1.引入
全文检索简介: 非结构化数据又一种叫法叫全文数据。从全文数据（文本）中进行检索就叫全文检索。
2.数据库搜索的弊端
案例 ：
select * from product where product like ‘苹果’g
1、 使用like，会导致索引失效
（没有索引时）速度相对慢
2、 搜索效果不好
3、 没有相关度排序
3.全文解锁实现原理
4.简单使用
4.1.创建索引与搜索索引
首先导入jar包
代码:
package com.day02.lucene; import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.FieldType;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
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.apache.lucene.util.Version;
import org.junit.Test; import java.io.File;
import java.io.IOException; /**
* Created by Administrator on 2/10.
*/
public class HelloLucene {
//索引地址目录
private String file = "E:\\lucene\\indexOne";
//索引版本配置
private Version matchVersion = Version.LUCENE_4_10_4;
//案例文档
private String doc1 = "Hello world Hello";
private String doc2 = "Hello java world Hello Hello";
private String doc3 = "Hello lucene world"; /**
* 创建索引代码
*
* @throws IOException
*/
@Test
public void testCreateIndex() throws IOException {
System.out.println("-----测试开始------");
//创建索引目录地址对象
Directory directory = FSDirectory.open(new File(file));
//指定分词规则
Analyzer analyzer = new StandardAnalyzer();
//创建索引配置对象
IndexWriterConfig conf = new IndexWriterConfig(matchVersion, analyzer);
//创建索引对象
IndexWriter indexWriter = new IndexWriter(directory, conf);
//创建文本属性
FieldType fieldType = new FieldType();
fieldType.setStored(true);//存储数据
fieldType.setIndexed(true);//添加索引 //创建要添加的文本对象
Document document1 = new Document();
document1.add(new Field("doc", doc1, fieldType));
//添加索引
indexWriter.addDocument(document1); //创建要添加的文本对象
Document document2 = new Document();
document2.add(new Field("doc", doc2, fieldType));
//添加索引
indexWriter.addDocument(document2); //创建要添加的文本对象
Document document3 = new Document();
document3.add(new Field("doc", doc3, fieldType));
//添加索引
indexWriter.addDocument(document3); //关闭资源
indexWriter.close();
} /**
*获取索引
* 1.创建查询分析器(QueryParser),使用查询分析器得到查询对象
* 2.使用索引搜索器(IndexSearcher).search(查询对象, 获取的多少条数据),使用索引搜索器获得文档结果集(TopDocs)
* 3.遍历文档结果集获取文档id
* 4.使用IndexSearcher通过文档id获取文档对象,并获取文档具体字段值
*/
String key = "lucene"; @Test
public void testSearchIndex() throws IOException, ParseException {
System.out.println("-----测试开始------");
//1.创建索引目录地址对象
Directory directory = FSDirectory.open(new File(file));
//2.创建目录阅读器
IndexReader indexReader = DirectoryReader.open(directory);
//3.创建索引搜索器
IndexSearcher indexSearcher = new IndexSearcher(indexReader);
//需要查询的字段
String query = "doc";
//4.创建分词器
StandardAnalyzer standardAnalyzer = new StandardAnalyzer();
//5.创建查询分析器
QueryParser queryParser = new QueryParser(query, standardAnalyzer);
//6.使用查询分析器(查询关键字)获取对应的对象
Query parse = queryParser.parse(key);
//7.获取查询结果
int n = 1000;//最大返回对象数
TopDocs topDocs = indexSearcher.search(parse, n);
//8.获取总天数
int totalHits = topDocs.totalHits;
System.out.println("totalHits=>" + totalHits);
//9.获取查询返回结果集
ScoreDoc[] scoreDocs = topDocs.scoreDocs;
//10.遍历结果集
for (ScoreDoc scoreDoc : scoreDocs) {
//获取文档主键
int docId = scoreDoc.doc;
System.out.println("docId=" + docId);
//通过文档Id获取文档对象
Document doc = indexSearcher.doc(docId);
//获取文档值
String docValue = doc.get("doc");//根据存放的key
System.out.println("docValue=" + docValue);
}
}
}
创建索引测试结果如下:
执行索引搜索结果如下图:
5.执行流程
