org.apache.lucene.analysis.wikipedia

Class WikipediaTokenizer

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.Tokenizer

org.apache.lucene.analysis.wikipedia.WikipediaTokenizer

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public final class WikipediaTokenizer
extends Tokenizer

Extension of StandardTokenizer that is aware of Wikipedia syntax. It is based off of the Wikipedia tutorial available at http://en.wikipedia.org/wiki/Wikipedia:Tutorial, but it may not be complete.

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
static int	ACRONYM_ID
static int	ALPHANUM_ID
static int	APOSTROPHE_ID
static java.lang.String	BOLD
static int	BOLD_ID
static java.lang.String	BOLD_ITALICS
static int	BOLD_ITALICS_ID
static int	BOTH Output the both the untokenized token and the splits
static java.lang.String	CATEGORY
static int	CATEGORY_ID
static java.lang.String	CITATION
static int	CITATION_ID
static int	CJ_ID
static int	COMPANY_ID
static int	EMAIL_ID
static java.lang.String	EXTERNAL_LINK
static int	EXTERNAL_LINK_ID
static java.lang.String	EXTERNAL_LINK_URL
static int	EXTERNAL_LINK_URL_ID
static java.lang.String	HEADING
static int	HEADING_ID
static int	HOST_ID
static java.lang.String	INTERNAL_LINK
static int	INTERNAL_LINK_ID
static java.lang.String	ITALICS
static int	ITALICS_ID
static int	NUM_ID
static java.lang.String	SUB_HEADING
static int	SUB_HEADING_ID
static java.lang.String[]	TOKEN_TYPES String token types that correspond to token type int constants
static int	TOKENS_ONLY Only output tokens
static int	UNTOKENIZED_ONLY Only output untokenized tokens, which are tokens that would normally be split into several tokens
static int	UNTOKENIZED_TOKEN_FLAG This flag is used to indicate that the produced "Token" would, if TOKENS_ONLY was used, produce multiple tokens.

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

input

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

DEFAULT_TOKEN_ATTRIBUTE_FACTORY

Constructor Summary

Constructors

Constructor and Description
WikipediaTokenizer() Creates a new instance of the WikipediaTokenizer.
WikipediaTokenizer(AttributeFactory factory, int tokenOutput, java.util.Set<java.lang.String> untokenizedTypes) Creates a new instance of the WikipediaTokenizer.
WikipediaTokenizer(int tokenOutput, java.util.Set<java.lang.String> untokenizedTypes) Creates a new instance of the WikipediaTokenizer.

Method Summary

Modifier and Type	Method and Description
void	close() Releases resources associated with this stream.
void	end() This method is called by the consumer after the last token has been consumed, after TokenStream.incrementToken() returned false (using the new TokenStream API).
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.Tokenizer

correctOffset, setReader

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

INTERNAL_LINK

public static final java.lang.String INTERNAL_LINK

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Constant Field Values

EXTERNAL_LINK

public static final java.lang.String EXTERNAL_LINK

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Constant Field Values

EXTERNAL_LINK_URL

public static final java.lang.String EXTERNAL_LINK_URL

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Constant Field Values

CITATION

public static final java.lang.String CITATION

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Constant Field Values

CATEGORY

public static final java.lang.String CATEGORY

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Constant Field Values

BOLD

public static final java.lang.String BOLD

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Constant Field Values

ITALICS

public static final java.lang.String ITALICS

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Constant Field Values

BOLD_ITALICS

public static final java.lang.String BOLD_ITALICS

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Constant Field Values

HEADING

public static final java.lang.String HEADING

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Constant Field Values

SUB_HEADING

public static final java.lang.String SUB_HEADING

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Constant Field Values

ALPHANUM_ID

public static final int ALPHANUM_ID

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Constant Field Values

APOSTROPHE_ID

public static final int APOSTROPHE_ID

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Constant Field Values

ACRONYM_ID

public static final int ACRONYM_ID

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Constant Field Values

COMPANY_ID

public static final int COMPANY_ID

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Constant Field Values

EMAIL_ID

public static final int EMAIL_ID

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Constant Field Values

HOST_ID

public static final int HOST_ID

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Constant Field Values

NUM_ID

public static final int NUM_ID

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Constant Field Values

CJ_ID

public static final int CJ_ID

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Constant Field Values

INTERNAL_LINK_ID

public static final int INTERNAL_LINK_ID

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Constant Field Values

EXTERNAL_LINK_ID

public static final int EXTERNAL_LINK_ID

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Constant Field Values

CITATION_ID

public static final int CITATION_ID

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Constant Field Values

CATEGORY_ID

public static final int CATEGORY_ID

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Constant Field Values

BOLD_ID

public static final int BOLD_ID

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Constant Field Values

ITALICS_ID

public static final int ITALICS_ID

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Constant Field Values

BOLD_ITALICS_ID

public static final int BOLD_ITALICS_ID

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Constant Field Values

HEADING_ID

public static final int HEADING_ID

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Constant Field Values

SUB_HEADING_ID

public static final int SUB_HEADING_ID

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Constant Field Values

EXTERNAL_LINK_URL_ID

public static final int EXTERNAL_LINK_URL_ID

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Constant Field Values

TOKEN_TYPES

public static final java.lang.String[] TOKEN_TYPES

String token types that correspond to token type int constants

TOKENS_ONLY

public static final int TOKENS_ONLY

Only output tokens

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Constant Field Values

UNTOKENIZED_ONLY

public static final int UNTOKENIZED_ONLY

Only output untokenized tokens, which are tokens that would normally be split into several tokens

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Constant Field Values

BOTH

public static final int BOTH

Output the both the untokenized token and the splits

See Also:

Constant Field Values

UNTOKENIZED_TOKEN_FLAG

public static final int UNTOKENIZED_TOKEN_FLAG

This flag is used to indicate that the produced "Token" would, if TOKENS_ONLY was used, produce multiple tokens.

See Also:

Constant Field Values

Constructor Detail

WikipediaTokenizer

public WikipediaTokenizer()

Creates a new instance of the WikipediaTokenizer. Attaches the input to a newly created JFlex scanner.

WikipediaTokenizer

public WikipediaTokenizer(int tokenOutput,
                          java.util.Set<java.lang.String> untokenizedTypes)

Creates a new instance of the WikipediaTokenizer. Attaches the input to a the newly created JFlex scanner.

Parameters:

tokenOutput - One of TOKENS_ONLY, UNTOKENIZED_ONLY, BOTH

WikipediaTokenizer

public WikipediaTokenizer(AttributeFactory factory,
                          int tokenOutput,
                          java.util.Set<java.lang.String> untokenizedTypes)

Creates a new instance of the WikipediaTokenizer. Attaches the input to a the newly created JFlex scanner. Uses the given AttributeFactory.

Parameters:

tokenOutput - One of TOKENS_ONLY, UNTOKENIZED_ONLY, BOTH

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

close

public void close()
           throws java.io.IOException

Description copied from class: Tokenizer

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 java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class Tokenizer

Throws:

java.io.IOException

reset

public void reset()
           throws java.io.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 Tokenizer

Throws:

java.io.IOException

end

public void end()
         throws java.io.IOException

Description copied from class: TokenStream

This method is called by the consumer after the last token has been consumed, after TokenStream.incrementToken() returned false (using the new TokenStream API). Streams implementing the old API should upgrade to use this feature.

This method can be used to perform any end-of-stream operations, such as setting the final offset of a stream. The final offset of a stream might differ from the offset of the last token eg in case one or more whitespaces followed after the last token, but a WhitespaceTokenizer was used.

Additionally any skipped positions (such as those removed by a stopfilter) can be applied to the position increment, or any adjustment of other attributes where the end-of-stream value may be important.

If you override this method, always call super.end().

Overrides:

end in class TokenStream

Throws:

java.io.IOException - If an I/O error occurs