docs(samples): add quick start (#143)

* docs(samples): add quick start

* docs(samples): modify code

Author: Praful Makani

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

@@ -0,0 +1,55 @@
+/*
+ * 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_quickstart]
+import com.google.cloud.bigquery.connection.v1.ListConnectionsRequest;
+import com.google.cloud.bigquery.connection.v1.LocationName;
+import com.google.cloud.bigqueryconnection.v1.ConnectionServiceClient;
+import java.io.IOException;
+
+// Sample to demonstrates basic usage of the BigQuery connection API.
+public class QuickstartSample {
+
+  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";
+    listConnections(projectId, location);
+  }
+
+  public static void listConnections(String projectId, String location) throws IOException {
+    try (ConnectionServiceClient connectionServiceClient = ConnectionServiceClient.create()) {
+      LocationName parent = LocationName.of(projectId, location);
+      int pageSize = 10;
+      ListConnectionsRequest request =
+          ListConnectionsRequest.newBuilder()
+              .setParent(parent.toString())
+              .setPageSize(pageSize)
+              .build();
+      ConnectionServiceClient.ListConnectionsPagedResponse response =
+          connectionServiceClient.listConnections(request);
+
+      // Print the results.
+      System.out.println("List of connections:");
+      response
+          .iterateAll()
+          .forEach(connection -> System.out.println("Connection Name: " + connection.getName()));
+    }
+  }
+}
+// [END bigqueryconnection_quickstart]

samples/snippets/src/test/java/com/example/bigqueryconnection/QuickstartSampleIT.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 java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+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 QuickstartSampleIT {
+
+  private static final Logger LOG = Logger.getLogger(QuickstartSampleIT.class.getName());
+  private static final String PROJECT_ID = System.getenv("GOOGLE_CLOUD_PROJECT");
+
+  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");
+  }
+
+  @Before
+  public void setUp() {
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    originalPrintStream = System.out;
+    System.setOut(out);
+  }
+
+  @After
+  public void tearDown() {
+    // restores print statements in the original method
+    System.out.flush();
+    System.setOut(originalPrintStream);
+    LOG.log(Level.INFO, bout.toString());
+  }
+
+  @Test
+  public void testQuickstart() throws IOException {
+    QuickstartSample.listConnections(PROJECT_ID, "US");
+    assertThat(bout.toString()).contains("List of connections:");
+  }
+}