用lucene模糊搜索 [英] fuzzy search with lucene

问题描述

我用lucene 4.3.1实现了模糊搜索，但是我对结果并不满意。我想指定一些它应该返回的结果。例如，如果我想要10个结果，它应该返回10个最好的匹配，不管它们有多糟糕。大多数情况下，如果我搜索的单词与索引中的任何单词都非常不同，它将不会返回任何内容。如何获得更多/更模糊的结果？

这里的代码我有：

  public String [] luceneQuery（String query，int numberOfHits，String path）
 throws ParseException，IOException {
 
 File dir = new File（path）; 
目录索引= FSDirectory.open（dir）; 
 
 query = query +〜; 
 Query q = new QueryParser（Version.LUCENE_43，label，analyzer）
 .parse（query）; 
 
 IndexReader reader = DirectoryReader.open（index）; 
 IndexSearcher搜索者=新的IndexSearcher（读者）; 
 
 Query fuzzyQuery = new FuzzyQuery（new Term（label，query），2）; 
 
 ScoreDoc [] fuzzyHits = searcher.search（fuzzyQuery，numberOfHits）.scoreDocs; 
 String [] fuzzyResults = new String [fuzzyHits.length]; 
 
 for（int i = 0; i< fuzzyHits.length; ++ i）{
 int docId = fuzzyHits [i] .doc; 
文档d = searcher.doc（docId）; 
 fuzzyResults [i] = d.get（label）; 
} 
 
 reader.close（）; 
返回fuzzyResults; 
} 
  

解决方案

在Lucene 4.x中由 FuzzyQuery 支持。目前 FuzzyQuery 的实现对Lucene 3.x实现的性能有很大的改进，但只支持两个编辑。根据 /4_0_0/core/org/apache/lucene/search/FuzzyQuery.htmlrel =nofollow> FuzzyQuery 文档，如果您确实必须拥有更高的编辑距离：

如果您真的想要这样，请考虑使用n-gram索引技术（例如，建议模块中的SpellChecker）。

强烈的含义是您应该重新思考您想要完成的事情，并找到更有用的方法。 $ b

I implemented a fuzzy search with lucene 4.3.1 but i'm not satisfied with the result. I would like to specify a number of results it should return. So for example if I want 10 results, it should return the 10 best matches, no matter how bad they are. Most of the time it returns nothing if the word I search for is very different from anything in the index. How can I achieve more/fuzzier results?

Here the code I have:

    public String[] luceneQuery(String query, int numberOfHits, String path)
        throws ParseException, IOException {

    File dir = new File(path);
    Directory index = FSDirectory.open(dir);

    query = query + "~";
    Query q = new QueryParser(Version.LUCENE_43, "label", analyzer)
            .parse(query);

    IndexReader reader = DirectoryReader.open(index);
    IndexSearcher searcher = new IndexSearcher(reader);

    Query fuzzyQuery = new FuzzyQuery(new Term("label", query), 2);

    ScoreDoc[] fuzzyHits = searcher.search(fuzzyQuery, numberOfHits).scoreDocs;
    String[] fuzzyResults = new String[fuzzyHits.length];

    for (int i = 0; i < fuzzyHits.length; ++i) {
        int docId = fuzzyHits[i].doc;
        Document d = searcher.doc(docId);
        fuzzyResults[i] = d.get("label");
    }

    reader.close();
    return fuzzyResults;
}

解决方案

large edit distances are no longer supported by FuzzyQuery in Lucene 4.x. The current implementation of FuzzyQuery is a huge improvement on performance from the Lucene 3.x implementation, but only supports two edits. Distances greater than 2 Damerau–Levenshtein edits are considered to rarely be really useful.

According to the FuzzyQuery documentation, if you really must have higher edit distances:

If you really want this, consider using an n-gram indexing technique (such as the SpellChecker in the suggest module) instead.

The strong implication is that you should rethink what your trying to accomplish, and find a more useful approach.

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