elasticsearch-7.x용 java connect client: RestHighLevelClient를 이용 public class ElasticConnect { private static Logger log = LoggerFactory.getLogger(ElasticConnect.class); private static RestHighLevelClient client = null; public static synchronized RestHighLevelClient getClient() { if( !isValidConnection()){ // 아이피1:9200;아이피2:9200 String nodes = "설정파일에서 읽어들인 값"; // elastic에 user/passwd 가 설정되어 있어야 함..