如何在lucene 5.0中使用ngram tokenizer?

时间:2015-03-17 15:28:13

标签: lucene nlp

我想为字符串生成ngram字符。下面是我用过的Lucene 4.1 lib。

    Reader reader = new StringReader(text);
    NGramTokenizer gramTokenizer = new NGramTokenizer(reader, 3, 5); //catch contiguous sequence of 3, 4 and 5 characters

    CharTermAttribute charTermAttribute = gramTokenizer.addAttribute(CharTermAttribute.class);

    while (gramTokenizer.incrementToken()) {
        String token = charTermAttribute.toString();
        System.out.println(token);}

但是,我想使用Lucene 5.0.0来实现它。 NGramTokenizer在Lucene 5.0.0中从之前的版本中发生了很大的变化,请参考http://lucene.apache.org/core/5_0_0/analyzers-common/index.html?org/apache/lucene/analysis/ngram/NGramTokenizer.html

任何人都知道如何使用Lucene 5.0.0来制作ngrams?

1 个答案:

答案 0 :(得分:3)

以下代码:

  StringReader stringReader = new StringReader("abcd");
  NGramTokenizer tokenizer = new NGramTokenizer(1, 2);
  tokenizer.setReader(stringReader);
  tokenizer.reset();
  CharTermAttribute termAtt = tokenizer.getAttribute(CharTermAttribute.class);
  while (tokenizer.incrementToken()) {
    String token = termAtt.toString();
    System.out.println(token);
  }

将产生:

a
ab
b
bc
c
cd
d