<dependency>
  <groupId>org.elasticsearch</groupId>
  <artifactId>elasticsearch-core</artifactId>
  <version>6.8.1</version>
</dependency>

implementation 'org.elasticsearch:elasticsearch-core:6.8.1'

implementation("org.elasticsearch:elasticsearch-core:6.8.1")

libraryDependencies += "org.elasticsearch" % "elasticsearch-core" % "6.8.1"

@Grapes(
  @Grab(group='org.elasticsearch', module='elasticsearch-core', version='6.8.1')
)

<dependency org="org.elasticsearch" name="elasticsearch-core" rev="6.8.1" />

[org.elasticsearch/elasticsearch-core "6.8.1"]

'org.elasticsearch:elasticsearch-core:jar:6.8.1'