Adding snippets for Spanner DatabaseAdminClient.

Author: snehashah16

google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/DatabaseAdminClientSnippets.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright 2017 Google Inc. All Rights Reserved.
+ *
+ * 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.google.cloud.examples.spanner.snippets;
+
+import com.google.api.gax.paging.Page;
+import com.google.cloud.spanner.Options.ListOption;
+import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
+import com.google.spanner.admin.database.v1.UpdateDatabaseDdlMetadata;
+import java.util.List;
+import javax.annotation.Nullable;
+
+/**
+ * This class contains snippets for {@link DatabaseAdminClient} interface.
+ */
+public interface DatabaseAdminClientSnippets {
+  
+  private final DatabaseAdminClient dbAdminClient;
+
+  public DatabaseAdminClientSnippets(DatabaseAdminClient dbAdminClient) {
+    this.dbAdminClient = dbAdminClient;
+  }
+  
+  /**
+   * Example to create database.
+   */
+  // [TARGET createDatabase(String, String, Iterable)]
+  // [VARIABLE my_instance_id]
+  // [VARIABLE my_database_id]
+  public void createDatabase(String instanceId, String databaseId) {
+    // [START createDatabase]
+    Operation<Database, CreateDatabaseMetadata> op = dbAdminClient
+        .createDatabase(
+            instanceId,
+            databaseId,
+            Arrays.asList(
+                "CREATE TABLE Singers (\n"
+                    + "  SingerId   INT64 NOT NULL,\n"
+                    + "  FirstName  STRING(1024),\n"
+                    + "  LastName   STRING(1024),\n"
+                    + "  SingerInfo BYTES(MAX)\n"
+                    + ") PRIMARY KEY (SingerId)",
+                "CREATE TABLE Albums (\n"
+                    + "  SingerId     INT64 NOT NULL,\n"
+                    + "  AlbumId      INT64 NOT NULL,\n"
+                    + "  AlbumTitle   STRING(MAX)\n"
+                    + ") PRIMARY KEY (SingerId, AlbumId),\n"
+                    + "  INTERLEAVE IN PARENT Singers ON DELETE CASCADE"));
+    Database db = op.waitFor().getResult();
+    System.out.println("Created database [" + db.getId() + "]");
+    // [END createDatabase]
+  }
+
+  /**
+   * Example to getDatabase.
+   */
+  // [TARGET getDatabase(String, String)]
+  // [VARIABLE my_instance_id]
+  // [VARIABLE my_database_id]
+  public void getDatabase(String instanceId, String databaseId) {
+    // [START getDatabase]
+    Database db = dbClient.getDatabase(instanceId, databaseId);
+    System.out.println("Fetched database [" + db.getId() + "]");
+    // [END getDatabase]
+  }
+
+  /**
+   * Example to update the database DDL.
+   */
+  // [TARGET updateDatabaseDdl(String, String, Iterable, String)]
+  // [VARIABLE my_instance_id]
+  // [VARIABLE my_database_id]
+  public void updateDatabaseDdl(String instanceId, String databaseId) {
+    // [START updateDatabaseDdl]
+    dbAdminClient.updateDatabaseDdl(instanceId, 
+        databaseId, 
+        Arrays.asList("ALTER TABLE Albums ADD COLUMN MarketingBudget INT64"), 
+        null).waitFor();
+    System.out.println("UpdateDatabaseDdl: added MarketingBudget column");
+    // [END updateDatabaseDdl]
+  }
+
+  /** 
+   * Example to drop a Cloud Spanner database. 
+   */
+  // [TARGET dropDatabase(String, String)]
+  // [VARIABLE my_instance_id]
+  // [VARIABLE my_database_id]
+  public void dropDatabase(String instanceId, String databaseId) {
+    // [START dropDatabase]
+    dbAdminClient.dropDatabase(instanceId, databaseId);
+    System.out.println("DropDatabase: " + databaseId);
+    // [END dropDatabase]
+  }
+
+  /**
+   * Example to get the schema of a Cloud Spanner database.
+   */
+  // [TARGET getDatabaseDdl(instanceId, databaseId)]
+  // [VARIABLE my_instance_id]
+  // [VARIABLE my_database_id]
+  public void getDatabaseDdl(String instanceId, String databaseId) {
+    // [START getDatabaseDdl]
+    List<String> statementsInDb = dbAdminClient.getDatabaseDdl(instanceId, databaseId);
+    // [END getDatabaseDdl]
+  }
+
+  /** 
+   * Example to get the list of Cloud Spanner database in the given instance. 
+   */
+  // [TARGET listDatabases(String, ListOption)]
+  // [VARIABLE my_instance_id]
+  public void listDatabases(String instanceId) {
+    // [START listDatabases]
+    Page<Database> page = dbAdminClient.listDatabases(instanceId, Options.pageSize(1));
+    while (page != null) {
+      Database db = Iterables.getOnlyElement(page.getValues());
+      System.out.println(db.getId().getDatabase());
+      page = page.getNextPage();
+    }
+    // [END listDatabases]
+  }
+}