Lucene：中心突出显示片段中的单词

Question

是否可以使用Lucene荧光笔在突出显示的单词之前和之后使用相同数量的文本？

目前我有这个：

QueryScorer queryScorer = new QueryScorer(query, field);
Fragmenter fragmenter = new SimpleSpanFragmenter(queryScorer, frag_lenth);
SimpleHTMLFormatter htmlFormatter = new SimpleHTMLFormatter("<<<<",">>>>");
Highlighter highlighter = new Highlighter(htmlFormatter, queryScorer);
highlighter.setTextFragmenter(fragmenter); 
String text = doc.get(field);
TokenStream tokenStream = TokenSources.getAnyTokenStream(searcher.getIndexReader(), id, field, analyzer);
String high = highlighter.getBestFragments(tokenStream, text, limit_frag, " ..... ");</code>