feat: new sample - load: GCS parquet replace existing table (#101)

Author: stephaniewang526

samples/src/main/java/com/example/bigquery/LoadParquetReplaceTable.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;
+
+// [START bigquery_load_table_gcs_parquet_truncate]
+
+import com.google.cloud.bigquery.BigQuery;
+import com.google.cloud.bigquery.BigQueryException;
+import com.google.cloud.bigquery.BigQueryOptions;
+import com.google.cloud.bigquery.FormatOptions;
+import com.google.cloud.bigquery.Job;
+import com.google.cloud.bigquery.JobInfo;
+import com.google.cloud.bigquery.JobInfo.WriteDisposition;
+import com.google.cloud.bigquery.LoadJobConfiguration;
+import com.google.cloud.bigquery.TableId;
+import java.math.BigInteger;
+
+public class LoadParquetReplaceTable {
+
+  public static void runLoadParquetReplaceTable() {
+    // TODO(developer): Replace these variables before running the sample.
+    String datasetName = "MY_DATASET_NAME";
+    loadParquetReplaceTable(datasetName);
+  }
+
+  public static void loadParquetReplaceTable(String datasetName) {
+    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();
+
+      // Imports a GCS file into a table and overwrites table data if table already exists.
+      // This sample loads CSV file at:
+      // https://storage.googleapis.com/cloud-samples-data/bigquery/us-states/us-states.csv
+      String sourceUri = "gs://cloud-samples-data/bigquery/us-states/us-states.parquet";
+      TableId tableId = TableId.of(datasetName, "us_states");
+
+      // For more information on LoadJobConfiguration see:
+      // https://googleapis.dev/java/google-cloud-clients/latest/com/google/cloud/bigquery/LoadJobConfiguration.Builder.html
+      LoadJobConfiguration configuration =
+          LoadJobConfiguration.builder(tableId, sourceUri)
+              .setFormatOptions(FormatOptions.parquet())
+              // Set the write disposition to overwrite existing table data.
+              .setWriteDisposition(WriteDisposition.WRITE_TRUNCATE)
+              .build();
+
+      // For more information on Job see:
+      // https://googleapis.dev/java/google-cloud-clients/latest/index.html?com/google/cloud/bigquery/package-summary.html
+      // Load the table
+      Job job = bigquery.create(JobInfo.of(configuration));
+
+      // Load data from a GCS parquet file into the table
+      // Blocks until this load table job completes its execution, either failing or succeeding.
+      Job completedJob = job.waitFor();
+      if (completedJob == null) {
+        System.out.println("Job not executed since it no longer exists.");
+        return;
+      } else if (completedJob.getStatus().getError() != null) {
+        System.out.println(
+            "BigQuery was unable to load into the table due to an error: \n"
+                + job.getStatus().getError());
+        return;
+      }
+
+      // Check number of rows loaded into the table
+      BigInteger numRows = bigquery.getTable(tableId).getNumRows();
+      System.out.printf("Loaded %d rows. \n", numRows);
+
+      System.out.println("GCS parquet overwrote existing table successfully.");
+    } catch (BigQueryException | InterruptedException e) {
+      System.out.println("Table extraction job was interrupted. \n" + e.toString());
+    }
+  }
+}
+// [END bigquery_load_table_gcs_parquet_truncate]

samples/src/test/java/com/example/bigquery/LoadParquetReplaceTableIT.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 static junit.framework.TestCase.assertNotNull;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class LoadParquetReplaceTableIT {
+  private ByteArrayOutputStream bout;
+  private PrintStream out;
+
+  private static final String BIGQUERY_DATASET_NAME = System.getenv("BIGQUERY_DATASET_NAME");
+
+  private static void requireEnvVar(String varName) {
+    assertNotNull(
+        "Environment variable " + varName + " is required to perform these tests.",
+        System.getenv(varName));
+  }
+
+  @BeforeClass
+  public static void checkRequirements() {
+    requireEnvVar("BIGQUERY_DATASET_NAME");
+  }
+
+  @Before
+  public void setUp() {
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    System.setOut(out);
+  }
+
+  @After
+  public void tearDown() {
+    System.setOut(null);
+  }
+
+  @Test
+  public void testLoadParquetReplaceTable() {
+    LoadParquetReplaceTable.loadParquetReplaceTable(BIGQUERY_DATASET_NAME);
+    assertThat(bout.toString()).contains("GCS parquet overwrote existing table successfully.");
+  }
+}