docs(samples): add get connection (#156)

Author: Praful Makani

samples/snippets/src/main/java/com/example/bigqueryconnection/GetConnection.java

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+/*
+ * 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.bigqueryconnection;
+
+// [START bigqueryconnection_get_connection]
+import com.google.cloud.bigquery.connection.v1.Connection;
+import com.google.cloud.bigquery.connection.v1.ConnectionName;
+import com.google.cloud.bigquery.connection.v1.GetConnectionRequest;
+import com.google.cloud.bigqueryconnection.v1.ConnectionServiceClient;
+import java.io.IOException;
+
+// Sample to get connection
+public class GetConnection {
+
+  public static void main(String[] args) throws IOException {
+    // TODO(developer): Replace these variables before running the sample.
+    String projectId = "MY_PROJECT_ID";
+    String location = "MY_LOCATION";
+    String connectionId = "MY_CONNECTION_ID";
+    getConnection(projectId, location, connectionId);
+  }
+
+  public static void getConnection(String projectId, String location, String connectionId)
+      throws IOException {
+    try (ConnectionServiceClient client = ConnectionServiceClient.create()) {
+      ConnectionName name = ConnectionName.of(projectId, location, connectionId);
+      GetConnectionRequest request =
+          GetConnectionRequest.newBuilder().setName(name.toString()).build();
+      Connection response = client.getConnection(request);
+      System.out.println("Connection info retrieved successfully :" + response.getName());
+    }
+  }
+}
+// [END bigqueryconnection_get_connection]

samples/snippets/src/test/java/com/example/bigqueryconnection/GetConnectionIT.java

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+/*
+ * 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.bigqueryconnection;
+
+import static com.google.common.truth.Truth.assertThat;
+import static junit.framework.TestCase.assertNotNull;
+
+import com.google.cloud.bigquery.connection.v1.CloudSqlCredential;
+import com.google.cloud.bigquery.connection.v1.CloudSqlProperties;
+import com.google.cloud.bigquery.connection.v1.Connection;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.util.UUID;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class GetConnectionIT {
+
+  private static final Logger LOG = Logger.getLogger(GetConnectionIT.class.getName());
+  private static final String LOCATION = "US";
+  private static final String REGION = "us-central1";
+  private static final String PROJECT_ID = requireEnvVar("GOOGLE_CLOUD_PROJECT");
+  private static final String MY_SQL_DATABASE = requireEnvVar("MY_SQL_DATABASE");
+  private static final String MY_SQL_INSTANCE = requireEnvVar("MY_SQL_INSTANCE");
+  private static final String DB_USER = requireEnvVar("DB_USER");
+  private static final String DB_PWD = requireEnvVar("DB_PWD");
+
+  private String connectionId;
+  private ByteArrayOutputStream bout;
+  private PrintStream out;
+  private PrintStream originalPrintStream;
+
+  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");
+    requireEnvVar("MY_SQL_DATABASE");
+    requireEnvVar("MY_SQL_INSTANCE");
+    requireEnvVar("DB_USER");
+    requireEnvVar("DB_PWD");
+  }
+
+  @Before
+  public void setUp() throws IOException {
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    originalPrintStream = System.out;
+    System.setOut(out);
+    // create a temporary connection
+    connectionId = "MY_CONNECTION_TEST_" + UUID.randomUUID().toString().substring(0, 8);
+    String instanceId = String.format("%s:%s:%s", PROJECT_ID, REGION, MY_SQL_INSTANCE);
+    CloudSqlCredential cloudSqlCredential =
+        CloudSqlCredential.newBuilder().setUsername(DB_USER).setPassword(DB_PWD).build();
+    CloudSqlProperties cloudSqlProperties =
+        CloudSqlProperties.newBuilder()
+            .setType(CloudSqlProperties.DatabaseType.MYSQL)
+            .setDatabase(MY_SQL_DATABASE)
+            .setInstanceId(instanceId)
+            .setCredential(cloudSqlCredential)
+            .build();
+    Connection connection = Connection.newBuilder().setCloudSql(cloudSqlProperties).build();
+    CreateConnection.createConnection(PROJECT_ID, LOCATION, connectionId, connection);
+  }
+
+  @After
+  public void tearDown() throws IOException {
+    // Clean up
+    DeleteConnection.deleteConnection(PROJECT_ID, LOCATION, connectionId);
+    // restores print statements in the original method
+    System.out.flush();
+    System.setOut(originalPrintStream);
+    LOG.log(Level.INFO, bout.toString());
+  }
+
+  @Test
+  public void testGetConnection() throws IOException {
+    GetConnection.getConnection(PROJECT_ID, LOCATION, connectionId);
+    assertThat(bout.toString()).contains("Connection info retrieved successfully :");
+  }
+}