Lucene是一个全文检索的框架，apache组织提供了一个用Java实现的全文搜索引擎的开源项目。这里我们对apache的lucene的框架做一个简单的介绍。心甘情愿这四个字，透着一股卑微，但也有藏不住的勇敢。

lucene的第一个实例

一、maven中引入的依赖pom.xml

<properties>
    <lucene.version>6.6.0</lucene.version>
    <common-io.version>2.5</common-io.version>
</properties>

<dependencies>
    <!-- lucene core的依赖-->
    <dependency>
        <groupId>org.apache.lucene</groupId>
        <artifactId>lucene-core</artifactId>
        <version>${lucene.version}</version>
    </dependency>

    <dependency>
        <groupId>org.apache.lucene</groupId>
        <artifactId>lucene-queryparser</artifactId>
        <version>${lucene.version}</version>
    </dependency>

    <!-- commomsIO的依赖-->
    <dependency>
        <groupId>commons-io</groupId>
        <artifactId>commons-io</artifactId>
        <version>${common-io.version}</version>
    </dependency>
</dependencies>

二、关于lucene的java代码如下

package com.linux.huhx.lucene_1;

import org.apache.commons.io.FileUtils;
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.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
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.RAMDirectory;

import java.io.File;
import java.io.IOException;

public class BaseLucene_1 {
    public static void main(String[] args) throws Exception {
        // 存放在内存中
        Directory dir = new RAMDirectory();
        new BaseLucene_1().createIndex(dir);
        new BaseLucene_1().search(dir);
    }

    /**
     * 创建索引
     */
    public void createIndex(Directory dir) throws IOException {
        IndexWriter indexWriter = null;
        // 1. 创建 Directory (索引存放位置)，这里是参数dir

        // 2. 创建IndexWriter 写索引
        Analyzer analyzer = new StandardAnalyzer();
        IndexWriterConfig iwc = new IndexWriterConfig(analyzer);
        indexWriter = new IndexWriter(dir, iwc);

        // 3. 创建Document 对象 field
        Document document;
        File file = new File("file/example");
        for (File f : file.listFiles()) {
            document = new Document();

            // 4. 为Documen添加field
            document.add(new Field("content", FileUtils.readFileToString(f, "utf-8"), TextField.TYPE_STORED));
            document.add(new TextField("fileName", f.getName(), Field.Store.YES));
            document.add(new StringField("filePath", f.getAbsolutePath(), Field.Store.YES));
            // 5. 通过IndexWriter 添加文档到索引中
            indexWriter.addDocument(document);
        }
        indexWriter.close();
    }

    /**
     * 根据内容搜索
     * @param dir
     * @throws Exception
     */
    public void search(Directory dir) throws Exception {
        IndexReader indexReader = null;
        // 1. 创建 Directory，这里通过参数传递过来的dir
        // Directory dir = FSDirectory.open(new File("file/index").toPath()); // 本地磁盘

        // 2. 创建 IndexReader
        indexReader = DirectoryReader.open(dir);

        // 3. 创建 IndexSearch
        IndexSearcher indexSearcher = new IndexSearcher(indexReader);

        // 4. 创建搜索的Query
        // 创建parse确定搜索的内容，第二个参数为搜索的file
        QueryParser queryParser = new QueryParser("content", new StandardAnalyzer());

        // 创建Query，表示搜索域中的内容
        Query query = queryParser.parse("love");

        // 5. 搜索并返回 TopDocs
        TopDocs topDocs = indexSearcher.search(query, 10);

        // 6. 根据topDocs 获得 scoreDocs
        ScoreDoc[] socreDocs = topDocs.scoreDocs;

        for (ScoreDoc doc : socreDocs) {
            // 获取Document对象
            Document document = indexSearcher.doc(doc.doc);

            // 根据Document对象获取需要的值
            System.out.println(document.get("fileName"));
            System.out.println(document.get("content"));
        }
        indexReader.close();
    }
}

三、运行的结果如下

java1.txt
I love you, java.
java2.txt
I love you, linux.
java3.txt
I love you, huhx.

友情链接