org.apache.lucene.analysis
Class Token

java.lang.Object
  |
  +--org.apache.lucene.analysis.Token

public final class Token

extends Object

A Token is an occurence of a term from the text of a field. It consists of a term's text, the start and end offset of the term in the text of the field, and a type string. The start and end offsets permit applications to re-associate a token with its source text, e.g., to display highlighted query terms in a document browser, or to show matching text fragments in a KWIC (KeyWord In Context) display, etc. The type is an interned string, assigned by a lexical analyzer (a.k.a. tokenizer), naming the lexical or syntactic class that the token belongs to. For example an end of sentence marker token might be implemented with type "eos". The default token type is "word".

Constructor Summary

Token(String text, int start, int end)
Constructs a Token with the given term text, and start & end offsets.

Token(String text, int start, int end, String typ)
Constructs a Token with the given text, start and end offsets, & type.

Method Summary

int	endOffset() Returns this Token's ending offset, one greater than the position of the last character corresponding to this token in the source text.
int	startOffset() Returns this Token's starting offset, the position of the first character corresponding to this token in the source text.
String	termText() Returns the Token's term text.
String	type() Returns this Token's lexical type.

Methods inherited from class java.lang.Object

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

Constructor Detail

Token

public Token(String text,
             int start,
             int end)

Constructs a Token with the given term text, and start & end offsets. The type defaults to "word."

Token

public Token(String text,
             int start,
             int end,
             String typ)

Constructs a Token with the given text, start and end offsets, & type.

Method Detail

termText

public final String termText()

Returns the Token's term text.

startOffset

public final int startOffset()

Returns this Token's starting offset, the position of the first character corresponding to this token in the source text. Note that the difference between endOffset() and startOffset() may not be equal to termText.length(), as the term text may have been altered by a stemmer or some other filter.

endOffset

public final int endOffset()

Returns this Token's ending offset, one greater than the position of the last character corresponding to this token in the source text.

type

public final String type()

Returns this Token's lexical type. Defaults to "word".