第六步：Lucene查询索引

package cn.harmel.lucene;

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.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
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.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.Directory;
import org.apache.lucene.store.FSDirectory;

public class SearchIndex {
	public static void main(String[] args) throws IOException, ParseException {		
		/*---------------------------------------------------------------------------------
		 * String queryString="title:\"美国\"";//包含“美国”
		 * String queryString="NOT title:\"美国\" AND title:\"国\"";//不包含 “美国” 可是包含 “国”
		 * String queryString="title:\"中\" AND title:\"国人\"";//即包含 “中” 又包含 ”国人“
		 * String queryString="title:\"张三\" OR title:\"李四\"";//包含 “张三” 或 ”李四“
		 * String queryString="id:[1 TO 5]";//查询 1<=id<=5
		 * String queryString="id:{1 TO 5}";//查询 1<id<5
		 * String queryString="title:\"中国\" AND NOT title:\"张三\" AND id:[1 TO 5]";
		 * String queryString="title:(中国 张三)";即包含 “中国” 又包含 ”张三“
		 ---------------------------------------------------------------------------------*/
		String queryString="title:\"中国\"";
		
		Analyzer analyzer = new StandardAnalyzer();  //StandardAnalyzer:汉字一个一个字拆分索引
        Directory dir = FSDirectory.open(Paths.get("E:\\LuceneIndex")); //获取索引存储的位置
        IndexReader reader = DirectoryReader.open(dir);
        IndexSearcher is = new IndexSearcher(reader);
        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AND
        Query 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;
        //遍历结果集
        for (ScoreDoc scoreDoc : hits) {
            //System.out.println("匹配得分：" + scoreDoc.score);
            //System.out.println("文档索引ID：" + scoreDoc.doc);
            Document document = is.doc(scoreDoc.doc);
            System.out.println(document.get("id")+"-"+document.get("name")+"-"+document.get("dt")+"-"+document.get("title"));
        }
        reader.close();
        dir.close();        
	}
}