docs: add get operation code snippet (#28)

* docs: add get operation code snippet

* add batch import

* fix int

* fix lint

* fix import

* rename method

* add operation import

* fix symbol

* add multiline

* 🦉 Updates from OwlBot post-processor

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Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: changsongd

README.md

@@ -80,6 +80,7 @@ Samples are in the [`samples/`](https://github.com/googleapis/java-optimization/
 | Sample                      | Source Code                       | Try it |
 | --------------------------- | --------------------------------- | ------ |
 | Async Api | [source code](https://github.com/googleapis/java-optimization/blob/main/samples/snippets/src/main/java/com/example/optimizationai/AsyncApi.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-optimization&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/optimizationai/AsyncApi.java) |
+| Get Operation | [source code](https://github.com/googleapis/java-optimization/blob/main/samples/snippets/src/main/java/com/example/optimizationai/GetOperation.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-optimization&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/optimizationai/GetOperation.java) |
 | Sync Api | [source code](https://github.com/googleapis/java-optimization/blob/main/samples/snippets/src/main/java/com/example/optimizationai/SyncApi.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-optimization&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/optimizationai/SyncApi.java) |
 | Sync Api With Long Timeout | [source code](https://github.com/googleapis/java-optimization/blob/main/samples/snippets/src/main/java/com/example/optimizationai/SyncApiWithLongTimeout.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-optimization&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/optimizationai/SyncApiWithLongTimeout.java) |
 

samples/snippets/src/main/java/com/example/optimizationai/GetOperation.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.optimizationai;
+
+// [START cloudoptimization_get_operation]
+import com.google.cloud.optimization.v1.FleetRoutingClient;
+import com.google.longrunning.Operation;
+import java.io.IOException;
+
+class GetOperation {
+
+  static void getOperation() throws IOException {
+    // TODO(developer): Replace these variables before running the sample.
+    String operationFullId = "projects/[projectId]/operations/[operationId]";
+    getOperation(operationFullId);
+  }
+
+  // Get the status of an operation
+  static void getOperation(String operationFullId) throws IOException {
+    // Initialize client that will be used to send requests. This client only needs to be created
+    // once, and can be reused for multiple requests. After completing all of your requests, call
+    // the "close" method on the client to safely clean up any remaining background resources.
+    try (FleetRoutingClient client = FleetRoutingClient.create()) {
+      // Get the latest state of a long-running operation.
+      Operation operation = client.getOperationsClient().getOperation(operationFullId);
+
+      // Display operation details.
+      System.out.println("Operation details:");
+      System.out.format("\tName: %s\n", operation.getName());
+      System.out.format("\tMetadata Type Url: %s\n", operation.getMetadata().getTypeUrl());
+      System.out.format("\tDone: %s\n", operation.getDone());
+      if (operation.hasResponse()) {
+        System.out.format("\tResponse Type Url: %s\n", operation.getResponse().getTypeUrl());
+      }
+      if (operation.hasError()) {
+        System.out.println("\tResponse:");
+        System.out.format("\t\tError code: %s\n", operation.getError().getCode());
+        System.out.format("\t\tError message: %s\n", operation.getError().getMessage());
+      }
+    }
+  }
+}
+// [END cloudoptimization_get_operation]

samples/snippets/src/test/java/com/example/optimizationai/GetOperationTest.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.optimizationai;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.api.gax.longrunning.OperationFuture;
+import com.google.cloud.optimization.v1.AsyncModelMetadata;
+import com.google.cloud.optimization.v1.BatchOptimizeToursRequest;
+import com.google.cloud.optimization.v1.BatchOptimizeToursResponse;
+import com.google.cloud.optimization.v1.FleetRoutingClient;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+/** Tests for GetOperation sample. */
+public class GetOperationTest {
+  private static final String PROJECT_ID = System.getenv("GOOGLE_CLOUD_PROJECT");
+  private static final String PROJECT_PARENT = String.format("projects/%s", PROJECT_ID);
+
+  private ByteArrayOutputStream bout;
+  private PrintStream out;
+  private PrintStream originalPrintStream;
+
+  @Before
+  public void setUp() {
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    originalPrintStream = System.out;
+    System.setOut(out);
+  }
+
+  @After
+  public void tearDown() {
+    System.out.flush();
+    System.setOut(originalPrintStream);
+  }
+
+  @Test
+  public void testSyncApi() throws Exception {
+    FleetRoutingClient fleetRoutingClient = FleetRoutingClient.create();
+    BatchOptimizeToursRequest request =
+        BatchOptimizeToursRequest.newBuilder().setParent(PROJECT_PARENT).build();
+    OperationFuture<BatchOptimizeToursResponse, AsyncModelMetadata> response =
+        fleetRoutingClient.batchOptimizeToursAsync(request);
+
+    GetOperation.getOperation(response.getInitialFuture().get().getName());
+    String got = bout.toString();
+    assertThat(got).contains("operations");
+  }
+}