1）TCP 

        spring-data-elasticsearch:transport-api.jar；

        springboot版本不同，transport-api.jar不同，不能适配es版本, 7.x已经不建议使用，8以后就要废弃 

2）、9200：HTTP

         JestClient：非官方，更新慢

         RestTemplate：模拟发HTTP请求，ES很多操作需要自己封装，麻烦

         HttpClient：同上

         Elasticsearch-Rest-Client：官方RestClient，封装了ES操作，API层次分明，上手简单

        最终选择Elasticsearch-Rest-Client（elasticsearch-rest-high-level-client） https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high.html

1、SpringBoot整合

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

2、配置

@Bean RestHighLevelClientclient(){ RestClientBuilder builder = RestClient.builder(newHttpHost("192.168.56.10", 9200, "http")); return new RestHighLevelClient(builder); 
}

3、使用 参照官方文档

@Testvoid test1() throwsIOException{Product product=new Product();product.setSpuName("华为");product.setId(10L);IndexRequest request=new IndexRequest("product").id("20").source("spuName","华为","id",20L);
try{IndexResponse response=client.index(request,RequestOptions.DEFAULT);System.out.println(request.toString());IndexResponse response2 = client.index(request, RequestOptions.DEFAULT);} catch (ElasticsearchException e) {if (e.status() == RestStatus.CONFLICT) {}}}