Lucene5(1)简单示例

向右看齐 2022-06-07 00:53 103阅读 0赞

### NO BIBI亮代码 ###

private IndexWriter writer;
    private IndexReader reader;
    // lucene索引存放了路径
    private static final String INDEX_DIR = "E:/LuceneIndex";
    /** * 实例化写索引 */
    public IndexWriter getIndexWriter(String indexDir) throws Exception {
        if (writer == null) {
            Analyzer analyzer = getAnalyzer();
            IndexWriterConfig writerConfig = new IndexWriterConfig(analyzer);
            // Directory ramDirectory= new RAMDirectory();//索引写入内存
            // 索引存储磁盘位置
            Directory directory = FSDirectory.open(Paths.get(indexDir));
            writer = new IndexWriter(directory, writerConfig);
        }
        return writer;
    }
    
    /** * 获取读索引实体，并打印读到的索引信息 */
    public IndexReader getIndexReader(String indexDir) throws IOException {
        if (reader == null) {
            Directory directory = FSDirectory.open(Paths.get(indexDir));
            reader = DirectoryReader.open(directory);
            // 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("当前存储的文档数，包含回收站的文档:" + reader.maxDoc());
            System.out.println("回收站的文档数:" + reader.numDeletedDocs());
        }
        return reader;
    }
    
    /** * 关闭写索引 */
    public void close() throws Exception {
        writer.close();
        reader.close();
    }
    
    /** * 获取分词器 */
    private Analyzer getAnalyzer(){
        return new StandardAnalyzer();
    }
    
    @Test
    public void testWriter() throws Exception {
        IndexWriter writer = getIndexWriter(INDEX_DIR);
        Document document = new Document();// 实例化一个文档
        // 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();
    }
    
    @Test
    public void testReader() throws Exception {
        IndexReader reader = getIndexReader(INDEX_DIR);
        IndexSearcher searcher = new IndexSearcher(reader);
        // 指定Document被搜索的属性
        QueryParser parser = new QueryParser("describes", getAnalyzer());
        // 指定索引内容
        Query query = parser.parse("试");
        // 搜索前十个
        TopDocs hits = searcher.search(query, 10);
        for (ScoreDoc sd : hits.scoreDocs) {
            Document doc = searcher.doc(sd.doc);
            System.out.println(doc.get("name") + "[describes]=" + doc.get("describes"));
        }
        reader.close();
    }