第六步：Lucene查詢索引

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:\"美國\"";//包含「美國」
		 * String queryString="NOT title:\"美國\" AND title:\"國\"";//不包含 「美國」 可是包含 「國」
		 * String queryString="title:\"中\" AND title:\"國人\"";//即包含 「中」 又包含 」國人「
		 * String queryString="title:\"張三\" OR title:\"李四\"";//包含 「張三」 或 」李四「
		 * String queryString="id:[1 TO 5]";//查詢 1<=id<=5
		 * String queryString="id:{1 TO 5}";//查詢 1<id<5
		 * String queryString="title:\"中國\" AND NOT title:\"張三\" AND id:[1 TO 5]";
		 * String queryString="title:(中國 張三)";即包含 「中國」 又包含 」張三「
		 ---------------------------------------------------------------------------------*/
		String queryString="title:\"中國\"";
		
		Analyzer analyzer = new StandardAnalyzer();  //StandardAnalyzer:漢字一個一個字拆分索引
        Directory dir = FSDirectory.open(Paths.get("E:\\LuceneIndex")); //獲取索引存儲的位置
        IndexReader reader = DirectoryReader.open(dir);
        IndexSearcher is = new IndexSearcher(reader);
        QueryParser parser=new QueryParser("", analyzer);
        parser.setDefaultOperator(Operator.AND);//默認狀態下，空格被認爲是OR的關係，設置爲空格爲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("總共匹配多少個：" + topDocs.totalHits);
        //獲取查詢結果集
        ScoreDoc[] hits = topDocs.scoreDocs;
        //遍歷結果集
        for (ScoreDoc scoreDoc : hits) {
            //System.out.println("匹配得分：" + scoreDoc.score);
            //System.out.println("文檔索引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();        
	}
}