Lucene：termFreqVector始终为空？

Question

对于任何文档，术语FreqVector始终为空。 我确定这些文档在集合和字段中存在。那么问题在哪里？

对（INT I = 0;我< reader.numDocs（）;我++）{
TermFreqVector TFV = reader.getTermFreqVector（I， “标签”）;

感谢

Answer 1

你确定你与你Field.TermVector.YES索引的字段？这里有一个工作示例：

Directory directory = new RAMDirectory(); 
Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_30); 
MaxFieldLength mlf = MaxFieldLength.UNLIMITED; 
IndexWriter writer = new IndexWriter(directory, analyzer, true, mlf); 

Document doc = new Document(); 
doc.add(new Field("tags", "foo bar", Field.Store.NO, 
     Field.Index.ANALYZED, Field.TermVector.YES)); 

writer.addDocument(doc); 
writer.close(); 

IndexReader reader = IndexReader.open(directory); 
for (int i = 0; i < reader.numDocs(); i++) { 
    TermFreqVector tfv = reader.getTermFreqVector(i, "tags"); 
    System.out.println(tfv); 
}