【Lucene3.6.2入门系列】第11节_高亮

完整版见https://jadyer.github.io/2013/08/20/lucene-highlighter/

package com.jadyer.lucene;import java.io.File;import java.io.IOException;import org.apache.lucene.analysis.Analyzer;import org.apache.lucene.document.Document;import org.apache.lucene.document.Field;import org.apache.lucene.index.IndexReader;import org.apache.lucene.index.IndexWriter;import org.apache.lucene.index.IndexWriterConfig;import org.apache.lucene.queryParser.MultiFieldQueryParser;import org.apache.lucene.queryParser.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.search.highlight.Formatter;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.store.Directory;import org.apache.lucene.store.FSDirectory;import org.apache.lucene.util.Version;import org.apache.tika.Tika;import com.chenlb.mmseg4j.analysis.MMSegAnalyzer;/** * 【Lucene3.6.2入门系列】第11节_高亮 * @see 高亮功能属于Lucene的扩展功能(或者叫做贡献功能) * @see 其所需jar位于Lucene-3.6.2.zip中的/contrib/highlighter/文件夹中 * @see 本例中需要以下4个jar * @see lucene-core-3.6.2.jar * @see lucene-highlighter-3.6.2.jar * @see mmseg4j-all-1.8.5-with-dic.jar * @see tika-app-1.4.jar * @create Aug 7, 2013 11:37:10 AM * @author 玄玉<http://blog.csdn.net/jadyer> */public class HelloHighLighter {private Directory directory;private IndexReader reader;public HelloHighLighter(){Document doc = null;IndexWriter writer = null;try{directory = FSDirectory.open(new File("myExample/myIndex/"));writer = new IndexWriter(directory, new IndexWriterConfig(Version.LUCENE_36, new MMSegAnalyzer()));writer.deleteAll();for(File myFile : new File("myExample/myFile/").listFiles()){doc = new Document();doc.add(new Field("filecontent", new Tika().parse(myFile))); //Field.Store.NO,Field.Index.ANALYZEDdoc.add(new Field("filepath", myFile.getAbsolutePath(), Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS));writer.addDocument(doc);}}catch(Exception e) {e.printStackTrace();}finally{if(null != writer){try {writer.close();} catch (IOException ce) {ce.printStackTrace();}}}}/** * 获取IndexSearcher实例 */private IndexSearcher getIndexSearcher(){try {if(reader == null){reader = IndexReader.open(directory);}else{//if the index was changed since the provided reader was opened, open and return a new reader; else,return null//如果当前reader在打开期间index发生改变,则打开并返回一个新的IndexReader,否则返回nullIndexReader ir = IndexReader.openIfChanged(reader);if(ir != null){reader.close(); //关闭原readerreader = ir;    //赋予新reader}}return new IndexSearcher(reader);}catch(Exception e) {e.printStackTrace();}return null; //发生异常则返回null}/** * 高亮搜索 * @see 高亮搜索时,不建议把高亮信息存到索引里,而是搜索到内容之后再进行高亮处理 * @see 这里用的是MMSeg4j中文分词器,有关其介绍详见http://blog.csdn.net/jadyer/article/details/10049525 * @param expr 搜索表达式 */public void searchByHignLighter(String expr){Analyzer analyzer = new MMSegAnalyzer();IndexSearcher searcher = this.getIndexSearcher();//搜索多个FieldQueryParser parser = new MultiFieldQueryParser(Version.LUCENE_36, new String[]{"filepath", "filecontent"}, analyzer);try {Query query = parser.parse(expr);TopDocs tds = searcher.search(query, 50);for(ScoreDoc sd : tds.scoreDocs){Document doc = searcher.doc(sd.doc);//获取文档内容String filecontent = new Tika().parseToString(new File(doc.get("filepath")));System.out.println("搜索到的内容为[" + filecontent + "]");//开始高亮处理QueryScorer queryScorer = new QueryScorer(query);Fragmenter fragmenter = new SimpleSpanFragmenter(queryScorer, filecontent.length());Formatter formatter = new SimpleHTMLFormatter("<span style='color:red'>", "</span>");Highlighter hl = new Highlighter(formatter, queryScorer);hl.setTextFragmenter(fragmenter);System.out.println("高亮后的内容为[" + hl.getBestFragment(analyzer, "filecontent", filecontent) + "]");}} catch (Exception e) {e.printStackTrace();} finally {if(null != searcher){try {searcher.close(); //记得关闭IndexSearcher} catch (IOException e) {e.printStackTrace();}}}}/** * 高亮的使用方式 * @see 这里用的是MMSeg4j中文分词器,有关其介绍详见http://blog.csdn.net/jadyer/article/details/10049525 */private static void testHighLighter(){String fieldName = "myinfo"; //这个可以随便写,就是起个标识的作用String text = "我来自中国黑龙江省哈尔滨市巴彦县兴隆镇长春乡民权村4队";QueryParser parser = new QueryParser(Version.LUCENE_36, fieldName, new MMSegAnalyzer());try {//MMSeg4j的new MMSegAnalyzer()默认只会对'中国'和'兴隆'进行分词,所以这里就只高亮它们俩了Query query = parser.parse("中国 兴隆");//针对查询出来的文本,查询其评分,以便于能够根据评分决定显示情况QueryScorer queryScorer = new QueryScorer(query);//对字符串或文本进行分段,SimpleSpanFragmenter构造方法的第二个参数可以指定高亮的文本长度,默认为100Fragmenter fragmenter = new SimpleSpanFragmenter(queryScorer);//高亮时的高亮格式,默认为<B></B>,这里指定为红色字体Formatter formatter = new SimpleHTMLFormatter("<span style='color:red'>", "</span>");//Highlighter专门用来做高亮显示//该构造方法还有一个参数为Encoder,它有两个实现类DefaultEncoder和SimpleHTMLEncoder//SimpleHTMLEncoder可以忽略掉HTML标签,而DefaultEncoder则不会忽略HTML标签Highlighter hl = new Highlighter(formatter, queryScorer);hl.setTextFragmenter(fragmenter);System.out.println(hl.getBestFragment(new MMSegAnalyzer(), fieldName, text));} catch (Exception e) {e.printStackTrace();}}/** * 小测试一下 */public static void main(String[] args) {//测试高亮的基本使用效果HelloHighLighter.testHighLighter();//测试高亮搜索的效果(测试前记得在myExample/myFile/文件夹中准备一个或多个内容包含"依赖"的doc或pdf的等文件)new HelloHighLighter().searchByHignLighter("依赖");}}