elasticsearch-8.x 새로운 Java Api Client: ElasticSearchClient

elasticsearch-8.x용 java api client:  https 및 계정 인증을 이용한 ElasticSearchClient

public class ElasticClient {
	private static Logger log = LoggerFactory.getLogger(ElasticClient.class);

	private static ElasticsearchClient client = null;
	private static ElasticsearchTransport transport = null;
	
	public static synchronized ElasticsearchClient getInstacne() {
		if(client == null) {
			// 아이피1:9200;아이피2:9200
			String nodes = "설정파일에서 읽어들인 값";

			// elastic에 user/passwd 가 설정되어 있어야 함
			// user/passwd설정: bin/elasticsearch-users useradd 아이디 -p 비번 -r superuser
			String user = "설정파일에서 읽어들인 값";
			String passwd = "설정파일에서 읽어들인 값";
			
			// https 여부
			boolean isSsl = true;

			new ElasticClient().initConnect(nodes, user, passwd, isSsl);
		}	
		
		return client;
	}
	
	private void initConnect(String nodes, String user, String passwd, boolean isSsl) {
		try {
			RestClientBuilder builder = null;

			String[] clients = StringUtils.split(nodes, ";");
			HttpHost[] httpHosts = new HttpHost[clients.length];

			for(int i=0; i<clients.length; i++){
				String[] clienthost = StringUtils.split(clients[i], ":");
				if(clienthost.length > 1){
					String host = clienthost[0];
					int port = ImStringUtil.parseInt(clienthost[1]);
					//System.out.println(host + " : " + port);
					if(isSsl) {
						httpHosts[i] = new HttpHost(host, port, "https");
					} else {
						httpHosts[i] = new HttpHost(host, port, "http");
					}
				}
			}

			if(StringUtils.isNotEmpty(user) && StringUtils.isNotEmpty(passwd)) {
				CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
				credentialsProvider.setCredentials(AuthScope.ANY,
						new UsernamePasswordCredentials(user, passwd));

				if(isSsl) {
					// FakeX509TrustManager implements X509TrustManager
					TrustManager[] trustManagers = new TrustManager[] { new FakeX509TrustManager() };
					
					SSLContext sslContext = SSLContext.getInstance("TLS");
					sslContext.init(null, trustManagers, new java.security.SecureRandom());

					builder = RestClient.builder(httpHosts)
							.setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
								@Override
								public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
									return httpClientBuilder
										.setSSLContext(sslContext)
										.setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE)
										.setDefaultCredentialsProvider(credentialsProvider);
								}
							});
				} else {
					builder = RestClient.builder(httpHosts)
							.setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
								@Override
								public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
									return httpClientBuilder
										.setDefaultCredentialsProvider(credentialsProvider);
								}
							});
				}
			} else {
				builder = RestClient.builder(httpHosts);
			}
			
			// Create the low-level client
			RestClient restClient = builder.build();

			// Create the transport with a Jackson mapper
			transport = new RestClientTransport(restClient, new JacksonJsonpMapper());

			// And create the API client
			client = new ElasticsearchClient(transport);

		}catch(Exception e) {
			ElasticClient.close();
			log.error("innitConnect error: {}", e);
		}
	}
	
	public static void close() {
		// Must close the transport
		try { if(transport != null) transport.close(); }catch(Exception e) {}
		try { if(client != null) client.shutdown(); }catch(Exception e) {}
	}


	/** Connect Test **/
	public static void main(String[] args) {
		ElasticsearchClient client = ElasticClient.getInstacne();			
		try {
			System.out.println("connected");
			Thread.sleep(10000);
			System.out.println("bye~~");			
		} catch(Exception e) {
			e.printStackTrace();
		} finally {
			ElasticClient.close();
		}
	}

}