docs(samples): add get transferconfig info (#300)

* docs(samples): add get transferconfig info

* docs(samples): address feedback

Author: Praful Makani

samples/snippets/src/main/java/com/example/bigquerydatatransfer/GetTransferConfigInfo.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2020 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.bigquerydatatransfer;
+
+// [START bigquerydatatransfer_get_config_info]
+import com.google.api.gax.rpc.ApiException;
+import com.google.cloud.bigquery.datatransfer.v1.DataTransferServiceClient;
+import com.google.cloud.bigquery.datatransfer.v1.GetTransferConfigRequest;
+import com.google.cloud.bigquery.datatransfer.v1.TransferConfig;
+import java.io.IOException;
+
+// Sample to get config info.
+public class GetTransferConfigInfo {
+
+  public static void main(String[] args) throws IOException {
+    // TODO(developer): Replace these variables before running the sample.
+    String configId = "MY_CONFIG_ID";
+    // i.e projects/{project_id}/transferConfigs/{config_id}` or
+    // `projects/{project_id}/locations/{location_id}/transferConfigs/{config_id}`
+    getTransferConfigInfo(configId);
+  }
+
+  public static void getTransferConfigInfo(String configId) throws IOException {
+    try (DataTransferServiceClient dataTransferServiceClient = DataTransferServiceClient.create()) {
+      GetTransferConfigRequest request =
+          GetTransferConfigRequest.newBuilder().setName(configId).build();
+      TransferConfig info = dataTransferServiceClient.getTransferConfig(request);
+      System.out.printf("\nConfig info retrieved successfully.name : %s \n", info.getName());
+    } catch (ApiException ex) {
+      System.out.print("config not found." + ex.toString());
+    }
+  }
+}
+// [END bigquerydatatransfer_get_config_info]

samples/snippets/src/test/java/com/example/bigquerydatatransfer/GetTransferConfigInfoIT.java

@@ -0,0 +1,122 @@
+/*
+ * Copyright 2020 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.bigquerydatatransfer;
+
+import static com.google.common.truth.Truth.assertThat;
+import static junit.framework.TestCase.assertNotNull;
+
+import com.google.cloud.bigquery.BigQuery;
+import com.google.cloud.bigquery.BigQueryOptions;
+import com.google.cloud.bigquery.DatasetInfo;
+import com.google.cloud.bigquery.datatransfer.v1.TransferConfig;
+import com.google.protobuf.Struct;
+import com.google.protobuf.Value;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class GetTransferConfigInfoIT {
+
+  private BigQuery bigquery;
+  private ByteArrayOutputStream bout;
+  private String name;
+  private String displayName;
+  private String datasetName;
+  private PrintStream out;
+  private PrintStream originalPrintStream;
+
+  private static final String PROJECT_ID = requireEnvVar("GOOGLE_CLOUD_PROJECT");
+
+  private static String requireEnvVar(String varName) {
+    String value = System.getenv(varName);
+    assertNotNull(
+        "Environment variable " + varName + " is required to perform these tests.",
+        System.getenv(varName));
+    return value;
+  }
+
+  @BeforeClass
+  public static void checkRequirements() {
+    requireEnvVar("GOOGLE_CLOUD_PROJECT");
+  }
+
+  @Before
+  public void setUp() {
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    originalPrintStream = System.out;
+    System.setOut(out);
+
+    displayName = "MY_SCHEDULE_NAME_TEST_" + UUID.randomUUID().toString().substring(0, 8);
+    datasetName = "MY_DATASET_NAME_TEST_" + UUID.randomUUID().toString().substring(0, 8);
+
+    // create a temporary dataset
+    bigquery = BigQueryOptions.getDefaultInstance().getService();
+    bigquery.create(DatasetInfo.of(datasetName));
+
+    // create a scheduled query
+    String query =
+        "SELECT CURRENT_TIMESTAMP() as current_time, @run_time as intended_run_time, "
+            + "@run_date as intended_run_date, 17 as some_integer";
+    String destinationTableName =
+        "MY_DESTINATION_TABLE_" + UUID.randomUUID().toString().substring(0, 8) + "_{run_date}";
+    Map<String, Value> params = new HashMap<>();
+    params.put("query", Value.newBuilder().setStringValue(query).build());
+    params.put(
+        "destination_table_name_template",
+        Value.newBuilder().setStringValue(destinationTableName).build());
+    params.put("write_disposition", Value.newBuilder().setStringValue("WRITE_TRUNCATE").build());
+    params.put("partitioning_field", Value.newBuilder().setStringValue("").build());
+    TransferConfig transferConfig =
+        TransferConfig.newBuilder()
+            .setDestinationDatasetId(datasetName)
+            .setDisplayName(displayName)
+            .setDataSourceId("scheduled_query")
+            .setParams(Struct.newBuilder().putAllFields(params).build())
+            .setSchedule("every 24 hours")
+            .build();
+    CreateScheduledQuery.createScheduledQuery(PROJECT_ID, transferConfig);
+    String result = bout.toString();
+    name = result.substring(result.indexOf(".") + 1);
+  }
+
+  @After
+  public void tearDown() {
+    // delete scheduled query that was just created
+    DeleteScheduledQuery.deleteScheduledQuery(name);
+    // delete a temporary dataset
+    bigquery.delete(datasetName, BigQuery.DatasetDeleteOption.deleteContents());
+
+    // restores print statements in the original method
+    System.setOut(originalPrintStream);
+    String output = new String(bout.toByteArray());
+    System.out.println(output);
+  }
+
+  @Test
+  public void testGetTransferConfigInfo() throws IOException {
+    GetTransferConfigInfo.getTransferConfigInfo(name);
+    assertThat(bout.toString()).contains("Config info retrieved successfully.");
+  }
+}