[ML-Dataframe] Add Data Frame client to the Java HLRC (#39921)

Adds DataFrameClient to the Java HLRC and implements PUT and 
DELETE data frame transform.

docs/java-rest/high-level/dataframe/delete_data_frame.asciidoc

@@ -0,0 +1,25 @@
+--
+:api: delete-data-frame-transform
+:request: DeleteDataFrameTransformRequest
+:response: AcknowledgedResponse
+--
+[id="{upid}-{api}"]
+=== Delete Data Frame Transform API
+
+[id="{upid}-{api}-request"]
+==== Delete Data Frame Transform Request
+
+A +{request}+ object requires a non-null `id`.
+
+["source","java",subs="attributes,callouts,macros"]
+---------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-request]
+---------------------------------------------------
+<1> Constructing a new request referencing an existing {dataframe-transform}
+
+include::../execution.asciidoc[]
+
+[id="{upid}-{api}-response"]
+==== Response
+
+The returned +{response}+ object acknowledges the Data Frame Transform deletion.

docs/java-rest/high-level/dataframe/put_data_frame.asciidoc

@@ -0,0 +1,93 @@
+--
+:api: put-data-frame-transform
+:request: PutDataFrameTransformRequest
+:response: AcknowledgedResponse
+--
+[id="{upid}-{api}"]
+=== Put Data Frame Transform API
+
+The Put Data Frame Transform API is used to create a new {dataframe-transform}.
+
+The API accepts a +{request}+ object as a request and returns a +{response}+.
+
+[id="{upid}-{api}-request"]
+==== Put Data Frame Request
+
+A +{request}+ requires the following argument:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-request]
+--------------------------------------------------
+<1> The configuration of the {dataframe-job} to create
+
+[id="{upid}-{api}-config"]
+==== Data Frame Transform Configuration
+
+The `DataFrameTransformConfig` object contains all the details about the {dataframe-transform}
+configuration and contains the following arguments:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-config]
+--------------------------------------------------
+<1> The {dataframe-transform} ID
+<2> The source index or index pattern
+<3> The destination index
+<4> Optionally a QueryConfig
+<5> The PivotConfig
+
+[id="{upid}-{api}-query-config"]
+==== QueryConfig
+
+The query with which to select data from the source.
+If not set a `match_all` query is used by default.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-query-config]
+--------------------------------------------------
+
+==== PivotConfig
+
+Defines the pivot function `group by` fields and the aggregation to reduce the data.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-pivot-config]
+--------------------------------------------------
+
+===== GroupConfig
+The grouping terms. Defines the group by and destination fields
+which are produced by the pivot function. There are 3 types of
+groups
+
+* Terms
+* Histogram
+* Date Histogram
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-group-config]
+--------------------------------------------------
+<1> The destination field
+<2> Group by values of the `user_id` field
+
+===== AggregationConfig
+
+Defines the aggregations for the group fields.
+// TODO link to the supported aggregations
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-agg-config]
+--------------------------------------------------
+<1> Aggregate the average star rating
+
+include::../execution.asciidoc[]
+
+[id="{upid}-{api}-response"]
+==== Response
+
+The returned +{response}+ acknowledges the successful creation of
+the new {dataframe-transform} or an error if the configuration is invalid.

docs/java-rest/high-level/supported-apis.asciidoc

@@ -550,3 +550,16 @@ include::ilm/stop_lifecycle_management.asciidoc[]
 include::ilm/lifecycle_management_status.asciidoc[]
 include::ilm/retry_lifecycle_policy.asciidoc[]
 include::ilm/remove_lifecycle_policy_from_index.asciidoc[]
+
+== Data Frame APIs
+
+:upid: {mainid}-dataframe
+:doc-tests-file: {doc-tests}/DataFrameTransformDocumentationIT.java
+
+The Java High Level REST Client supports the following Data Frame APIs:
+
+* <<{upid}-put-data-frame-transform>>
+* <<{upid}-delete-data-frame-transform>>
+
+include::dataframe/put_data_frame.asciidoc[]
+include::dataframe/delete_data_frame.asciidoc[]