docs(samples): add list jobs (#554)

* docs(samples): add list jobs

* docs(samples): update code

samples/snippets/src/main/java/com/example/bigquery/ListJobs.java

@@ -0,0 +1,50 @@
+/*
+ * 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.bigquery;
+
+// [START bigquery_list_jobs]
+import com.google.api.gax.paging.Page;
+import com.google.cloud.bigquery.BigQuery;
+import com.google.cloud.bigquery.BigQueryException;
+import com.google.cloud.bigquery.BigQueryOptions;
+import com.google.cloud.bigquery.Job;
+
+// Sample to get list of jobs
+public class ListJobs {
+
+  public static void runListJobs() {
+    listJobs();
+  }
+
+  public static void listJobs() {
+    try {
+      // Initialize client that will be used to send requests. This client only needs to be created
+      // once, and can be reused for multiple requests.
+      BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();
+
+      Page<Job> jobs = bigquery.listJobs(BigQuery.JobListOption.pageSize(10));
+      if (jobs == null) {
+        System.out.println("Dataset does not contain any jobs.");
+        return;
+      }
+      jobs.getValues().forEach(job -> System.out.printf("Success! Job ID: %s", job.getJobId()));
+    } catch (BigQueryException e) {
+      System.out.println("Jobs not listed in dataset due to error: \n" + e.toString());
+    }
+  }
+}
+// [END bigquery_list_jobs]

samples/snippets/src/test/java/com/example/bigquery/ListJobsIT.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.bigquery;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ListJobsIT {
+
+  private ByteArrayOutputStream bout;
+  private PrintStream out;
+
+  @Before
+  public void setUp() {
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    System.setOut(out);
+
+    // Create a new job
+    String query =
+        "SELECT name"
+            + " FROM `bigquery-public-data.usa_names.usa_1910_2013`"
+            + " WHERE state = 'TX'"
+            + " LIMIT 100;";
+    CreateJob.createJob(query);
+
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    System.setOut(out);
+  }
+
+  @After
+  public void tearDown() {
+    // Clean up
+    System.setOut(null);
+  }
+
+  @Test
+  public void testListJobs() {
+    ListJobs.listJobs();
+    assertThat(bout.toString()).contains("Success! Job ID");
+  }
+}