【Lucene】三个高亮显示模块的简单示例-Highlighter

Lucene针对高亮显示功能提供了两种实现方式,分别是Highlighter和FastVectorHighlighter

这里的三个示例都是使用Highlighter；

示例代码：

package com.tan.code;

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

import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.core.SimpleAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryparser.classic.ParseException;
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.TermQuery;
import org.apache.lucene.search.TopDocs;
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.SimpleHTMLFormatter;
import org.apache.lucene.search.highlight.SimpleSpanFragmenter;
import org.apache.lucene.search.highlight.TokenSources;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.SimpleFSDirectory;
import org.apache.lucene.util.Version;
import org.wltea.analyzer.lucene.IKAnalyzer;

public class HighlighterTest {

    // 高亮處理文本（以下内容纯属虚构）
    private String text = "China has lots of people,most of them are very poor.China is very big.China become strong now,but the poor people is also poor than other controry";

    // 原文高亮
    public void highlighter() throws IOException, InvalidTokenOffsetsException {

        TermQuery termQuery = new TermQuery(new Term("field", "china"));
        TokenStream tokenStream = new SimpleAnalyzer(Version.LUCENE_43)
                .tokenStream("field", new StringReader(text));

        QueryScorer queryScorer = new QueryScorer(termQuery);
        Highlighter highlighter = new Highlighter(queryScorer);
        highlighter.setTextFragmenter(new SimpleSpanFragmenter(queryScorer));
        System.out.println(highlighter.getBestFragment(tokenStream, text));
    }

    // 使用CSS進行高亮顯示處理
    public void highlighter_CSS(String searchText) throws ParseException,
            IOException, InvalidTokenOffsetsException {

        // 創建查詢
        QueryParser queryParser = new QueryParser(Version.LUCENE_43, "field",
                new SimpleAnalyzer(Version.LUCENE_43));
        Query query = queryParser.parse(searchText);

        // 自定义标注高亮文本标签
        SimpleHTMLFormatter htmlFormatter = new SimpleHTMLFormatter(
                "<span style=\"backgroud:red\">", "</span>");
        // 语汇单元化
        TokenStream tokenStream = new SimpleAnalyzer(Version.LUCENE_43)
                .tokenStream("field", new StringReader(text));

        // 創建QueryScoer
        QueryScorer queryScorer = new QueryScorer(query, "field");

        Highlighter highlighter = new Highlighter(htmlFormatter, queryScorer);
        highlighter.setTextFragmenter(new SimpleSpanFragmenter(queryScorer));

        System.out.println(highlighter.getBestFragments(tokenStream, text, 4,
                "..."));
    }

    // 高亮顯示搜索結果
    public void highlighter_SR(String field, String searchText)
            throws IOException, ParseException, InvalidTokenOffsetsException {

        //本次示例为了简便直接使用之前实验建立的索引
        Directory directory = new SimpleFSDirectory(new File("E://MyIndex"));
        IndexReader reader = DirectoryReader.open(directory);// 读取目录
        IndexSearcher search = new IndexSearcher(reader);// 初始化查询组件
        QueryParser parser = new QueryParser(Version.LUCENE_43, field,
                new IKAnalyzer(true));

        Query query = parser.parse(searchText);

        TopDocs td = search.search(query, 10000);// 获取匹配上元素的一个docid
        ScoreDoc[] sd = td.scoreDocs;// 加载所有的Documnet文档

        System.out.println("本次命中数据:" + sd.length);
        QueryScorer scorer = new QueryScorer(query, "content");

        Highlighter highlighter = new Highlighter(scorer);
        highlighter.setTextFragmenter(new SimpleSpanFragmenter(scorer));

        for (ScoreDoc scoreDoc : sd) {
            Document document = search.doc(scoreDoc.doc);
            String content = document.get("content");
            TokenStream tokenStream = TokenSources.getAnyTokenStream(
                    search.getIndexReader(), scoreDoc.doc, "content", document,
                    new IKAnalyzer(true));
            System.out.println(highlighter
                    .getBestFragment(tokenStream, content));
        }
    }
}

测试代码：

@Test
public void test() throws IOException, InvalidTokenOffsetsException,
        ParseException {
    // fail("Not yet implemented");
    HighlighterTest highlighterTest = new HighlighterTest();
    highlighterTest.highlighter();
    highlighterTest.highlighter_CSS("china");
    highlighterTest.highlighter_CSS("poor");
    highlighterTest.highlighter_SR("content", "床前明月光");
}

测试结果：

<B>China</B> has lots of people,most of them are very poor。<B>China</B> is very big.<B>China</B> become strong now,but the poor people is also poor than other controry
<span style="backgroud:red">China</span> has lots of people,most of them are very poor。<span style="backgroud:red">China</span> is very big.<span style="backgroud:red">China</span> become strong now,but the poor people is also poor than other controry
China has lots of people,most of them are very <span style="backgroud:red">poor</span>。China is very big.China become strong now,but the <span style="backgroud:red">poor</span> people is also <span style="backgroud:red">poor</span> than other controry
本次命中数据:1
<B>床</B><B>前</B><B>明月光</B>，疑是地上霜