Lucene

轉自 http://mybar.iteye.com/blog/1933351

今天看了下Lucene的更新，已經到4.4.0的版本了，並且新的API變化也比較多，對於老版本的Lucene想要升級到最新的版本，不是簡單的更新jar包就能夠的。

    下面寫了個簡單的小例子。能夠看一下

 

1.建立maven工程

    在eclipse裏面建立個maven項目，一個簡單的項目便可，下面是對於的pom.xml文件，須要將Lucene的jar包引入進來。

<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>com.jacksoft</groupId>
  <artifactId>Lucene-test</artifactId>
  <version>0.0.1-SNAPSHOT</version>

  <properties>
    <lucene.version>4.4.0</lucene.version>
  </properties>

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

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

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



  </dependencies>

</project>

   這裏只是簡單的添加依賴關係，下載好jar包以後，我在本地建立了3個txt文件，以下：

  

  

 準備工做就差很少了，下面就開始進行編碼工做

 

2. 編碼

    因爲是多個文件的搜索，這裏建立一個工具類來遞歸目錄，找到這三個txt文件，我將這三個txt文件放在本地:D:\lucene\luceneData目錄中

   

package com.jacksoft.lucene.util;

import java.io.File;
import java.util.List;

public class FileUtils {

    public static void listFile(File f,List<String> fileList){
        if(f.isDirectory()){
            File[] files = f.listFiles();
            for(int i=0;i<files.length ;i++)
            {
                listFile(files[i],fileList) ;
            }
        }else{
            fileList.add(f.getAbsolutePath());
        }
    }
}

    這樣返回的fileList中就包含了咱們須要的txt文件，固然這裏還能夠設置過濾器來指定後綴名。

  接下來就是建立索引和查詢的過程：

 

package com.jacksoft.lucene;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.TextField;
import org.apache.lucene.document.Field.Store;
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.index.IndexWriterConfig.OpenMode;
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;
import org.apache.lucene.util.Version;

import com.jacksoft.lucene.util.FileUtils;

/**
 *  多文件搜索
 * @Project Lucene-test
 *
 * @Filename MultLuceneTest2.java
 *
 * @author Jack.Zhou
 *
 * @Date 2013-8-29
 *
 */
public class LuceneTest {

    private static final String QUERY_STR = "四川";

    private static final String FILE_TARGET = "D:\\lucene\\luceneData";

    private static final String FILE_INDEX = "D:\\lucene\\luceneIndex";


    public static void main(String[] args) {
        try {
            LuceneTest t = new LuceneTest();
            t.createIndex();
            t.searchByKeyWords(QUERY_STR);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     *  建立索引
     * @throws Exception
     */
    private void createIndex() throws Exception{
        Long startTime = System.currentTimeMillis();
        File indexDir = new File(FILE_INDEX);
        Analyzer luceneAnalyzer = new StandardAnalyzer(Version.LUCENE_44);
        IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_44, luceneAnalyzer);
        config.setOpenMode(OpenMode.CREATE);
        Directory directory = FSDirectory.open(indexDir);
        IndexWriter indexWriter = new IndexWriter(directory, config);
        List<String> fileList = new ArrayList<String>();
        FileUtils.listFile(new File(FILE_TARGET), fileList);
        for(String filePath : fileList){
            System.out.println("文件:" + filePath + "正在被索引....");
            String content = readFile(filePath);
            Document doc = new Document();
            doc.add(new TextField("content", content.toString(), Store.YES));
            doc.add(new TextField("path", filePath, Store.YES));
            indexWriter.addDocument(doc);
        }
        indexWriter.close();
        Long endTime = System.currentTimeMillis();
        System.out.println("花費了" + (endTime - startTime) + "毫秒來建立索引文件");

    }
    /**
     *  讀取文件內容
     * @param filePath
     * @return
     * @throws Exception
     */
    private String readFile(String filePath) throws Exception{
        @SuppressWarnings("resource")
        BufferedReader bufferedReader = new BufferedReader(
                new InputStreamReader(new FileInputStream(filePath)));
        StringBuffer content = new StringBuffer();
        String str = null;
        while ((str = bufferedReader.readLine()) != null) {
            content.append(str).append("\n");
        }
        return content.toString();
    }


    private void searchByKeyWords(String keyWords) throws Exception{
        IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(FILE_INDEX)));
        IndexSearcher searcher = new IndexSearcher(reader);
        Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_44);
        QueryParser parser = new QueryParser(Version.LUCENE_44, "content",analyzer);
        Query query = parser.parse(keyWords);
        TopDocs results = searcher.search(query,1000);
        ScoreDoc[] score = results.scoreDocs;
        if (score.length == 0) {
            System.out.println("對不起，沒有找到您要的結果。");
        } else {
            System.out.println("查找["+QUERY_STR+"]有" + score.length + "個結果");
            for (int i = 0; i < score.length; i++) {
                try {
                    Document doc = searcher.doc(score[i].doc);
                    System.out.print("這是第" + i + "個檢索到的結果，文件名爲：");
                    System.out.println(doc.get("path"));
                    System.out.println("內容:\n" + doc.get("content"));
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

 

   代碼中的常量能夠經過文檔來查看，運行後就能夠看到搜索的結果了。

 

   固然這裏只是對txt進行搜索，你還能夠對word，excel，pdf等文檔進行搜索，前提是要將其內容讀取出來，建立索引便可。