全文检索的Demo

用到lucene版本为6.3.0版本,利用的分词器为IKAnalyzer分词器,该分词对中文有较好的支持。关于支持lucene的6.xx以上的IkAnalyzer分词jar包下载地址:https://pan.baidu.com/s/1i5DreTZ

密码:2frx 

package com.cn.shupu.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.file.Paths;

import javax.management.Query;

import org.apache.ibatis.javassist.bytecode.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.cn.smart.SmartChineseAnalyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Store;
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.index.IndexableField;
import org.apache.lucene.index.IndexableFieldType;
import org.apache.lucene.index.LogByteSizeMergePolicy;
import org.apache.lucene.index.LogMergePolicy;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import org.apache.lucene.queryparser.classic.MultiFieldQueryParser;
import org.apache.lucene.queryparser.classic.ParseException;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.BooleanClause.Occur;
import org.apache.lucene.search.highlight.Fragmenter;
import org.apache.lucene.search.highlight.Highlighter;
import org.apache.lucene.search.highlight.InvalidTokenOffsetsException;
import org.apache.lucene.search.highlight.QueryScorer;
import org.apache.lucene.search.highlight.SimpleFragmenter;
import org.apache.lucene.search.highlight.SimpleHTMLFormatter;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.BytesRef;
import org.apache.xmlbeans.impl.store.Path;
import org.wltea.analyzer.lucene.IKAnalyzer;

public class LuceneUtils {

    // 索引文件的存放路径
    private static String indexPath = "D://index/path";

    // 要索引的文件(假如要索引的文件类型为txt文件)
    private static String tarPath = "D://font//管理学(第四版).txt";

    // 创建索引的方法
    public static void createIndex() {

        File filDir = new File(tarPath);

        File idnexDir = new File(indexPath);

        Boolean create = true;

        if (!idnexDir.exists()) {
            idnexDir.mkdirs();
        }

        // 创建文件索引
        try {
            Directory directroy = FSDirectory.open(Paths.get(indexPath));
            // 创建内存索引
            RAMDirectory ramDirectory = new RAMDirectory();

            // 创建分词器
            // 1.创建 SmartChineseAnalyze分词器
            // SmartChineseAnalyzer analyzer=new SmartChineseAnalyzer();
            // 2.创建StantdarAnalyzer
            // StandardAnalyzer analyzer = new StandardAnalyzer();

            // 3.创建IKAnalyzer
            IKAnalyzer analyzer = new IKAnalyzer();

            // 尚未初始化,因为第一次执行分词的时候才会初始化,为了在执行分此前手动添加额外的字典,需要先手动的初始化一下
            /*
             * Configuration cfg = DefaultConfig.getInstance(); // 加载词库
             * cfg.setUseSmart(true); // 设置智能分词
             * org.wltea.analyzer.dic.Dictionary.initial(cfg);
             * 
             * org.wltea.analyzer.dic.Dictionary dictionary =
             * org.wltea.analyzer.dic.Dictionary.getSingleton();
             * 
             * List<String> newWords = new ArrayList<>();
             * 
             * for (BaseLib book : books) {
             * 
             * newWords.add(book.getName());
             * 
             * } dictionary.addWords(newWords);// 自动添加自定义分词
             */
            // 创建索引器之前的初始化
            IndexWriterConfig iwc = new IndexWriterConfig(analyzer);
            IndexWriterConfig rwc = new IndexWriterConfig(analyzer);

            // SetMergeFactor是控制segment合并频率的,其决定了一个索引块中包括多少个文档,当硬盘上的索引块达到多少时,
            // 将它们合并成一个较大的索引块。当MergeFactor值较大时,生成索引的速度较快。MergeFactor的默认值是10,建议在建立索引前将其设置的大一些。
            LogMergePolicy mergePolicy = new LogByteSizeMergePolicy();
            mergePolicy.setMergeFactor(100);
            iwc.setMergePolicy(mergePolicy);
            iwc.setRAMBufferSizeMB(2048);
            iwc.setMaxBufferedDocs(1000);
            iwc.setMaxBufferedDocs(1000);

            if (create) {
                // Create a new index in the directory, removing any
                // previously indexed documents:
                // 在目录中创建一个新的索引,删除任何先前生成的索引文档
                rwc.setOpenMode(OpenMode.CREATE);

            } else {
                // Add new documents to an existing index:
                // 新文档添加到一个现有的指数
                rwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
            }

            // 文件索引生成器
            IndexWriter fileWriter = new IndexWriter(directroy, iwc);

            // 内存索引生成器
            IndexWriter ramWriter = new IndexWriter(ramDirectory, rwc);

            // 现将索引添加到内存索引中

            // 创建文档
            Document document = new Document();

            // 添加term,term为索引文件中最小的单位,就像数据库中每一表的field。

            // 获取文件的内容
            String content = getTxt(filDir);

            // 其中Store.YESb表示索引的内容要保存的,Store.NO表示索引内容只索引不保存

            document.add(new TextField("path", filDir.getAbsolutePath(), Store.YES));

            document.add(new TextField("content", content, Store.YES));

            // 根据文件的初始的OpenMode来对文件索引的添加或修改
            if (ramWriter.getConfig().getOpenMode() == OpenMode.CREATE) {

                System.out.println("adding " + filDir.getAbsolutePath());

                ramWriter.addDocument(document);

            } else {

                System.out.println("updating " + filDir.getAbsolutePath());
                ramWriter.updateDocument(new Term("path", filDir.toString()), document);
            }

            ramWriter.close();

            // 将内存索引添加文件索引中,永久保存。内存索引只是暂时的保存索引文件,当程序结束时,内存索引的文件会消失
            fileWriter.addIndexes(new Directory[] { ramDirectory });
            fileWriter.forceMerge(1000);
            fileWriter.maybeMerge();
            fileWriter.close();

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    /**
     * 121 * 读取txt文件的内容 122 * @param file 想要读取的文件对象 123 * @return 返回文件内容 124
     */
    public static String getTxt(File file) {
        String result = "";
        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file), "GBK"));
            String s = null;
            while ((s = br.readLine()) != null) {// 使用readLine方法,一次读一行

                result = result + "
" + s;

            }
            br.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    public static void searchByKeyWord(String keyWord) {

        try {
            Directory directory = FSDirectory.open(Paths.get(indexPath));

            // 采用IkAnalyzer,其中true为智能分词。
            IKAnalyzer analuzer = new IKAnalyzer(true);

            // 创建索引的读器
            IndexReader ireader = DirectoryReader.open(directory);
            // 创建索引的搜索器
            IndexSearcher isearcher = new IndexSearcher(ireader);

            String[] stringQuery = { keyWord, keyWord };// 查询关键词的数组

            String[] fields = { "path", "content" };// 多字段查询的值域

            // Occur.MUST表示对应字段必须有查询值, Occur.MUST_NOT
            // 表示对应字段必须没有查询值,Occur.SHOULD表示对应字段应该存在查询值(但不是必须)
            Occur[] occ = { Occur.SHOULD, Occur.SHOULD };

            org.apache.lucene.search.Query query = null;
            try {
                query = MultiFieldQueryParser.parse(stringQuery, fields, occ, analuzer);
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            /*
             * // 只对content进行检索 QueryParser parser = new QueryParser("contents",
             * analyzer);
             * 
             * Query query = parser.parse(text);
             */

            // 排序
            SortField sf = new SortField(keyWord, SortField.Type.STRING_VAL, true);

            Sort sort = new Sort(sf);

            int count;

            // 获取一共多少条数据
            TopDocs docs = null;
            ScoreDoc[] hits = null;
            docs = isearcher.search(query, Integer.MAX_VALUE, sort);
            hits = docs.scoreDocs;
            // 假如用到分页的时候,用 docs =
            // isearcher.searchAfter(results.scoreDocs[page.getAfterDocId()],
            // query, page.getPagesize(), sort);

            for (int i = 0; i < hits.length; i++) {
                Document doc = isearcher.doc(hits[i].doc);

                System.out.println("文件路径:" + doc.get("path"));

                String content = doc.get("content");
                // 查询字段高亮操作 其中100为字符长度可以自动修改的;
                String s = null;
                try {
                    s = displayHtmlHighlight(query, analuzer, "content", content, 290);
                } catch (InvalidTokenOffsetsException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                System.out.println("内容:" + s);

            }

            ireader.close();
            directory.close();

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    /**
     * 获取高亮显示结果的html代码
     * 
     * @param query
     *            查询
     * @param analyzer
     *            分词器
     * @param fieldName
     *            域名
     * @param fieldContent
     *            域内容
     * @param fragmentSize
     *            结果的长度(不含html标签长度)
     * @return 结果(一段html代码)
     * @throws IOException
     * @throws InvalidTokenOffsetsException
     */
    static String displayHtmlHighlight(org.apache.lucene.search.Query query,
            org.apache.lucene.analysis.Analyzer analyzer, String fieldName, String fieldContent, int fragmentSize)
            throws IOException, InvalidTokenOffsetsException {
        // 创建一个高亮器
        Highlighter highlighter = new Highlighter(new SimpleHTMLFormatter("<font color='red'>", "</font>"),
                new QueryScorer(query));
        Fragmenter fragmenter = new SimpleFragmenter(fragmentSize);
        highlighter.setTextFragmenter(fragmenter);
        return highlighter.getBestFragment(analyzer, fieldName, fieldContent);
    }

    public static void main(String[] args) {
        //本Demo只对txt文件类型做的索引
        createIndex();
        searchByKeyWord("管理");
        
    }

}
原文地址:https://www.cnblogs.com/git-niu/p/7112310.html