org.apache.lucene.wikipedia.analysis
Class WikipediaTokenizer

java.lang.Object
  org.apache.lucene.analysis.TokenStream
      org.apache.lucene.analysis.Tokenizer
          org.apache.lucene.wikipedia.analysis.WikipediaTokenizer

public 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.

EXPERIMENTAL !!!!!!!!! NOTE: This Tokenizer is considered experimental and the grammar is subject to change in the trunk and in follow up releases.

Field Summary

static int	ACRONYM_ID
static int	ALPHANUM_ID
static int	APOSTROPHE_ID
static String	BOLD
static int	BOLD_ID
static String	BOLD_ITALICS
static int	BOLD_ITALICS_ID
static int	BOTH
static String	CATEGORY
static int	CATEGORY_ID
static String	CITATION
static int	CITATION_ID
static int	CJ_ID
static int	COMPANY_ID
static int	EMAIL_ID
static String	EXTERNAL_LINK
static int	EXTERNAL_LINK_ID
static String	EXTERNAL_LINK_URL
static int	EXTERNAL_LINK_URL_ID
static String	HEADING
static int	HEADING_ID
static int	HOST_ID
static String	INTERNAL_LINK
static int	INTERNAL_LINK_ID
static String	ITALICS
static int	ITALICS_ID
static int	NUM_ID
static String	SUB_HEADING
static int	SUB_HEADING_ID
static String[]	TOKEN_TYPES String token types that correspond to token type int constants
static String[]	tokenImage Deprecated. Please use TOKEN_TYPES instead
static int	TOKENS_ONLY
static int	UNTOKENIZED_ONLY
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

Constructor Summary

WikipediaTokenizer(Reader input)
Creates a new instance of the WikipediaTokenizer.

WikipediaTokenizer(Reader input, int tokenOutput, Set untokenizedTypes)

Method Summary

Token	next(Token reusableToken) Returns the next token in the stream, or null at EOS.
void	reset() Resets this stream to the beginning.
void	reset(Reader reader) Expert: Reset the tokenizer to a new reader.

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

close

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

next

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

INTERNAL_LINK

public static final String INTERNAL_LINK

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Constant Field Values

EXTERNAL_LINK

public static final String EXTERNAL_LINK

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EXTERNAL_LINK_URL

public static final String EXTERNAL_LINK_URL

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CITATION

public static final String CITATION

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CATEGORY

public static final String CATEGORY

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BOLD

public static final String BOLD

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ITALICS

public static final String ITALICS

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BOLD_ITALICS

public static final String BOLD_ITALICS

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HEADING

public static final String HEADING

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SUB_HEADING

public static final 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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COMPANY_ID

public static final int COMPANY_ID

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EMAIL_ID

public static final int EMAIL_ID

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HOST_ID

public static final int HOST_ID

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NUM_ID

public static final int NUM_ID

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CJ_ID

public static final int CJ_ID

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INTERNAL_LINK_ID

public static final int INTERNAL_LINK_ID

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EXTERNAL_LINK_ID

public static final int EXTERNAL_LINK_ID

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CITATION_ID

public static final int CITATION_ID

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CATEGORY_ID

public static final int CATEGORY_ID

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BOLD_ID

public static final int BOLD_ID

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ITALICS_ID

public static final int ITALICS_ID

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BOLD_ITALICS_ID

public static final int BOLD_ITALICS_ID

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HEADING_ID

public static final int HEADING_ID

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SUB_HEADING_ID

public static final int SUB_HEADING_ID

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EXTERNAL_LINK_URL_ID

public static final int EXTERNAL_LINK_URL_ID

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TOKEN_TYPES

public static final String[] TOKEN_TYPES

String token types that correspond to token type int constants

tokenImage

public static final String[] tokenImage

Deprecated. Please use TOKEN_TYPES instead

TOKENS_ONLY

public static final int TOKENS_ONLY

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Constant Field Values

UNTOKENIZED_ONLY

public static final int UNTOKENIZED_ONLY

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BOTH

public static final int BOTH

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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.

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Constant Field Values

Constructor Detail

WikipediaTokenizer

public WikipediaTokenizer(Reader input)

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

Parameters:

input - The Input Reader

WikipediaTokenizer

public WikipediaTokenizer(Reader input,
                          int tokenOutput,
                          Set untokenizedTypes)

Method Detail

next

public Token next(Token reusableToken)
           throws IOException

Description copied from class: TokenStream

Returns the next token in the stream, or null at EOS. When possible, the input Token should be used as the returned Token (this gives fastest tokenization performance), but this is not required and a new Token may be returned. Callers may re-use a single Token instance for successive calls to this method.

This implicitly defines a "contract" between consumers (callers of this method) and producers (implementations of this method that are the source for tokens):

• A consumer must fully consume the previously returned Token before calling this method again.
• A producer must call Token.clear() before setting the fields in it & returning it

Also, the producer must make no assumptions about a Token after it has been returned: the caller may arbitrarily change it. If the producer needs to hold onto the token for subsequent calls, it must clone() it before storing it. Note that a TokenFilter is considered a consumer.

Overrides:

next in class TokenStream

Parameters:

reusableToken - a Token that may or may not be used to return; this parameter should never be null (the callee is not required to check for null before using it, but it is a good idea to assert that it is not null.)

Returns:

next token in the stream or null if end-of-stream was hit

Throws:

IOException

reset

public void reset()
           throws IOException

Description copied from class: TokenStream

Resets this stream to the beginning. This is an optional operation, so subclasses may or may not implement this method. Reset() is not needed for the standard indexing process. However, if the Tokens of a TokenStream are intended to be consumed more than once, it is necessary to implement reset(). Note that if your TokenStream caches tokens and feeds them back again after a reset, it is imperative that you clone the tokens when you store them away (on the first pass) as well as when you return them (on future passes after reset()).

Overrides:

reset in class TokenStream

Throws:

IOException

reset

public void reset(Reader reader)
           throws IOException

Description copied from class: Tokenizer

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

Overrides:

reset in class Tokenizer

Throws:

IOException