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

@Test
 void 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) {
     }
   }
 }