feat: Add java sample for managed autoscaler (#2709)

Add java sample for managed autoscaler.

See the support for autoscaler here: https://togithub.com/claire921/java-spanner/pull/1/commits/e5e6923a351670ab237c411bb4a549533dac1b6b.

Author: claire921

README.md

@@ -278,6 +278,7 @@ Samples are in the [`samples/`](https://github.com/googleapis/java-spanner/tree/
 | Create Database With Version Retention Period Sample | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/CreateDatabaseWithVersionRetentionPeriodSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/CreateDatabaseWithVersionRetentionPeriodSample.java) |
 | Create Instance Config Sample | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/CreateInstanceConfigSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/CreateInstanceConfigSample.java) |
 | Create Instance Example | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/CreateInstanceExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/CreateInstanceExample.java) |
+| Create Instance With Autoscaling Config Example | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/CreateInstanceWithAutoscalingConfigExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/CreateInstanceWithAutoscalingConfigExample.java) |
 | Create Instance With Processing Units Example | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/CreateInstanceWithProcessingUnitsExample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/CreateInstanceWithProcessingUnitsExample.java) |
 | Create Sequence Sample | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/CreateSequenceSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/CreateSequenceSample.java) |
 | Create Table With Foreign Key Delete Cascade Sample | [source code](https://github.com/googleapis/java-spanner/blob/main/samples/snippets/src/main/java/com/example/spanner/CreateTableWithForeignKeyDeleteCascadeSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-spanner&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/spanner/CreateTableWithForeignKeyDeleteCascadeSample.java) |

samples/snippets/src/main/java/com/example/spanner/CreateInstanceWithAutoscalingConfigExample.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2023 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.spanner;
+
+// [START spanner_create_instance_with_autoscaling_config]
+
+import com.google.api.gax.longrunning.OperationFuture;
+import com.google.cloud.spanner.Instance;
+import com.google.cloud.spanner.InstanceAdminClient;
+import com.google.cloud.spanner.InstanceConfigId;
+import com.google.cloud.spanner.InstanceId;
+import com.google.cloud.spanner.InstanceInfo;
+import com.google.cloud.spanner.Spanner;
+import com.google.cloud.spanner.SpannerOptions;
+import com.google.spanner.admin.instance.v1.AutoscalingConfig;
+import com.google.spanner.admin.instance.v1.CreateInstanceMetadata;
+import java.util.concurrent.ExecutionException;
+
+class CreateInstanceWithAutoscalingConfigExample {
+
+  static void createInstance() {
+    // TODO(developer): Replace these variables before running the sample.
+    String projectId = "my-project";
+    String instanceId = "my-instance";
+    createInstance(projectId, instanceId);
+  }
+
+  static void createInstance(String projectId, String instanceId) {
+    Spanner spanner = SpannerOptions.newBuilder().setProjectId(projectId).build().getService();
+    InstanceAdminClient instanceAdminClient = spanner.getInstanceAdminClient();
+
+    // Set Instance configuration.
+    String configId = "regional-us-central1";
+    // Create an autoscaling config.
+    AutoscalingConfig autoscalingConfig =
+        AutoscalingConfig.newBuilder()
+            .setAutoscalingLimits(
+                AutoscalingConfig.AutoscalingLimits.newBuilder().setMinNodes(1).setMaxNodes(2))
+            .setAutoscalingTargets(
+                AutoscalingConfig.AutoscalingTargets.newBuilder()
+                    .setHighPriorityCpuUtilizationPercent(65)
+                    .setStorageUtilizationPercent(95))
+            .build();
+
+    // Create an InstanceInfo object that will be used to create the instance.
+    InstanceInfo instanceInfo =
+        InstanceInfo.newBuilder(InstanceId.of(projectId, instanceId))
+            .setInstanceConfigId(InstanceConfigId.of(projectId, configId))
+            .setAutoscalingConfig(autoscalingConfig)
+            .setDisplayName("Descriptive name")
+            .build();
+    OperationFuture<Instance, CreateInstanceMetadata> operation =
+        instanceAdminClient.createInstance(instanceInfo);
+
+    try {
+      // Wait for the createInstance operation to finish.
+      Instance instance = operation.get();
+      System.out.printf("Autoscaler instance %s was successfully created%n", instance.getId());
+    } catch (ExecutionException e) {
+      System.out.printf(
+          "Error: Creating instance %s failed with error message %s%n",
+          instanceInfo.getId(), e.getMessage());
+    } catch (InterruptedException e) {
+      System.out.println("Error: Waiting for createInstance operation to finish was interrupted");
+    } finally {
+      spanner.close();
+    }
+  }
+}
+// [END spanner_create_instance_with_autoscaling_config]

samples/snippets/src/test/java/com/example/spanner/CreateInstanceWithAutoscalingConfigSampleIT.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2023 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.spanner;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.cloud.spanner.InstanceId;
+import java.util.UUID;
+import org.junit.Test;
+
+public class CreateInstanceWithAutoscalingConfigSampleIT extends SampleTestBase {
+
+  @Test
+  public void testCreateInstanceWithAutoscalingConfig() throws Exception {
+    String instanceId = String.format("autoscaler-%s", UUID.randomUUID());
+    String out =
+        SampleRunner.runSample(
+            () -> {
+              try {
+                CreateInstanceWithAutoscalingConfigExample.createInstance(projectId, instanceId);
+              } finally {
+                spanner.getInstanceAdminClient().deleteInstance(instanceId);
+              }
+            });
+    assertThat(out)
+        .contains(String.format("Autoscaler instance %s", InstanceId.of(projectId, instanceId)));
+  }
+}