BS问题，elasticsearch 8.5.2 建立索引的时候报错 Connection is closed

环境：jdk11 

elasticsearch版本:8.5.2

spring boot版本：2.3.12.RELEASE

官网给的依赖 

<dependency>
      <groupId>co.elastic.clients</groupId>
      <artifactId>elasticsearch-java</artifactId>
      <version>8.5.1</version>
    </dependency>
 
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.12.3</version>
    </dependency>

window 11 安装的elasticsearch

今天在调试elasticsearch的时候，按照官网的步骤

1、先获取 ElasticsearchClient

2、第一个示例

 这么简单的步骤居然报错了

看了一下控制台日志内容

 received plaintext http traffic on an https channel

 注意到https,好像哪里见到过

按照官网的意思：需要配置安全的https访问才行

To connect to the Elasticsearch cluster you’ll need to configure the Java API Client to use HTTPS with the generated CA certificate in order to make requests successfully.

启动elasticsearch的时候有日志输出，我的不是第一次启动了，所以日志里面没有，我的办法是删除elasticsearch项目文件夹，重新解压压缩文件（elasticsearch-8.5.2-windows-x86_64），然后再启动，获取日志信息

-> Elasticsearch security features have been automatically configured!
-> Authentication is enabled and cluster connections are encrypted.
 
->  Password for the elastic user (reset with `bin/elasticsearch-reset-password -u elastic`):
  lhQpLELkjkrawaBoaz0Q
 
->  HTTP CA certificate SHA-256 fingerprint:
  a52dd93511e8c6045e21f16654b77c9ee0f34aea26d9f40320b531c474676228
...

使用安全的认证的 ElasticsearchClient 

String fingerprint = "<certificate fingerprint>";
 
SSLContext sslContext = TransportUtils
    .sslContextFromCaFingerprint(fingerprint); 
 
BasicCredentialsProvider credsProv = new BasicCredentialsProvider(); 
credsProv.setCredentials(
    AuthScope.ANY, new UsernamePasswordCredentials(login, password)
);
 
RestClient restClient = RestClient
    .builder(new HttpHost(host, port, "https")) 
    .setHttpClientConfigCallback(hc -> hc
        .setSSLContext(sslContext) 
        .setDefaultCredentialsProvider(credsProv)
    )
    .build();
 
// Create the transport and the API client
ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
ElasticsearchClient client = new ElasticsearchClient(transport);

 然后就可以正常创建索引了

总结：有时候想简单的经历一些事情，在没有完全了解的情况下动手，容易掉坑里