package cn.mylucene;import java.io.IOException;
import java.nio.file.Paths;import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.queryparser.classic.ParseException;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.queryparser.classic.QueryParser.Operator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.SearcherFactory;
import org.apache.lucene.search.SearcherManager;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.SortField.Type;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.FSDirectory;public class SearchIndex {public static void main(String[] args) throws IOException, ParseException {        String queryString="title:\"国\"";      Analyzer analyzer = new StandardAnalyzer();  //StandardAnalyzer:汉字一个一个字拆分索引IndexSearcher is = getIndexSearcher();QueryParser parser=new QueryParser("", analyzer);parser.setDefaultOperator(Operator.AND);//默认状态下，空格被认为是OR的关系，设置为空格为ANDQuery query = parser.parse(queryString);//排序Sort sort = new Sort(new SortField("dt", Type.LONG, true));TopDocs topDocs = is.search(query, 20,sort);System.out.println("总共匹配多少个：" + topDocs.totalHits);//获取查询结果集ScoreDoc[] hits = topDocs.scoreDocs;int pageSize=5;//每页显示记录数int curPage=2;//当前页//查询起始记录位置int begin = pageSize * (curPage - 1);//查询终止记录位置int end = Math.min(begin + pageSize, hits.length);//遍历结果集for(int i=begin;i<end;i++) {int docID = hits[i].doc;Document document = is.doc(docID);System.out.println(document.get("id")+"-"+document.get("name")+"-"+document.get("dt")+"-"+document.get("title"));}closeIndexSearcher(is);        } /** 解决：实现实时搜索功能* 解决：在读取索引文件内容时，索引文件的打开操作IndexSearcher是个非常耗时耗资源的操作* */private static byte[] synchronized_r = new byte[0];private static SearcherManager searcherManager = null;private static IndexSearcher getIndexSearcher() throws IOException {IndexSearcher indexSearcher = null;//保证在同一时刻最多只有一个线程执行该段代码synchronized (synchronized_r) {if(searcherManager == null) {searcherManager = new SearcherManager(FSDirectory.open(Paths.get("E:\\LuceneIndex")), new SearcherFactory());}/** 这个方法同DirectoryReader.openIfChanged(dirReader)效果一样，其实底层还是调用的该方法实现的* DirectoryReader.openIfChanged(dirReader)可以判断当前Reader对象的索引有没有被修改过* 如果索引文件被更新过则重新加载该索引目录* 但是这个时候的重新加载则比单纯的open(indexPath)要高效很多* 它只是重新加载被更新过的文档，而单纯的open则是加载全部的文档* */searcherManager.maybeRefresh();//借用一个IndexSearcher对象的引用，记住该对象用完之后要归还的，有借有还再借不难indexSearcher = searcherManager.acquire();}return indexSearcher;}private static void closeIndexSearcher(IndexSearcher indexSearcher) throws IOException {if(indexSearcher != null) {searcherManager.release(indexSearcher);//归还从SearcherManager处借来的IndexSearcher对象}indexSearcher = null;}
}