Defining custom tokenizers
Although there are several excellent built-in tokenizers in Lucene, you may still find yourself needing something to behave slightly differently. You will then have to custom-build a Tokenizer. Lucene provides a character-based tokenizer called CharTokenizer
that should be suitable for most types of tokenizations. You can override its isTokenChar
method to determine what characters should be considered as part of a token and what characters should be considered as delimiters. It's worthwhile to note that both LetterTokenizer
and WhitespaceTokenizer
extend from CharTokenizer
.
How to do it…
In this example, we will create our own tokenizer that splits text by space only. It is similar to WhitespaceTokenizer
but this one ...
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