Lucene实现搜索结果命中关键字高亮显示

     使用lucene实现搜索结果 命中关键字高亮显示，大致流程与lucene 建立文件索引和针对索引进行搜索（lucene2.2版本）介绍的一致，只需在代码里稍作修改。    1.索引生成过程：（红色为修改部分，针对需要进行高亮显示索引内容，进行分词与关键字位置索引）

package demo.example.searcher; import java.io.*; import java.util.*; import org.apache.lucene.analysis.standard.*; import org.apache.lucene.index.*; import org.apache.lucene.document.*; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class Indexer { private static Log log = LogFactory.getLog(Indexer.class); public static void main(String[] args) throws Exception { File indexDir = new File("C:\\index"); File dataDir = new File("C:\\lucene\\src"); long start = new Date().getTime(); int numIndexed = index(indexDir, dataDir); long end = new Date().getTime(); System.out.println("use:" + (end - start)); } public static int index(File indexDir, File dataDir) { int ret = 0; try { IndexWriter writer = new IndexWriter(indexDir, new StandardAnalyzer(), true); writer.setUseCompoundFile(false); indexDirectory(writer, dataDir); ret = writer.docCount(); writer.optimize(); writer.close(); } catch (Exception e) { e.printStackTrace(); } return ret; } public static void indexDirectory(IndexWriter writer, File dir) { try { File[] files = dir.listFiles(); for (File f : files) { if (f.isDirectory()) { indexDirectory(writer, f); } else { indexFile(writer, f); } } } catch (Exception e) { e.printStackTrace(); } } public static void indexFile(IndexWriter writer, File f) { try { System.out.println("Indexing:" + f.getCanonicalPath()); Document doc = new Document(); Reader txtReader = new FileReader(f); doc.add(new Field("contents", txtReader，Field.TermVector.WITH_POSITIONS_OFFSETS)); doc.add(new Field("filename", f.getCanonicalPath(), Field.Store.YES, Field.Index.UN_TOKENIZED)); writer.addDocument(doc); } catch (Exception e) { e.printStackTrace(); } } }

2.搜索过程，红色的为修改部分，需要highlight和analysis的lucene的jar文件  

package demo.example.searcher; import java.util.*; import org.apache.lucene.search.highlight.*; import org.apache.lucene.analysis.*; import org.apache.lucene.search.*; import org.apache.lucene.queryParser.*; import org.apache.lucene.analysis.standard.*; import org.apache.lucene.document.*; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class Searcher { private static Log log = LogFactory.getLog(Searcher.class); public static void main(String[] args) { String indexDir = "C:\\index"; String q = "查询关键字"; search(indexDir, q); } public static void search(String indexDir, String q) { try { IndexSearcher is = new IndexSearcher(indexDir); QueryParser queryParser = new QueryParser("contents", new StandardAnalyzer()); Query query = queryParser.parse(q); long start = new Date().getTime(); Hits hits = is.search(query); long end = new Date().getTime(); System.out.println("use:" + (end - start));

 

SimpleHTMLFormatter formatter = new SimpleHTMLFormatter("<strong><font color='red'>", "</font></strong>");    SimpleFragmenter fragmenter = new SimpleFragmenter(60);

 

   Highlighter highlighter = new Highlighter(formatter, new QueryScorer(q));    highlighter.setTextFragmenter(fragmenter);

 

   int maxNumFragmentsRequired = 10;    String fragmentSeparator = "";    TermPositionVector tpv = null;    TokenStream tokenstream = null;

 

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

 

int id = hits.id(i);

 

System.out.println("The right file:" + doc.get("filename"));

 

tpv = (TermPositionVector) is.getIndexReader().getTermFreqVector(id, "contents");

 

 tokenstream = TokenSources.getTokenStream(tpv);

 

String result = highlighter.getBestFragments(tokenstream, doc.get("contents"),        maxNumFragmentsRequired, fragmentSeparator)

 

System.out.println("The right file context is :" + result);

 

} } catch (Exception e) { e.printStackTrace(); } } }

   在输出结果中，文件内容中命中的关键字被加上了

"<strong><font color='red'>", "</font></strong>"

   在网页中显示内容，即为黑体红字显示效果。