Lucene初步学习

1.什么是Lunece

一个全文检索的框架

2.Lunce的索引搜索的原理

分为两部分创建索引和搜索索引

 倒排索引：通过一定的算法排序并且通过链表的结构连接如java->1->3这样的链表

通过倒排索引找到数据区

 3.简单使用

在Java中导入导包

<dependency>
            <groupId>org.apache.lucene</groupId>
            <artifactId>lucene-core</artifactId>
            <version>5.5.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.lucene</groupId>
            <artifactId>lucene-analyzers-common</artifactId>
            <version>5.5.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.lucene</groupId>
            <artifactId>lucene-queryparser</artifactId>
            <version>5.5.0</version>
        </dependency>

通过Java代码操作

 创建索引库

//1.准备存放的磁盘
        String index=new String("F:/IDEAWorkSpace/lucene_learn/src/index");
        //2.准备Docment文档
        Document document1 = new Document();
        //传入参数为name=type,第二个参数为文档 Field.Store.YES是否保存数据到数据区
        IndexableField indexableField=new TextField("context",doc1, Field.Store.YES);
        document1.add(indexableField);

        Document document2 = new Document();
        IndexableField indexableField1=new TextField("context",doc2, Field.Store.YES);
        document2.add(indexableField1);

        Document document3 = new Document();
        IndexableField indexableField2=new TextField("context",doc3, Field.Store.YES);
        document3.add(indexableField2);
        //准备路径
        Path path = Paths.get(index);
        Directory directory = FSDirectory.open(path);
        //准备分词器
        Analyzer analyzer = new SimpleAnalyzer();
        IndexWriterConfig conf = new IndexWriterConfig(analyzer);
        //3.准备IndexWriter（索引写入器）
        IndexWriter indexWriter = new IndexWriter(directory, conf);
        //读入文档
        indexWriter.addDocument(document1);
        indexWriter.addDocument(document2);
        indexWriter.addDocument(document3);
        //提交数据
        indexWriter.commit();
        //关闭indexWriter
        indexWriter.close();

查询索引库

 //1封装查询对象
        String keyWord="hello";
        //2准备IndexSearcher 类
        String index=new String("F:/IDEAWorkSpace/lucene_learn/src/index");
        Path path = Paths.get(index);
        Directory directory = FSDirectory.open(path);
        //获得DirectoryReader
        DirectoryReader open = DirectoryReader.open(directory);
        //获得IndexSearcher对象
        IndexSearcher indexSearcher = new IndexSearcher(open);
        //获得query对象
        TermQuery query = new TermQuery(new Term("context", "java"));
        //3使用IndexSearcher查询对象做查询-
        TopDocs search = indexSearcher.search(query, 1000);
        //获得查询分数及
        ScoreDoc[] scoreDocs = search.scoreDocs;
        for (ScoreDoc scoreDoc : scoreDocs) {
            //得到文档ID
            int id = scoreDoc.doc;
            //通过id获得文档
            Document doc = indexSearcher.doc(id);
            System.out.println(doc);
        }
        //封装对象