Lucene全文检索引擎

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

<modelVersion>4.0.0</modelVersion>

  <groupId>demo.lucene</groupId>

  <artifactId>Lucene01</artifactId>

  <version>0.0.1-SNAPSHOT</version>

  <build/>

  <dependencies>

    <!-- lucene核心包 -->

    <dependency>

        <groupId>org.apache.lucene</groupId>

        <artifactId>lucene-core</artifactId>

        <version>5.3.1</version>

    </dependency>

    <!-- lucene查询解析包 -->

    <dependency>

        <groupId>org.apache.lucene</groupId>

        <artifactId>lucene-queryparser</artifactId>

        <version>5.3.1</version>

    </dependency>

    <!-- lucene解析器包 -->

    <dependency>

        <groupId>org.apache.lucene</groupId>

        <artifactId>lucene-analyzers-common</artifactId>

        <version>5.3.1</version>

    </dependency>

  </dependencies>

</project>

import java.io.File;

import java.io.FileReader;

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.store.Directory;

import org.apache.lucene.store.FSDirectory;

/**

 * 建立索引的类

 * @author Ni Shengwu

 *

 */

public class Indexer {

    private IndexWriter writer; //写索引实例

    //构造方法，实例化IndexWriter

    public Indexer(String indexDir) throws Exception {

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

        Analyzer analyzer = new StandardAnalyzer(); //标准分词器，会自动去掉空格啊，is a the等单词

        IndexWriterConfig config = new IndexWriterConfig(analyzer); //将标准分词器配到写索引的配置中

        writer = new IndexWriter(dir, config); //实例化写索引对象

    }

    //关闭写索引

    public void close() throws Exception {

        writer.close();

    }

    //索引指定目录下的所有文件

    public int indexAll(String dataDir) throws Exception {

        File[] files = new File(dataDir).listFiles(); //获取该路径下的所有文件

        for(File file : files) {

            indexFile(file); //调用下面的indexFile方法，对每个文件进行索引

        }

        return writer.numDocs(); //返回索引的文件数

    }

    //索引指定的文件

    private void indexFile(File file) throws Exception {

        System.out.println("索引文件的路径：" + file.getCanonicalPath());

        Document doc = getDocument(file); //获取该文件的document

        writer.addDocument(doc); //调用下面的getDocument方法，将doc添加到索引中

    }

    //获取文档，文档里再设置每个字段，就类似于数据库中的一行记录

    private Document getDocument(File file) throws Exception{

        Document doc = new Document();

        //添加字段

        doc.add(new TextField("contents", new FileReader(file))); //添加内容

        doc.add(new TextField("fileName", file.getName(), Field.Store.YES)); //添加文件名，并把这个字段存到索引文件里

        doc.add(new TextField("fullPath", file.getCanonicalPath(), Field.Store.YES)); //添加文件路径

        return doc;

    }

    public static void main(String[] args) {

        String indexDir = "D:\\lucene"; //将索引保存到的路径

        String dataDir = "D:\\lucene\\data"; //需要索引的文件数据存放的目录

        Indexer indexer = null;

        int indexedNum = 0;

        long startTime = System.currentTimeMillis(); //记录索引开始时间

        try {

            indexer = new Indexer(indexDir);

            indexedNum = indexer.indexAll(dataDir);

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            try {

                indexer.close();

            } catch (Exception e) {

                e.printStackTrace();

            }

        }

        long endTime = System.currentTimeMillis(); //记录索引结束时间

        System.out.println("索引耗时" + (endTime-startTime) + "毫秒");

        System.out.println("共索引了" + indexedNum + "个文件");

    }

}

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.index.DirectoryReader;

import org.apache.lucene.index.IndexReader;

import org.apache.lucene.queryparser.classic.QueryParser;

import org.apache.lucene.search.IndexSearcher;

import org.apache.lucene.search.Query;

import org.apache.lucene.search.ScoreDoc;

import org.apache.lucene.search.TopDocs;

import org.apache.lucene.store.Directory;

import org.apache.lucene.store.FSDirectory;

public class Searcher {

	public static void search(String indexDir, String q) throws Exception {

        Directory dir = FSDirectory.open(Paths.get(indexDir)); //获取要查询的路径，也就是索引所在的位置

        IndexReader reader = DirectoryReader.open(dir);

        IndexSearcher searcher = new IndexSearcher(reader);

        Analyzer analyzer = new StandardAnalyzer(); //标准分词器，会自动去掉空格啊，is a the等单词

        QueryParser parser = new QueryParser("contents", analyzer); //查询解析器

        Query query = parser.parse(q); //通过解析要查询的String，获取查询对象

        long startTime = System.currentTimeMillis(); //记录索引开始时间

        TopDocs docs = searcher.search(query, 10);//开始查询，查询前10条数据，将记录保存在docs中

        long endTime = System.currentTimeMillis(); //记录索引结束时间

        System.out.println("匹配" + q + "共耗时" + (endTime-startTime) + "毫秒");

        System.out.println("查询到" + docs.totalHits + "条记录");

        for(ScoreDoc scoreDoc : docs.scoreDocs) { //取出每条查询结果

            Document doc = searcher.doc(scoreDoc.doc); //scoreDoc.doc相当于docID,根据这个docID来获取文档

            System.out.println(doc.get("fullPath")); //fullPath是刚刚建立索引的时候我们定义的一个字段

        }

        reader.close();

    }

    public static void main(String[] args) {

        String indexDir = "D:\\lucene";

        String q = "generate-maven-artifacts"; //查询这个字符串

        try {

            search(indexDir, q);

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

}

pom.xml

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