Why I can't get the doc that added recently by IndexWriter in the search result in Lucene 4.0? - lucene

Question

Such as the title said, I have encountered a puzzled problem.
I have built an index for my test program, then I use IndexWriter to add a document into index. The code is :
IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_CURRENT, analyzer);
IndexWriter iwriter = new IndexWriter(directory, config);
Document doc1 = new Document();
doc1.add(new Field("name", "张三", Field.Store.YES, Field.Index.ANALYZED));
doc1.add(new IntField("year", 2013, Field.Store.YES));
doc1.add(new TextField("content", "123456789", Field.Store.YES));
iwriter.addDocument(doc1);
iwriter.commit();
iwriter.close();
When I try to search in this index, I can't get this doc. I really get a correct result count, it is one more than before. But when I try to print the doc.get('name'), the output is wrong.
The code in search part is:
DirectoryReader ireader = DirectoryReader.open(directory);
System.out.println(ireader.numDeletedDocs());
IndexSearcher isearcher = new IndexSearcher(ireader);
// Parse a simple query that searches for "text":
QueryParser parser = new QueryParser(Version.LUCENE_CURRENT, "name", analyzer);
Query query = parser.parse("张");
ScoreDoc[] hits = isearcher.search(query, null, 1000).scoreDocs;
System.out.println(hits.length);
In results, there is a "Name: 李四".
I'm sure that I use the StandardAnalyzer during indexing and searching. And StandardAnalyzer will make one Chinese character as a single token. Why when I search "张", I will get "李四"? Is there anything wrong when I add a doc? Or the docid is mismatch?

Answer 1

Did you (re)open the index after adding the doc? Lucene searches only return the documents that existed as of the time the index was opened for searching.
[edit...]
Use IndexReader.Open() or IndexReader.doOpenIfChanged() to open the index again. doOpenIfChanged() has the advantage that it returns null if you can still use the old IndexReader instance (because the index has not changed).
(If I recall correctly, DirectoryReader.Open() just opens the index directory, so the higher-level Lucene code does not realize that the index has changed if you just call DirectoryReader.Open.)