检索结果高亮对于用户的体验度和友好度非常重要，可以快速标记出用户检索对关键词。本例中的索引仍使用上一篇博客（Lucene查询索引）中创建的索引，代码高亮参考了Lucene4.x高亮 fast高亮 前端高亮。

实现效果：

核心代码

package ucas.ir.lucene;

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

import javax.print.Doc;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.core.KeywordAnalyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.highlight.Fragmenter;
import org.apache.lucene.search.highlight.Highlighter;
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.FSDirectory;
import org.apache.lucene.util.Version;
import org.wltea.analyzer.lucene.IKAnalyzer;

public class IndexSearch {

    public static void main(String[] args) {
        Directory directory = null;
        try {
            File indexpath = new File("/Users/yp/Documents/workspace/UCASIR/WebContent/index");
            if (indexpath.exists() != true) {
                indexpath.mkdirs();
            }
            // 设置要查询的索引目录
            directory = FSDirectory.open(indexpath);
            // 创建indexSearcher
            DirectoryReader dReader = DirectoryReader.open(directory);
            IndexSearcher searcher = new IndexSearcher(dReader);
            // 设置分词方式
            Analyzer analyze2 = new StandardAnalyzer(Version.LUCENE_43);// 标准分词
            Analyzer analyzer = new IKAnalyzer();

            // 设置查询域
            String field="news_title";
            QueryParser parser = new QueryParser(Version.LUCENE_43, field, analyzer);
            // 查询字符串
            Query query = parser.parse("阿法狗");

            QueryScorer scorer=new QueryScorer(query,field);
            SimpleHTMLFormatter fors=new SimpleHTMLFormatter("<span style=\"color:red;\">", "</span>");
            Highlighter highlighter=new Highlighter(fors, scorer);

            System.out.println("query:" + query.toString());
            // 返回前10条
            TopDocs topDocs = searcher.search(query, 10);
            if (topDocs != null) {
                System.out.println("符合条件第文档总数：" + topDocs.totalHits);

                for (int i = 0; i < topDocs.scoreDocs.length; i++) {
                    Document doc = searcher.doc(topDocs.scoreDocs[i].doc);
                    TokenStream tokenStream=TokenSources.getAnyTokenStream(searcher.getIndexReader(), topDocs.scoreDocs[i].doc, field, analyzer);
                    Fragmenter  fragment=new SimpleSpanFragmenter(scorer);
                    highlighter.setTextFragmenter(fragment);
                    //高亮news_title域
                    String str=highlighter.getBestFragment(tokenStream, doc.get("news_title"));//获取高亮的片段，可以对其数量进行限制
                    System.out.println("高亮title："+str);
                    tokenStream=TokenSources.getAnyTokenStream(searcher.getIndexReader(), topDocs.scoreDocs[i].doc, "news_summary", analyzer);
                    str=highlighter.getBestFragment(tokenStream, doc.get("news_summary"));//获取高亮的片段，可以对其数量进行限制
                    System.out.println("高亮summary："+str);
                }
            }
            directory.close();
            dReader.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

结果：