概述
对要搜索的信息创建Query查询对象,Lucene会根据Query查询对象生成最终的查询语法,类似关系数据库SQL语法一样,Lucene也有自己的查询语法;
可通过两种方法创建查询对象:
1.使用Lucene提供Query子类;
2.使用QueryParse解析查询表达式
TermQuery查询
通过项查询,TermQuery不使用分析器所以建议匹配不分词的Field域查询,比如订单号,分类ID号等;
指定要查询的域和要查询的关键词
package com.wn.Query;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import java.io.File;
import java.io.IOException;
/*根据域和关键词进行搜索*/
public class TermQuery {
/*查询索引库*/
public static void main(String[] args)throws IOException {
Directory directory= FSDirectory.open(new File("E:\Lucene\temp\index").toPath());
IndexReader indexReader= DirectoryReader.open(directory);
IndexSearcher indexSearcher=new IndexSearcher(indexReader);
//创建查询对象
Query query=new org.apache.lucene.search.TermQuery(new Term("fieldName","text01.txt"));
//执行查询
TopDocs topDocs=indexSearcher.search(query,10);
System.out.println("查询总数量:"+topDocs.totalHits);
//遍历查询结果
for (ScoreDoc scoreDoc:topDocs.scoreDocs){
Document document = indexSearcher.doc(scoreDoc.doc);
System.out.println(document.get("fieldName"));
System.out.println(document.get("fieldContent"));
System.out.println(document.get("fieldPath"));
System.out.println(document.get("fieldSize"));
System.out.println("====================================================");
}
//关闭资源
indexSearcher.getIndexReader().close();
}
}
效果实现
数值范围查询
package com.wn.Query;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.LongPoint;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import java.io.File;
import java.io.IOException;
public class testRangeQuery {
/*数值范围查询*/
public static void main(String[] args)throws IOException {
Directory directory= FSDirectory.open(new File("E:\Lucene\temp\index").toPath());
IndexReader indexReader= DirectoryReader.open(directory);
IndexSearcher indexSearcher=new IndexSearcher(indexReader);
//创建查询对象
Query query= LongPoint.newRangeQuery("fieldSize",0,100);
//执行查询
TopDocs topDocs=indexSearcher.search(query,10);
System.out.println("查询总数量:"+topDocs.totalHits);
//遍历查询结果
for (ScoreDoc scoreDoc:topDocs.scoreDocs){
Document document = indexSearcher.doc(scoreDoc.doc);
System.out.println(document.get("fieldName"));
System.out.println(document.get("fieldContent"));
System.out.println(document.get("fieldPath"));
System.out.println(document.get("fieldSize"));
System.out.println("====================================================");
}
//关闭资源
indexSearcher.getIndexReader().close();
}
}
效果实现
QueryParser查询
通过QueryParse也可以创建Query,QueryParser提供一个parse方法,此方法可以直接根据查询语法来查询。Query对象执行的查询语法可通过system.out.println(query);查询。
需要使用到分词器,建议创建索引时使用的分词器和查询索引时使用的分词器要一致。需要加入queryParser依赖
package com.wn.Query;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.LongPoint;
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.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.wltea.analyzer.lucene.IKAnalyzer;
import java.io.File;
import java.io.IOException;
/*搜索條件分詞*/
public class Queryparsers {
public static void main(String[] args) throws IOException, ParseException {
Directory directory= FSDirectory.open(new File("E:\Lucene\temp\index").toPath());
IndexReader indexReader= DirectoryReader.open(directory);
IndexSearcher indexSearcher=new IndexSearcher(indexReader);
//创建查询对象
QueryParser queryParser=new QueryParser("fieldContent",new IKAnalyzer());
Query query = queryParser.parse("全文检索");
//执行查询
TopDocs topDocs=indexSearcher.search(query,10);
System.out.println("查询总数量:"+topDocs.totalHits);
//遍历查询结果
for (ScoreDoc scoreDoc:topDocs.scoreDocs){
Document document = indexSearcher.doc(scoreDoc.doc);
System.out.println(document.get("fieldName"));
System.out.println(document.get("fieldContent"));
System.out.println(document.get("fieldPath"));
System.out.println(document.get("fieldSize"));
System.out.println("====================================================");
}
//关闭资源
indexSearcher.getIndexReader().close();
}
}
实现效果