lucene5(2)索引增删改查

1、增加索引

@Test
public void TestInsert() throws Exception {
    IndexWriter writer = getIndexWriter(indexDir);
    Document document = new Document();
    // 添加一个文档信息，相当于一个数据库表字段
    document.add(new TextField("name", "hello world", Field.Store.YES));
    document.add(new TextField("describes", "测试luence", Field.Store.YES));
    writer.addDocument(document);
    writer.close();
}

2、更新索引

@Test
public void TestUpdate() throws Exception {
    // Lucene并没有提供更新，这里的更新操作相当于新增，他并不会去掉原来的信息
    IndexWriter writer = getIndexWriter(indexDir);
    Document doc = new Document();
    doc.add(new StringField("name", "ckl", Field.Store.YES));
    doc.add(new StringField("describes", "chenkailing", Field.Store.YES));
    writer.updateDocument(new Term("name", "hello world"), doc);
    //需要将原来的索引删除
    // TODO
    writer.close();
}

3、删除索引

@Test
public void TestDelete() throws Exception {
    IndexWriter writer = getIndexWriter(indexDir);
    QueryParser parser = new QueryParser("name", getAnalyzer());
    Query query = parser.parse("ckl");
    // 此时删除的文档并不会被完全删除，而是存储在一个回收站中的，可以恢复
    writer.deleteDocuments(query);
    // 强制合并删除的索引信息，索引量大的时候不推荐使用，真正的删除
    writer.forceMergeDeletes();
    //更改索引要提交，和提交数据库事务一个概念，真正的删除
    writer.commit();
    writer.close();
}

4、查询索引

@Test
public void TestSearch() throws Exception {
    IndexReader reader = getIndexReader();
    IndexSearcher searcher = new IndexSearcher(reader);
    // 指定Document的某个属性
    QueryParser parser = new QueryParser("name", getAnalyzer());
    // 指定索引内容，对应某个分词
    Query query = parser.parse("ckl");
    TopDocs hits = searcher.search(query, 10);
    for (ScoreDoc sd : hits.scoreDocs) {
        Document doc = searcher.doc(sd.doc);
        System.out.println("name:" + doc.get("name") + ",describes:" + doc.get("describes"));
    }
    reader.close();
}

5、读取索引信息

public static IndexReader getIndexReader() throws Exception {
    IndexReader reader = null;
    reader = DirectoryReader.open(getDirectory(indexDir));
    // 通过reader可以有效的获取到文档的数量
    System.out.println("当前存储的文档数:" + reader.numDocs());
    System.out.println("回收站的文档数:" + reader.numDeletedDocs());
    System.out.println("当前存储的文档数，包含回收站的文档:" + reader.maxDoc());
    return reader;
}