package searchfileexample;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.io.IOException;
import java.io.StringReader;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Hits;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.highlight.Highlighter;
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.analysis.standard.StandardAnalyzer;
public class MyHighLighterServlet extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=GB18030";
private String indexPath = "C:\\index";
private Analyzer analyzer;
private IndexSearcher searcher;
//Initialize global variables
public void init() throws ServletException {
analyzer = new StandardAnalyzer();
}
public void createIndex() throws IOException { // 该方法建立索引
IndexWriter writer = new IndexWriter(indexPath,analyzer,true);
Document docA = new Document();
String fileTextA = "因为火烧云总是燃烧着消失在太阳冲下地平线的时刻，然后便是宁静的自然的天籁，没有谁会在这样的时光的镜片里伤感自语，因为灿烂给人以安静的舒适感。";
Field fieldA = new Field("contents", fileTextA, Field.Store.YES,Field.Index.TOKENIZED);
docA.add(fieldA);
Document docB = new Document();
String fileTextB = "因为带有以伤痕为代价的美丽风景总是让人不由地惴惴不安，紧接着袭面而来的抑或是病痛抑或是灾难，没有谁会能够安逸着恬然，因为模糊让人撕心裂肺地想呐喊。";
Field fieldB = new Field("contents", fileTextB, Field.Store.YES,Field.Index.TOKENIZED);
docB.add(fieldB);
Document docC = new Document();
String fileTextC = "我喜欢上了一个人孤独地行游，在梦与海洋的交接地带炽烈燃烧着。"+
"因为，一条孤独的鱼喜欢上了火焰的颜色，真是荒唐地不合逻辑,原因。";
Field fieldC = new Field("contents", fileTextC, Field.Store.YES,Field.Index.TOKENIZED);
docC.add(fieldC);
writer.addDocument(docA);
writer.addDocument(docB);
writer.addDocument(docC);
writer.optimize();
writer.close();
}
public void search(String fieldName,String keyword,PrintWriter out) throws CorruptIndexException, IOException, ParseException{ // 检索的方法，并实现高亮显示
searcher = new IndexSearcher(indexPath);
QueryParser queryParse = new QueryParser(fieldName, analyzer); // 构造QueryParser，解析用户输入的检索关键字
Query query = queryParse.parse(keyword);
Hits hits = searcher.search(query);
for(int i=0;i<hits.length();i++){
Document doc = hits.doc(i);
String text = doc.get(fieldName);
SimpleHTMLFormatter simpleHTMLFormatter = new SimpleHTMLFormatter("<font color='red'>", "</font>");
Highlighter highlighter = new Highlighter(simpleHTMLFormatter,new QueryScorer(query));
highlighter.setTextFragmenter(new SimpleFragmenter(text.length()));
if (text != null) {
TokenStream tokenStream = analyzer.tokenStream(fieldName,new StringReader(text));
String highLightText = highlighter.getBestFragment(tokenStream, text);
System.out.println("★高亮显示第 "+(i+1) +" 条检索结果如下所示：");
out.println(highLightText);
}
}
searcher.close();
}
//Process the HTTP Get request
public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>MyHighLighterServlet</title></head>");
out.println("<body bgcolor=\"#ffffff\">");
try {
createIndex();
search("contents", "因为",out);
} catch (CorruptIndexException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
}
out.println("</body></html>");
}
//Clean up resources
public void destroy() {
}
}