package com.shyroke.lucene;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

import java.nio.file.Paths;

import org.apache.lucene.analysis.Analyzer;

import org.apache.lucene.analysis.standard.StandardAnalyzer;

import org.apache.lucene.document.Document;

import org.apache.lucene.document.Field;

import org.apache.lucene.document.TextField;

import org.apache.lucene.index.IndexWriter;

import org.apache.lucene.index.IndexWriterConfig;

import org.apache.lucene.index.IndexableFieldType;

import org.apache.lucene.queries.function.valuesource.DualFloatFunction;

import org.apache.lucene.store.Directory;

import org.apache.lucene.store.SimpleFSDirectory;

public class Indexer {

    // 写索引

    private IndexWriter indexWriter;

    /**

     * 实例化写索引

     *

     * @param dir

     *            保存索引的目录

     * @throws IOException

     */

    public Indexer(String dir) throws IOException {

        Directory indexDir = new SimpleFSDirectory(Paths.get(dir));

        /**

         * IndexWriterConfig实例化该类的时候如果是空的构造方法，那么默认 public IndexWriterConfig() { this(new

         * StandardAnalyzer()); }

         */

        Analyzer analyzer=new StandardAnalyzer();  //分词器

        IndexWriterConfig conf = new IndexWriterConfig(analyzer);

        indexWriter = new IndexWriter(indexDir, conf);

    }

    /**

     * 索引文件

     */

    public void index(File file) throws Exception {

        System.out.println("被索引的文件为：" + file.getCanonicalPath());

        Document document = getDocument(file);

        indexWriter.addDocument(document);

    }

    /**

     * 从文件中获取文档

     *

     * @param file

     * @return

     * @throws IOException

     */

    private Document getDocument(File file) throws IOException {

        Document document = new Document();

        Field contentField = new TextField("fileContents", new FileReader(file));

        /**

         * Field.Store.YES表示把该Field的值存放到索引文件中，提高效率，一般用于文件的标题和路径等常用且小内容小的。

         */

        Field fileNameField = new TextField("fileName", file.getName(), Field.Store.YES);

        Field filePathField = new TextField("filePath", file.getCanonicalPath(), Field.Store.YES);

        document.add(contentField);

        document.add(fileNameField);

        document.add(filePathField);

        return document;

    }

    /**

     * 创建索引

     *

     * @param dataFile 数据文件所在的目录

     * @return 索引文件的数量

     * @throws Exception

     */

    public int CreateIndex(String dataFile, FileFilter filter) throws Exception {

        File[] files = new File(dataFile).listFiles();

        for (File file : files) {

            /**

             * 被索引文件必须不能是 1.目录 2.隐藏  3. 不可读 4.不是txt文件，

             * 否则不被索引

             */

            if (!file.isDirectory() && !file.isHidden() && file.canRead() && filter.accept(file)) {

                index(file);

            }

        }

        return indexWriter.numDocs();

    }

    /**

     * 关闭写索引

     *

     * @throws IOException

     */

    public void close() throws IOException {

        indexWriter.close();

    }

}

public class SearchTest {

    private IndexWriter writer;

    private IndexSearcher search;

    private IndexReader reader;

    private String indexDir = "E:\\\\lucene4\\\\index";

    private String dataDir = "E:\\\\lucene4\\\\data";

    @Before

    public void setUp() throws Exception {

        Indexer indexer = new Indexer(indexDir);

        indexer.CreateIndex(dataDir, new FileFilter());

        /**

         * 一定要把IndexWriter实例关闭，否则segments_1文件不会生成。

         */

        indexer.close();

        Directory indexDirectory = FSDirectory.open(Paths.get(indexDir));

         reader = DirectoryReader.open(indexDirectory);

        search = new IndexSearcher(reader);

    }

    @After

    public void tearDown() throws Exception {

        reader.close();

    }

    /**

     * 对特定项搜索

     * @throws IOException

     */

    @Test

    public void textTermQuery() throws IOException {

        System.out.println("--------------------");

        String key = "particular";

        Term t = new Term("fileContents", key);

        Query query = new TermQuery(t);

        TopDocs hits = search.search(query, 10);

        System.out.println("匹配 '" + key + "'，总共查询到" + hits.totalHits + "个文档");

        for (ScoreDoc scoreDoc : hits.scoreDocs) {

            Document doc = search.doc(scoreDoc.doc);

            System.out.println(doc.get("filePath"));

        }

    }

}

/**

     * 解析查询表达式,在要搜索的关键字中可以使用AND OR ~ * ?等

     * AND 与      OR 或   ~相近

     * AND和OR只能大写

     * @throws ParseException

     * @throws IOException

     */

    @Test

    public void testQueryParse() throws ParseException, IOException {

        System.out.println("--------------------");

        Analyzer analyzer=new StandardAnalyzer();

        QueryParser parser=new QueryParser("fileContents", analyzer);

        String key="Source* AND Derivati*";

        Query query=parser.parse(key);

        TopDocs hits =search.search(query, 10);

        System.out.println("匹配 '" + key + "'，总共查询到" + hits.totalHits + "个文档");

        for (ScoreDoc scoreDoc : hits.scoreDocs) {

            Document doc = search.doc(scoreDoc.doc);

            System.out.println(doc.get("filePath"));

        }

    }