docs(bigquery): add QueryArrow code sample and document JDK 17+ JVM requirements (#14437)

Adds a QueryArrow code sample demonstrating zero-copy VectorSchemaRoot
streaming with try-with-resources. Also documents the required
--add-opens JVM flag in queryArrow Javadoc for applications running on
JDK 17+.

Author: jinseopkim0

java-bigquery/README.md

@@ -197,6 +197,7 @@ Samples are in the [`samples/`](https://github.com/googleapis/java-bigquery/tree
 | Load Partitioned Table | [source code](https://github.com/googleapis/java-bigquery/blob/main/samples/snippets/src/main/java/com/example/bigquery/LoadPartitionedTable.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/LoadPartitionedTable.java) |
 | Load Table Clustered | [source code](https://github.com/googleapis/java-bigquery/blob/main/samples/snippets/src/main/java/com/example/bigquery/LoadTableClustered.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/LoadTableClustered.java) |
 | Nested Repeated Schema | [source code](https://github.com/googleapis/java-bigquery/blob/main/samples/snippets/src/main/java/com/example/bigquery/NestedRepeatedSchema.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/NestedRepeatedSchema.java) |
+| Query Arrow | [source code](https://github.com/googleapis/java-bigquery/blob/main/samples/snippets/src/main/java/com/example/bigquery/QueryArrow.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryArrow.java) |
 | Query Batch | [source code](https://github.com/googleapis/java-bigquery/blob/main/samples/snippets/src/main/java/com/example/bigquery/QueryBatch.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryBatch.java) |
 | Query Clustered Table | [source code](https://github.com/googleapis/java-bigquery/blob/main/samples/snippets/src/main/java/com/example/bigquery/QueryClusteredTable.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryClusteredTable.java) |
 | Query Destination Table Cmek | [source code](https://github.com/googleapis/java-bigquery/blob/main/samples/snippets/src/main/java/com/example/bigquery/QueryDestinationTableCmek.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquery&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquery/QueryDestinationTableCmek.java) |

java-bigquery/google-cloud-bigquery/src/main/java/com/google/cloud/bigquery/BigQuery.java

@@ -1650,6 +1650,14 @@ TableResult query(QueryJobConfiguration configuration, JobId jobId, JobOption...
    * <p><b>Prerequisite:</b> Requires the BigQuery Storage Read API ({@code
    * bigquerystorage.googleapis.com}) to be enabled on your GCP project.
    *
+   * <p><b>JVM Requirements (Java 16+):</b> Apache Arrow uses internal {@code java.nio}
+   * DirectByteBuffer access for off-heap buffer management. Applications running on Java 16 or
+   * newer must supply the following JVM argument:
+   *
+   * <pre>{@code
+   * --add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED
+   * }</pre>
+   *
    * @param configuration the query configuration
    * @param options query options
    * @return an {@link ArrowQueryResult} streaming Arrow vectors
@@ -1675,6 +1683,14 @@ default ArrowQueryResult queryArrow(QueryJobConfiguration configuration, JobOpti
    * <p><b>Prerequisite:</b> Requires the BigQuery Storage Read API ({@code
    * bigquerystorage.googleapis.com}) to be enabled on your GCP project.
    *
+   * <p><b>JVM Requirements (Java 16+):</b> Apache Arrow uses internal {@code java.nio}
+   * DirectByteBuffer access for off-heap buffer management. Applications running on Java 16 or
+   * newer must supply the following JVM argument:
+   *
+   * <pre>{@code
+   * --add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED
+   * }</pre>
+   *
    * @param configuration the query configuration
    * @param jobId the job ID to use
    * @param options query options

java-bigquery/samples/snippets/src/main/java/com/example/bigquery/QueryArrow.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2026 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_query_arrow]
+
+import com.google.cloud.bigquery.ArrowQueryResult;
+import com.google.cloud.bigquery.BigQuery;
+import com.google.cloud.bigquery.BigQueryException;
+import com.google.cloud.bigquery.BigQueryOptions;
+import com.google.cloud.bigquery.QueryJobConfiguration;
+import org.apache.arrow.vector.FieldVector;
+import org.apache.arrow.vector.VectorSchemaRoot;
+
+public class QueryArrow {
+
+  public static void main(String[] args) {
+    // TODO(developer): Replace this query before running the sample.
+    String query =
+        "SELECT corpus, count(*) as corpus_count "
+            + "FROM `bigquery-public-data.samples.shakespeare` GROUP BY corpus;";
+    queryArrow(query);
+  }
+
+  /**
+   * Runs a query and streams Apache Arrow {@link VectorSchemaRoot} batches directly for zero-copy
+   * vector access.
+   *
+   * <p><b>JVM Requirements (Java 16+):</b> Applications running on Java 16 or newer must supply the
+   * following JVM option to allow Apache Arrow's memory allocator access to internal
+   * DirectByteBuffer:
+   *
+   * <pre>{@code --add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED}</pre>
+   */
+  public static void queryArrow(String query) {
+    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();
+
+      // Create the query configuration.
+      QueryJobConfiguration queryConfig = QueryJobConfiguration.newBuilder(query).build();
+
+      // Execute the query using queryArrow. Always close ArrowQueryResult to free off-heap memory.
+      try (ArrowQueryResult result = bigquery.queryArrow(queryConfig)) {
+        long totalRows = 0;
+        for (VectorSchemaRoot root : result) {
+          int rowCount = root.getRowCount();
+          totalRows += rowCount;
+          FieldVector corpusVector = root.getVector("corpus");
+          FieldVector countVector = root.getVector("corpus_count");
+
+          for (int i = 0; i < rowCount; i++) {
+            System.out.print("corpus:" + corpusVector.getObject(i));
+            System.out.print(", count:" + countVector.getObject(i));
+            System.out.println();
+          }
+        }
+        System.out.println("Arrow query ran successfully. Total rows: " + totalRows);
+      }
+    } catch (BigQueryException e) {
+      System.out.println("Arrow query did not run \n" + e.toString());
+    } catch (InterruptedException e) {
+      System.out.println("Arrow query was interrupted \n" + e.toString());
+      Thread.currentThread().interrupt();
+    }
+  }
+}
+// [END bigquery_query_arrow]

java-bigquery/samples/snippets/src/test/java/com/example/bigquery/QueryArrowIT.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2026 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 java.util.logging.Level;
+import java.util.logging.Logger;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class QueryArrowIT {
+
+  private final Logger log = Logger.getLogger(this.getClass().getName());
+  private ByteArrayOutputStream bout;
+  private PrintStream out;
+  private PrintStream originalPrintStream;
+
+  @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, "\n" + bout.toString());
+  }
+
+  @Test
+  public void testQueryArrow() {
+    String query =
+        "SELECT corpus, count(*) as corpus_count "
+            + "FROM `bigquery-public-data.samples.shakespeare` GROUP BY corpus;";
+
+    QueryArrow.queryArrow(query);
+    assertThat(bout.toString()).contains("Arrow query ran successfully");
+  }
+}