How can I retrieve the total number of documents indexed by Lucene in 3.0.2?

Question

我正在搜索一些文档，我想返回匹配的文档数量与索引的文档数量。

Answer 1

You could create a MatchAllDocsQuery which according to the javadocs states:

A query that matches all documents.

Otherwise perhaps the IndexReader might be useful:

IndexReader.open("path/to/index").numDocs();