for maximal length of subwords that get propagated to the output of this filter

See Also:

Constant Field Values

dictionary

protected final CharArraySet dictionary

tokens

protected final java.util.LinkedList<CompoundWordTokenFilterBase.CompoundToken> tokens

minWordSize

protected final int minWordSize

minSubwordSize

protected final int minSubwordSize

maxSubwordSize

protected final int maxSubwordSize

onlyLongestMatch

protected final boolean onlyLongestMatch

termAtt

protected final CharTermAttribute termAtt

offsetAtt

protected final OffsetAttribute offsetAtt

posIncAtt

private final PositionIncrementAttribute posIncAtt

current

private AttributeSource.State current

Constructor Detail

CompoundWordTokenFilterBase

protected CompoundWordTokenFilterBase(TokenStream input,
                                      CharArraySet dictionary,
                                      boolean onlyLongestMatch)

CompoundWordTokenFilterBase

protected CompoundWordTokenFilterBase(TokenStream input,
                                      CharArraySet dictionary)

CompoundWordTokenFilterBase

protected CompoundWordTokenFilterBase(TokenStream input,
                                      CharArraySet dictionary,
                                      int minWordSize,
                                      int minSubwordSize,
                                      int maxSubwordSize,
                                      boolean onlyLongestMatch)

Method Detail

incrementToken

public final boolean incrementToken()
                             throws java.io.IOException

Description copied from class: TokenStream

Consumers (i.e., IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate AttributeImpls with the attributes of the next token.

The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use AttributeSource.captureState() to create a copy of the current attribute state.

This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to AttributeSource.addAttribute(Class) and AttributeSource.getAttribute(Class), references to all AttributeImpls that this stream uses should be retrieved during instantiation.

To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in TokenStream.incrementToken().

Specified by:

incrementToken in class TokenStream

Returns:

false for end of stream; true otherwise

Throws:

java.io.IOException

decompose

protected abstract void decompose()

Decomposes the current termAtt and places CompoundWordTokenFilterBase.CompoundToken instances in the tokens list. The original token may not be placed in the list, as it is automatically passed through this filter.

reset

public void reset()
           throws java.io.IOException

Description copied from class: TokenFilter

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).

NOTE: The default implementation chains the call to the input TokenStream, so be sure to call super.reset() when overriding this method.

Overrides:

reset in class TokenFilter

Throws:

java.io.IOException