1.安装依赖（注意版本要和自己安装的es版本对应）

<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.4.2</version>
</dependency>

         打开发现部分依赖和我们es版本不一致，是因为springboot指定了版本，我们需要更换为自己对应版本。

1.1、改为自己es对应版本

<elasticsearch.version>7.4.2</elasticsearch.version>

 2.编写配置类

@Configuration
public class GullmallElasticSearchConfig {

    @Bean
    public RestHighLevelClient esRestClient() {
        RestClientBuilder builder = null;
        builder = RestClient.builder(new HttpHost("192.168.56.10",9200,"http"));
        RestHighLevelClient client = new RestHighLevelClient(builder);
        return client;
    }
}

3.配置类添加请求选项

    public static final RequestOptions COMMON_OPTIONS;
    static {
        RequestOptions.Builder builder = RequestOptions.DEFAULT.toBuilder();
//        builder.addHeader("Authorization", "Bearer " + TOKEN);
//        builder.setHttpAsyncResponseConsumerFactory(
//                new HttpAsyncResponseConsumerFactory
//                        .HeapBufferedResponseConsumerFactory(30 * 1024 * 1024 * 1024));
        COMMON_OPTIONS = builder.build();
    }

4、测试

4.1、存储数据到es

package com.atguigu.gulimall.search;

import com.alibaba.fastjson.JSON;
import com.atguigu.gulimall.search.config.GullmallElasticSearchConfig;
import lombok.Data;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;

/**
 * @author cy
 * @create 2022-11-04 12:03
 */
@SpringBootTest
public class GulimallSearchApplicationTests {

    @Autowired
    private RestHighLevelClient client;


    /**
     * 测试存储数据到es（更新也可以）
     * @throws IOException
     */
    @Test
    public void indexData() throws IOException {
        IndexRequest indexRequest = new IndexRequest("users");
        indexRequest.id("1");
//        indexRequest.source("userName","zhangsan","age",18,"gender","男");
        User user = new User();
        user.setName("张三");
        user.setGender("男");
        user.setAge(18);
        String jsonString = JSON.toJSONString(user);
        indexRequest.source(jsonString, XContentType.JSON);//要保存的内容

        //执行操作
        IndexResponse index = client.index(indexRequest, GullmallElasticSearchConfig.COMMON_OPTIONS);

        System.out.println(index);
    }

    @Data
    class User {
        private String Name;
        private String gender;
        private Integer age;
    }

}

 4.2、检索数据

         使用Kibana工具检索

GET bank/_search
{
	"query": {
		"match": {
			"address": {
				"query": "mill"
			}
		}
	},
	"aggregations": {
		"ageAgg": {
			"terms": {
				"field": "age",
				"size": 10,	
			}
		},
		"balanceAvg": {
			"avg": {
				"field": "balance"
			}
		}
	}
}

        代码实现 ：

package com.atguigu.gulimall.search;

import com.alibaba.fastjson.JSON;
import com.atguigu.gulimall.search.config.GullmallElasticSearchConfig;
import com.mysql.cj.QueryBindings;
import lombok.Data;
import lombok.ToString;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.Aggregation;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.aggregations.metrics.Avg;
import org.elasticsearch.search.aggregations.metrics.AvgAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.naming.directory.SearchResult;
import java.io.IOException;

/**
 * @author cy
 * @create 2022-11-04 12:03
 */
@SpringBootTest
public class GulimallSearchApplicationTests {

    @Autowired
    private RestHighLevelClient client;

    @ToString
    @Data
    static class Account {

        private int account_number;

        private int balance;

        private String firstname;

        private String lastname;

        private int age;

        private String gender;

        private String address;

        private String employer;

        private String email;

        private String city;

        private String state;
    }

    @Test
    public void searchData() throws IOException {
        //1、创建构建索引
        SearchRequest searchRequest = new SearchRequest();
        //1、指定索引
        searchRequest.indices("bank");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //1.1、构造检索条件
        sourceBuilder.query(QueryBuilders.matchQuery("address","mill"));

        //1.2、按照年龄的值分布进行聚合
        TermsAggregationBuilder ageAgg = AggregationBuilders.terms("ageAgg").field("age").size(10);
        sourceBuilder.aggregation(ageAgg);

        //1.3、计算平均薪资
        AvgAggregationBuilder balanceAvg = AggregationBuilders.avg("balanceAvg").field("balance");
        sourceBuilder.aggregation(balanceAvg);

        System.out.println("检索条件"+sourceBuilder.toString());
        searchRequest.source(sourceBuilder);

        //2、执行检索
        SearchResponse searchResponse = client.search(searchRequest, GullmallElasticSearchConfig.COMMON_OPTIONS);

        //3、分析结果
        System.out.println(searchResponse.toString());

        //3.1)、获取所有查到的数据
        SearchHits hits = searchResponse.getHits();
        SearchHit[] searchHits = hits.getHits();
        for (SearchHit hit : searchHits) {
            String string = hit.getSourceAsString();
            Account account = JSON.parseObject(string, Account.class);
            System.out.println("account"+account);
        }

        //3.2、获取这次检索到的分析信息
        Aggregations aggregations = searchResponse.getAggregations();
        Terms ageAgg1 = aggregations.get("ageAgg");
        for (Terms.Bucket bucket : ageAgg1.getBuckets()) {
            String keyAsString = bucket.getKeyAsString();
            System.out.println("年龄："+keyAsString + "==>" +bucket.getDocCount());
        }

        Avg balanceAvg1 = aggregations.get("balanceAvg");
        System.out.println("平均薪资："+balanceAvg1.getValue());
    }

}

         结果：