es的优势

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前言

总结es优势

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一、es为什么比mysql快

1. es是一个基于Lucene引擎库，基于内存，查询速度比mysql，这个是在存储方式的比较
2. 第二是数据存储方式，倒排索引，存储方式，可以快速找到数据的大概位置，文档列表，利用二叉查询方法进行寻找方式
3. es支持复杂的语法格式，寻找附近酒店，进行分页
4. 缺点
5. 过于占内存

二、使用步骤

1.引入库

代码如下（示例）：

package com.cn;import com.alibaba.fastjson.JSON;
import com.cn.mapper.ESMapper;
import com.cn.pojo.Hotel;
import com.cn.pojo.TbHotel;
import com.cn.pojo.vo.TbHotelVo;
import org.apache.http.HttpHost;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.GetIndexRequest;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.unit.DistanceUnit;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.junit.Test;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;@RunWith(SpringRunner.class)
@SpringBootTest
public class EsTest {@Autowiredprivate RestHighLevelClient client;@Autowiredprivate ESMapper esMapper;@BeforeEachvoid setUp() {this.client = new RestHighLevelClient(RestClient.builder(HttpHost.create("http://192.168.36.128:9200")));}@AfterEachvoid tearDown() throws IOException {this.client.close();}/*** 判断索引是否存在* @throws IOException*/@Testpublic void  getIndexRequest() throws IOException {GetIndexRequest request = new GetIndexRequest("tiantian");boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);System.out.println(exists?"不能再":"我问");}/*** 批量导入文档* @throws IOException*/@Testpublic void c() throws IOException {List<Hotel> hotels = new ArrayList<>();for (int i = 0; i < 50; i++) {Hotel hotel = new Hotel();hotel.setId(Long.valueOf(i));hotel.setAge(i);hotel.setAddress("我的地址方式"+i);hotel.setTime(new Date());hotel.setName("将来"+i);hotel.setLatLon("23.5","3"+i);hotel.setLocation("23.5","3"+i);hotels.add(hotel);}//批量导入BulkRequest bulkRequest = new BulkRequest();//转化文档for (Hotel hotel : hotels) {bulkRequest.add(new IndexRequest("tiantian").id(hotel.getId().toString()).source(JSON.toJSONString(hotel), XContentType.JSON));}//发送请求BulkResponse bulk = client.bulk(bulkRequest, RequestOptions.DEFAULT);System.out.println(bulk);}/*** 导入数据信息* @throws IOException*/@Testpublic void bulkRequest() throws IOException {BulkRequest bulkRequest = new BulkRequest();List<TbHotel> tbHotels = esMapper.selectList(null);for (TbHotel tbHotel : tbHotels) {TbHotelVo tbHotelVo = new TbHotelVo(tbHotel);bulkRequest.add(new IndexRequest("hotel").id(tbHotelVo.getId().toString()).source(JSON.toJSONString(tbHotelVo),XContentType.JSON));}client.bulk(bulkRequest,RequestOptions.DEFAULT);}/*** 查询所有文档信息* @throws IOException*/@Testpublic void testMatchAll() throws IOException {SearchRequest request = new SearchRequest("hotel");request.source().query(QueryBuilders.matchAllQuery());SearchResponse response = client.search(request, RequestOptions.DEFAULT);for (SearchHit hit : response.getHits().getHits()) {String source = hit.getSourceAsString();System.out.println(source);}}/*** 准确查询* @throws IOException*/@Testpublic void matchQuery() throws IOException {SearchRequest request = new SearchRequest("hotel");request.source().query(QueryBuilders.termQuery("price","189"));SearchResponse response = client.search(request, RequestOptions.DEFAULT);for (SearchHit hit : response.getHits().getHits()) {String sourceAsString = hit.getSourceAsString();System.out.println(sourceAsString);}}/*** 布尔查询方式* 查询名字叫做如家* 价格200* 地址在上海*/@Testpublic void boolQuery() throws IOException {SearchRequest request = new SearchRequest("hotel");BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();boolQuery.mustNot(QueryBuilders.rangeQuery("price").gte("400"));boolQuery.must(QueryBuilders.matchQuery("city","上海"));boolQuery.must(QueryBuilders.matchQuery("name","如家"));request.source().query(boolQuery);for (SearchHit hit : client.search(request, RequestOptions.DEFAULT).getHits().getHits()) {String sourceAsString = hit.getSourceAsString();System.out.println(sourceAsString);}}/*** bool查询方式* @throws IOException*/@Testpublic void testBoole() throws IOException {SearchRequest request = new SearchRequest("hotel");BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();boolQuery.must(QueryBuilders.matchQuery("name","如家"));request.source().query(boolQuery);for (SearchHit hit : client.search(request, RequestOptions.DEFAULT).getHits()) {System.out.println(hit.getSourceAsString());}}/*** 根据经纬度查询方式* @throws IOException*/@Testpublic void geoPoint() throws IOException {SearchRequest request = new SearchRequest("hotel");request.source().sort(SortBuilders.geoDistanceSort("lonAndLat",new GeoPoint("31.2,121.5")).order(SortOrder.ASC).unit(DistanceUnit.KILOMETERS));SearchResponse response = client.search(request, RequestOptions.DEFAULT);for (SearchHit hit : response.getHits().getHits()) {TbHotel tbHotel = JSON.parseObject(hit.getSourceAsString(), TbHotel.class);System.out.println(tbHotel.getLonAndLat());}}@Testpublic void testMat() throws IOException {SearchRequest request = new SearchRequest("hotel");request.source().query(QueryBuilders.matchQuery("name","如家"));SearchResponse response = client.search(request, RequestOptions.DEFAULT);for (SearchHit hit : response.getHits().getHits()) {System.out.println(hit.getSourceAsString());}}
}

2. es查询语法

代码如下（示例）：

//添加索引
PUT /tiantian
{"mappings": {"properties": {"name":{"type": "text", "analyzer": "ik_smart"},"age":{"type": "integer", "index": false}}}
}//查询索引
GET /tiantian//查询文档信息
GET /tiantian/_doc/1//添加字段信息
PUT /tiantian/_mapping
{"properties":{"address":{"type":"text","index":false}}
}//添加数据文档数据信息
POST /tiantian/_doc/1
{"address":"巴黎","name":"太牛龙","age":123
}//查询经纬度
GET /hotel/_search
{"query": {"match_all": {}},"sort": [{"price": {"order": "desc"}},{"_geo_distance": {"lonAndLat": {"lat": 31.2,"lon": 121.5},"order": "asc"}}]
}POST /hotel/_update/1902197537
{"doc": {"isAD": true}
}
POST /hotel/_update/2056126831
{"doc": {"isAD": true}
}
POST /hotel/_update/1989806195
{"doc": {"isAD": true}
}
POST /hotel/_update/2056105938
{"doc": {"isAD": true}
}GET /hotel/_search
{"query": {"function_score": {"query": {"match": {"name": "外滩"}},"functions": [{"filter": { "term": {"id": "1"}},"weight": 10}],"boost_mode": "multiply"}},"from": 1,"size": 10
}GET /hotel/_search
{"query": {"function_score": {"query": {"match": {"name": "如家"}},"functions": [{"filter": {"term": {"name": "339952837"}}, "weight": 10}],"boost_mode": "sum"}}
}GET /hotel/_search
{"query": {"match_all": {}}
}GET /hotelGET /hotel/_search
{"size": 0, "aggs": {"brandAgg": {"terms": {"field": "brand.keyword"}}}}GET /hotel/_search
{"query": {"match": {"name": "东方明珠"}}
}

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三，api功能

@Overridepublic PageResult search(RequestParams params) throws IOException {//1.准备发送SearchRequest request = new SearchRequest("hotel");//2.准备布尔条件BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();//3.判断是否存在String key = params.getKey();if (key==null || "".equals(key)){boolQuery.must(QueryBuilders.matchAllQuery());}else {boolQuery.must(QueryBuilders.matchQuery("name",key));}Integer size = params.getSize();Integer page = params.getPage();request.source().from((page - 1) * size).size(size);request.source().query(boolQuery);String location = params.getLocation();//得出具体路径if (location!=null && !location.equals("")){request.source().sort(SortBuilders.geoDistanceSort("lonAndLat",new GeoPoint(location)).order(SortOrder.ASC).unit(DistanceUnit.KILOMETERS));}//相关性算法FunctionScoreQueryBuilder scoreQuery = QueryBuilders.functionScoreQuery(boolQuery,new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{new FunctionScoreQueryBuilder.FilterFunctionBuilder(QueryBuilders.termQuery("isAD", true),ScoreFunctionBuilders.weightFactorFunction(10))});request.source().query(scoreQuery);SearchResponse response = client.search(request, RequestOptions.DEFAULT);return  handleResponse(response);}

根据经纬度查询方式

//得出具体路径if (location!=null && !location.equals("")){request.source().sort(SortBuilders.geoDistanceSort("lonAndLat",new GeoPoint(location)).order(SortOrder.ASC).unit(DistanceUnit.KILOMETERS));}

相关性算法

       //相关性算法FunctionScoreQueryBuilder scoreQuery = QueryBuilders.functionScoreQuery(boolQuery,new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{new FunctionScoreQueryBuilder.FilterFunctionBuilder(QueryBuilders.termQuery("isAD", true),ScoreFunctionBuilders.weightFactorFunction(10))});

总结

1. es高效，速度快，基于lu的内存数据库，采用倒序索引的方式，倒叙索引好处，我们之前数据库根据id找到值，倒排索引的方式，es默认创建索引，根据值找到，对应的文档列表，文档列表根据二分查找方式，找到对应的值
2. es强大的api功能普通基于内存的数据库的方式，比如redis功能，适合做缓存，没有强大的api，不能做复杂的功能，es有强大api，分页，查询，联合查询，经纬度查询，相关性质查询方式