小编why*_*ame的帖子

我试图用Lucene标记并删除txt文件中的停用词.我有这个:

public String removeStopWords(String string) throws IOException {

Set<String> stopWords = new HashSet<String>();
    stopWords.add("a");
    stopWords.add("an");
    stopWords.add("I");
    stopWords.add("the");

    TokenStream tokenStream = new StandardTokenizer(Version.LUCENE_43, new StringReader(string));
    tokenStream = new StopFilter(Version.LUCENE_43, tokenStream, stopWords);

    StringBuilder sb = new StringBuilder();

    CharTermAttribute token = tokenStream.getAttribute(CharTermAttribute.class);
    while (tokenStream.incrementToken()) {
        if (sb.length() > 0) {
            sb.append(" ");
        }
        sb.append(token.toString());
    System.out.println(sb);    
    }
    return sb.toString();
}}

我的主要看起来像这样:

    String file = "..../datatest.txt";

    TestFileReader fr = new TestFileReader();
    fr.imports(file);
    System.out.println(fr.content);

    String text = fr.content;

    Stopwords stopwords = new Stopwords();
    stopwords.removeStopWords(text);
    System.out.println(stopwords.removeStopWords(text));

这给了我一个错误,但我无法弄清楚为什么.