HLRC: Add ML Get Job

client/rest-high-level/src/main/java/org/elasticsearch/client/MLRequestConverters.java

@@ -20,12 +20,14 @@
 package org.elasticsearch.client;
 
 import org.apache.http.client.methods.HttpDelete;
+import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.client.methods.HttpPut;
 import org.elasticsearch.client.RequestConverters.EndpointBuilder;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.protocol.xpack.ml.CloseJobRequest;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobRequest;
+import org.elasticsearch.protocol.xpack.ml.GetJobRequest;
 import org.elasticsearch.protocol.xpack.ml.OpenJobRequest;
 import org.elasticsearch.protocol.xpack.ml.PutJobRequest;
 
@@ -50,6 +52,23 @@ static Request putJob(PutJobRequest putJobRequest) throws IOException {
         return request;
     }
 
+    static Request getJob(GetJobRequest getJobRequest) {
+        String endpoint = new EndpointBuilder()
+            .addPathPartAsIs("_xpack")
+            .addPathPartAsIs("ml")
+            .addPathPartAsIs("anomaly_detectors")
+            .addPathPart(Strings.collectionToCommaDelimitedString(getJobRequest.getJobIds()))
+            .build();
+        Request request = new Request(HttpGet.METHOD_NAME, endpoint);
+
+        RequestConverters.Params params = new RequestConverters.Params(request);
+        if (getJobRequest.isAllowNoJobs() != null) {
+            params.putParam("allow_no_jobs", Boolean.toString(getJobRequest.isAllowNoJobs()));
+        }
+
+        return request;
+    }
+
     static Request openJob(OpenJobRequest openJobRequest) throws IOException {
         String endpoint = new EndpointBuilder()
                 .addPathPartAsIs("_xpack")

client/rest-high-level/src/main/java/org/elasticsearch/client/MachineLearningClient.java

@@ -23,6 +23,8 @@
 import org.elasticsearch.protocol.xpack.ml.CloseJobResponse;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobRequest;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobResponse;
+import org.elasticsearch.protocol.xpack.ml.GetJobRequest;
+import org.elasticsearch.protocol.xpack.ml.GetJobResponse;
 import org.elasticsearch.protocol.xpack.ml.OpenJobRequest;
 import org.elasticsearch.protocol.xpack.ml.OpenJobResponse;
 import org.elasticsearch.protocol.xpack.ml.PutJobRequest;
@@ -84,6 +86,47 @@ public void putJobAsync(PutJobRequest request, RequestOptions options, ActionLis
             Collections.emptySet());
     }
 
+    /**
+     * Gets one or more Machine Learning job configuration info.
+     *
+     * <p>
+     *     For additional info
+     *     see <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ml-get-job.html"></a>
+     * </p>
+     * @param request {@link GetJobRequest} request containing a list of jobId(s) and additional options
+     * @param options  Additional request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     * @return {@link GetJobResponse} response object containing
+     * the {@link org.elasticsearch.protocol.xpack.ml.job.config.Job} objects and the number of jobs found
+     * @throws IOException when there is a serialization issue sending the request or receiving the response
+     */
+    public GetJobResponse getJob(GetJobRequest request, RequestOptions options) throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(request,
+            MLRequestConverters::getJob,
+            options,
+            GetJobResponse::fromXContent,
+            Collections.emptySet());
+    }
+
+     /**
+     * Gets one or more Machine Learning job configuration info, asynchronously.
+     *
+     * <p>
+     *     For additional info
+     *     see <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ml-get-job.html"></a>
+     * </p>
+     * @param request {@link GetJobRequest} request containing a list of jobId(s) and additional options
+     * @param options  Additional request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     * @param listener Listener to be notified with {@link GetJobResponse} upon request completion
+     */
+    public void getJobAsync(GetJobRequest request, RequestOptions options, ActionListener<GetJobResponse> listener) {
+        restHighLevelClient.performRequestAsyncAndParseEntity(request,
+            MLRequestConverters::getJob,
+            options,
+            GetJobResponse::fromXContent,
+            listener,
+            Collections.emptySet());
+    }
+
     /**
      * Deletes the given Machine Learning Job
      * <p>

client/rest-high-level/src/test/java/org/elasticsearch/client/MLRequestConvertersTests.java

@@ -20,12 +20,14 @@
 package org.elasticsearch.client;
 
 import org.apache.http.client.methods.HttpDelete;
+import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
 import org.elasticsearch.protocol.xpack.ml.CloseJobRequest;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobRequest;
+import org.elasticsearch.protocol.xpack.ml.GetJobRequest;
 import org.elasticsearch.protocol.xpack.ml.OpenJobRequest;
 import org.elasticsearch.protocol.xpack.ml.PutJobRequest;
 import org.elasticsearch.protocol.xpack.ml.job.config.AnalysisConfig;
@@ -54,6 +56,23 @@ public void testPutJob() throws IOException {
         }
     }
 
+    public void testGetJob() {
+        GetJobRequest getJobRequest = new GetJobRequest();
+
+        Request request = MLRequestConverters.getJob(getJobRequest);
+
+        assertEquals(HttpGet.METHOD_NAME, request.getMethod());
+        assertEquals("/_xpack/ml/anomaly_detectors", request.getEndpoint());
+        assertFalse(request.getParameters().containsKey("allow_no_jobs"));
+
+        getJobRequest = new GetJobRequest("job1", "jobs*");
+        getJobRequest.setAllowNoJobs(true);
+        request = MLRequestConverters.getJob(getJobRequest);
+
+        assertEquals("/_xpack/ml/anomaly_detectors/job1,jobs*", request.getEndpoint());
+        assertEquals(Boolean.toString(true), request.getParameters().get("allow_no_jobs"));
+    }
+
     public void testOpenJob() throws Exception {
         String jobId = "some-job-id";
         OpenJobRequest openJobRequest = new OpenJobRequest(jobId);

client/rest-high-level/src/test/java/org/elasticsearch/client/MachineLearningIT.java

@@ -25,6 +25,8 @@
 import org.elasticsearch.protocol.xpack.ml.CloseJobResponse;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobRequest;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobResponse;
+import org.elasticsearch.protocol.xpack.ml.GetJobRequest;
+import org.elasticsearch.protocol.xpack.ml.GetJobResponse;
 import org.elasticsearch.protocol.xpack.ml.OpenJobRequest;
 import org.elasticsearch.protocol.xpack.ml.OpenJobResponse;
 import org.elasticsearch.protocol.xpack.ml.PutJobRequest;
@@ -36,7 +38,11 @@
 
 import java.util.Arrays;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
 
+import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.Matchers.containsInAnyOrder;
+import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.is;
 
 @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/32993")
@@ -54,6 +60,41 @@ public void testPutJob() throws Exception {
         assertThat(createdJob.getJobType(), is(Job.ANOMALY_DETECTOR_JOB_TYPE));
     }
 
+    public void testGetJob() throws Exception {
+        String jobId1 = randomValidJobId();
+        String jobId2 = randomValidJobId();
+
+        Job job1 = buildJob(jobId1);
+        Job job2 = buildJob(jobId2);
+        MachineLearningClient machineLearningClient = highLevelClient().machineLearning();
+        machineLearningClient.putJob(new PutJobRequest(job1), RequestOptions.DEFAULT);
+        machineLearningClient.putJob(new PutJobRequest(job2), RequestOptions.DEFAULT);
+
+        GetJobRequest request = new GetJobRequest(jobId1, jobId2);
+
+        // Test getting specific jobs
+        GetJobResponse response = execute(request, machineLearningClient::getJob, machineLearningClient::getJobAsync);
+
+        assertEquals(2, response.getCount());
+        assertThat(response.getJobs(), hasSize(2));
+        assertThat(response.getJobs().stream().map(Job::getId).collect(Collectors.toList()), containsInAnyOrder(jobId1, jobId2));
+
+        // Test getting all jobs explicitly
+        request = GetJobRequest.getAllJobsRequest();
+        response = execute(request, machineLearningClient::getJob, machineLearningClient::getJobAsync);
+
+        assertTrue(response.getCount() >= 2L);
+        assertTrue(response.getJobs().size() >= 2L);
+        assertThat(response.getJobs().stream().map(Job::getId).collect(Collectors.toList()), hasItems(jobId1, jobId2));
+
+        // Test getting all jobs implicitly
+        response = execute(new GetJobRequest(), machineLearningClient::getJob, machineLearningClient::getJobAsync);
+
+        assertTrue(response.getCount() >= 2L);
+        assertTrue(response.getJobs().size() >= 2L);
+        assertThat(response.getJobs().stream().map(Job::getId).collect(Collectors.toList()), hasItems(jobId1, jobId2));
+    }
+
     public void testDeleteJob() throws Exception {
         String jobId = randomValidJobId();
         Job job = buildJob(jobId);

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/MlClientDocumentationIT.java

@@ -29,6 +29,8 @@
 import org.elasticsearch.protocol.xpack.ml.CloseJobResponse;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobRequest;
 import org.elasticsearch.protocol.xpack.ml.DeleteJobResponse;
+import org.elasticsearch.protocol.xpack.ml.GetJobRequest;
+import org.elasticsearch.protocol.xpack.ml.GetJobResponse;
 import org.elasticsearch.protocol.xpack.ml.OpenJobRequest;
 import org.elasticsearch.protocol.xpack.ml.OpenJobResponse;
 import org.elasticsearch.protocol.xpack.ml.PutJobRequest;
@@ -43,8 +45,11 @@
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
 
+import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.hasSize;
 
 public class MlClientDocumentationIT extends ESRestHighLevelClientTestCase {
 
@@ -126,6 +131,63 @@ public void onFailure(Exception e) {
         }
     }
 
+    public void testGetJob() throws Exception {
+        RestHighLevelClient client = highLevelClient();
+
+        String jobId = "get-machine-learning-job1";
+
+        Job job = MachineLearningIT.buildJob("get-machine-learning-job1");
+        client.machineLearning().putJob(new PutJobRequest(job), RequestOptions.DEFAULT);
+
+        Job secondJob = MachineLearningIT.buildJob("get-machine-learning-job2");
+        client.machineLearning().putJob(new PutJobRequest(secondJob), RequestOptions.DEFAULT);
+
+        {
+            //tag::x-pack-ml-get-job-request
+            GetJobRequest request = new GetJobRequest("get-machine-learning-job1", "get-machine-learning-job*"); //<1>
+            request.setAllowNoJobs(true); //<2>
+            //end::x-pack-ml-get-job-request
+
+            //tag::x-pack-ml-get-job-execute
+            GetJobResponse response = client.machineLearning().getJob(request, RequestOptions.DEFAULT);
+            long numberOfJobs = response.getCount(); //<1>
+            List<Job> jobs = response.getJobs(); //<2>
+            //end::x-pack-ml-get-job-execute
+
+            assertEquals(2, response.getCount());
+            assertThat(response.getJobs(), hasSize(2));
+            assertThat(response.getJobs().stream().map(Job::getId).collect(Collectors.toList()),
+                containsInAnyOrder(job.getId(), secondJob.getId()));
+        }
+        {
+            GetJobRequest request = new GetJobRequest("get-machine-learning-job1", "get-machine-learning-job*");
+
+            // tag::x-pack-ml-get-job-listener
+            ActionListener<GetJobResponse> listener = new ActionListener<GetJobResponse>() {
+                @Override
+                public void onResponse(GetJobResponse response) {
+                    // <1>
+                }
+
+                @Override
+                public void onFailure(Exception e) {
+                    // <2>
+                }
+            };
+            // end::x-pack-ml-get-job-listener
+
+            // Replace the empty listener by a blocking listener in test
+            final CountDownLatch latch = new CountDownLatch(1);
+            listener = new LatchedActionListener<>(listener, latch);
+
+            // tag::x-pack-ml-get-job-execute-async
+            client.machineLearning().getJobAsync(request, RequestOptions.DEFAULT, listener); // <1>
+            // end::x-pack-ml-get-job-execute-async
+
+            assertTrue(latch.await(30L, TimeUnit.SECONDS));
+        }
+    }
+
     public void testDeleteJob() throws Exception {
         RestHighLevelClient client = highLevelClient();
 

docs/java-rest/high-level/ml/get-job.asciidoc

@@ -0,0 +1,57 @@
+[[java-rest-high-x-pack-ml-get-job]]
+=== Get Job API
+
+The Get Job API provides the ability to get {ml} jobs in the cluster.
+It accepts a `GetJobRequest` object and responds
+with a `GetJobResponse` object.
+
+[[java-rest-high-x-pack-ml-get-job-request]]
+==== Get Job Request
+
+A `GetJobRequest` object gets can have any number of `jobId` or `groupName`
+entries. However, they all must be non-null. An empty list is the same as
+requesting for all jobs.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MlClientDocumentationIT.java[x-pack-ml-get-job-request]
+--------------------------------------------------
+<1> Constructing a new request referencing existing `jobIds`, can contain wildcards
+<2> Whether to ignore if a wildcard expression matches no jobs.
+ (This includes `_all` string or when no jobs have been specified)
+
+[[java-rest-high-x-pack-ml-get-job-execution]]
+==== Execution
+
+The request can be executed through the `MachineLearningClient` contained
+in the `RestHighLevelClient` object, accessed via the `machineLearningClient()` method.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MlClientDocumentationIT.java[x-pack-ml-get-job-execute]
+--------------------------------------------------
+<1> `getCount()` from the `GetJobResponse` indicates the number of jobs found
+<2> `getJobs()` is the collection of {ml} `Job` objects found
+
+[[java-rest-high-x-pack-ml-get-job-execution-async]]
+==== Asynchronous Execution
+
+The request can also be executed asynchronously:
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MlClientDocumentationIT.java[x-pack-ml-get-job-execute-async]
+--------------------------------------------------
+<1> The `GetJobRequest` to execute and the `ActionListener` to use when
+the execution completes
+
+The method does not block and returns immediately. The passed `ActionListener` is used
+to notify the caller of completion. A typical `ActionListener` for `GetJobResponse` may
+look like
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests}/MlClientDocumentationIT.java[x-pack-ml-get-job-listener]
+--------------------------------------------------
+<1> `onResponse` is called back when the action is completed successfully
+<2> `onFailure` is called back when some unexpected error occurs

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

@@ -205,11 +205,13 @@ include::licensing/delete-license.asciidoc[]
 The Java High Level REST Client supports the following Machine Learning APIs:
 
 * <<java-rest-high-x-pack-ml-put-job>>
+* <<java-rest-high-x-pack-ml-get-job>>
 * <<java-rest-high-x-pack-ml-delete-job>>
 * <<java-rest-high-x-pack-ml-open-job>>
 * <<java-rest-high-x-pack-ml-close-job>>
 
 include::ml/put-job.asciidoc[]
+include::ml/get-job.asciidoc[]
 include::ml/delete-job.asciidoc[]
 include::ml/open-job.asciidoc[]
 include::ml/close-job.asciidoc[]