一、依赖：（要根据不同版本的ES来调整依赖,否则会报错，不支持太低版本的ES，比如7.6以下的）

        <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-elasticsearch</artifactId><version>3.2.3</version></dependency><dependency><groupId>co.elastic.clients</groupId><artifactId>elasticsearch-java</artifactId><version>7.16.0</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.12.3</version></dependency>

二、定义实体类：

package cn.edu.tju.test4;public class Product {private String name;private String desc;private double price;public Product() {}public Product(String name, String desc, double price) {this.name = name;this.desc = desc;this.price = price;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDesc() {return desc;}public void setDesc(String desc) {this.desc = desc;}public double getPrice() {return price;}public void setPrice(double price) {this.price = price;}@Overridepublic String toString() {return "Product{" +"name='" + name + '\'' +", desc='" + desc + '\'' +", price=" + price +'}';}
}

三、配置ElasticsearchClient

package cn.edu.tju.config;import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration
public class ElasticsearchClientConfig {@Value("${spring.elasticsearch.uris}")private String serverAddress;@Beanpublic ElasticsearchClient getElasticsearchClient(){RestClient restClient = RestClient.builder(HttpHost.create(serverAddress)).build();ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());ElasticsearchClient esClient = new ElasticsearchClient(transport);return esClient;}
}

其中ES服务器的地址复用spring data ES 的spring.elasticsearch.uris

四、使用ElasticsearchClient操作索引

package cn.edu.tju.controller;import cn.edu.tju.test4.Product;
import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.elasticsearch.core.GetResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class EsDemoController5 {@Autowiredprivate ElasticsearchClient esClient;@RequestMapping("/test6")public String test6() throws Exception{GetResponse<Product> productGetResponse = esClient.get(g -> g.index("demo7").id("1"),Product.class);String result = productGetResponse.source().toString();return result;}
}

其中ES 7.16.2中demo7这个索引的mapping如下：

{"demo7" : {"mappings" : {"properties" : {"desc" : {"type" : "text","fields" : {"keyword" : {"type" : "keyword","ignore_above" : 256}}},"name" : {"type" : "text","fields" : {"keyword" : {"type" : "keyword","ignore_above" : 256}}},"price" : {"type" : "float"}}}}
}