Lucene 4.0中的术语向量频率 [英] Term Vector Frequency in Lucene 4.0

问题描述

我正在从Lucene 3.6升级到Lucene 4.0-beta.在Lucene 3.x中，IndexReader包含方法IndexReader.getTermFreqVectors()，我可以使用该方法提取给定文档和字段中每个术语的频率.

I'm upgrading from Lucene 3.6 to Lucene 4.0-beta. In Lucene 3.x, the IndexReader contains a method IndexReader.getTermFreqVectors(), which I can use to extract the frequency of each term in a given document and field.

此方法现在由IndexReader.getTermVectors()代替，该方法返回Terms.如何利用这种(或可能的其他方法)提取文档和字段中的术语频率?

This method is now replaced by IndexReader.getTermVectors(), which returns Terms. How can I make use of this (or probably other methods) to extract the term frequency in a document and a field?

推荐答案

也许这会帮助您:

// get terms vectors for one document and one field
Terms terms = reader.getTermVector(docID, "fieldName"); 

if (terms != null && terms.size() > 0) {
    // access the terms for this field
    TermsEnum termsEnum = terms.iterator(null); 
    BytesRef term = null;

    // explore the terms for this field
    while ((term = termsEnum.next()) != null) {
        // enumerate through documents, in this case only one
        DocsEnum docsEnum = termsEnum.docs(null, null); 
        int docIdEnum;
        while ((docIdEnum = docsEnum.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) {
            // get the term frequency in the document 
            System.out.println(term.utf8ToString()+ " " + docIdEnum + " " + docsEnum.freq()); 
        }
    }
}

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