lucene

時間 2019-11-30

標籤 lucene 简体版

原文原文鏈接

1 全文檢索工具，方便實現全文檢索功能。服務器

2 全文檢索，先對要搜索的文檔進行分詞，造成索引，根據索引經行檢索。ide

3 全文檢索流程工具

索引流程：採集數據，處理數據，建立索引post

搜索流程：輸入查詢條件，Lucene查詢器查詢索引，索引庫取出結果spa

4 IndexWriter是索引過程的核心組件，經過IndexWriter能夠建立新索引、更新索引、刪除索引操做。IndexWriter須要經過Directory對索引進行存儲操做。code

Directory描述了索引的存儲位置，底層封裝了I/O操做，負責對索引進行存儲。它是一個抽象類，它的子類經常使用的包括FSDirectory（在文件系統存儲索引）、RAMDirectory（在內存存儲索引）。xml

public class IndexManager {

    @Test
    public void createIndex() throws Exception {
        BookDao bookDao = new BookDaoImpl();
        List<Book> books = bookDao.queryBooks();
        List<Document> documents = new ArrayList<>();
        
        Document document = null;
        for (Book book : books) {
            document = new Document();
            Field id = new TextField("id", book.getId().toString(), Store.YES);
            Field name = new TextField("name", book.getName(), Store.YES);
            Field price = new TextField("price", book.getPrice().toString(), Store.YES);
            Field detail = new TextField("detail", book.getDetail(), Store.YES);
            document.add(id);
            document.add(name);
            document.add(price);
            document.add(detail);
            documents.add(document);
        }
        
        Analyzer analyzer = new StandardAnalyzer();
        IndexWriter indexWriter = null;
        IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_4_10_3, analyzer);
        Directory directory = FSDirectory.open(new File("E:\\index\\"));
        indexWriter = new IndexWriter(directory, config);
        
        for (Document d : documents) {
            indexWriter.addDocument(d);
        }
        indexWriter.close();
    }
}

View Code

5 搜索輸入語法 and or not 大寫blog

    public void indexSearch() throws Exception {
        QueryParser queryParser = new QueryParser("detail", new StandardAnalyzer());
        Query query = queryParser.parse("detail:好 AND 大");
        Directory directory = FSDirectory.open(new File("E:\\index\\"));
        IndexReader indexReader = DirectoryReader.open(directory);
        IndexSearcher searcher = new IndexSearcher(indexReader);
        TopDocs docs = searcher.search(query, 10);
        ScoreDoc[] scoreDocs = docs.scoreDocs;
        for (ScoreDoc scoreDoc : scoreDocs) {
            int docId = scoreDoc.doc;
            Document document = searcher.doc(docId);
            System.out.println(document.get("id"));
            System.out.println(document.get("name"));
            System.out.println(document.get("detail"));
        }
        indexReader.close();
    }

View Code

5 field 屬性排序

1 是否分詞 tokenized 分詞爲了索引，（商品名稱，描述，價格），不分詞也能夠索引（商品id）索引

2 是否索引ndexed

3 是否存儲 stored 是否將field存到文檔域中，存儲目的顯示。名稱，價格，id，圖片地址

@Test
    public void createIndex() throws Exception {
        BookDao bookDao = new BookDaoImpl();
        List<Book> books = bookDao.queryBooks();
        List<Document> documents = new ArrayList<>();
        
        Document document = null;
        for (Book book : books) {
            document = new Document();
            Field id = new StringField("id", book.getId().toString(), Store.YES);
            Field name = new TextField("name", book.getName(), Store.YES);
            Field price = new FloatField("price", book.getPrice(), Store.YES);
            Field detail = new TextField("detail", book.getDetail(), Store.NO);
            document.add(id);
            document.add(name);
            document.add(price);
            document.add(detail);
            documents.add(document);
        }
        
        Analyzer analyzer = new StandardAnalyzer();
        IndexWriter indexWriter = null;
        IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_4_10_3, analyzer);
        Directory directory = FSDirectory.open(new File("E:\\index\\"));
        indexWriter = new IndexWriter(directory, config);
        
        for (Document d : documents) {
            indexWriter.addDocument(d);
        }
        indexWriter.close();
    }
}

View Code

6 修改索引

    @Test
    public void updateIndex() throws Exception {
        Analyzer analyzer = new StandardAnalyzer();
        IndexWriter indexWriter = null;
        IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_4_10_3, analyzer);
        Directory directory = FSDirectory.open(new File("E:\\index\\"));
        indexWriter = new IndexWriter(directory, config);
        Document document = new Document();
        document.add(new TextField("name", "fdrr", Store.YES));
        indexWriter.updateDocument(new Term("name", "fddd"), document);
        indexWriter.close();
    }