com.samelamin.spark.bigquery.BigQueryServiceFactory Maven / Gradle / Ivy
/*
* Copyright (c) 2015 Google Inc.
*
* 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.samelamin.spark.bigquery;
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.services.bigquery.Bigquery;
import com.google.api.services.bigquery.BigqueryScopes;
import java.io.IOException;
import java.util.Collection;
/**
* This class creates our Service to connect to BigQuery including auth.
*/
public final class BigQueryServiceFactory {
/**
* Private constructor to disable creation of this utility Factory class.
*/
private BigQueryServiceFactory() {
}
/**
* Singleton service used through the app.
*/
private static Bigquery service = null;
/**
* Mutex created to create the singleton in thread-safe fashion.
*/
private static Object serviceLock = new Object();
/**
* Threadsafe Factory that provides an authorized BigQuery service.
*
* @return The BigQuery service
* @throws IOException Throw if there is an error connecting to BigQuery.
*/
public static Bigquery getService() throws IOException {
if (service == null) {
synchronized (serviceLock) {
if (service == null) {
service = createAuthorizedClient();
}
}
}
return service;
}
/**
* Creates an authorized client to Google BigQuery.
*
* @return The BigQuery Service
* @throws IOException Thrown if there is an error connecting
*/
private static Bigquery createAuthorizedClient() throws IOException {
// Create the credential
HttpTransport transport = new NetHttpTransport();
JsonFactory jsonFactory = new JacksonFactory();
GoogleCredential credential = GoogleCredential.getApplicationDefault(transport, jsonFactory);
// Depending on the environment that provides the default credentials (e.g. Compute Engine, App
// Engine), the credentials may require us to specify the scopes we need explicitly.
// Check for this case, and inject the BigQuery scope if required.
if (credential.createScopedRequired()) {
Collection bigqueryScopes = BigqueryScopes.all();
credential = credential.createScoped(bigqueryScopes);
}
return new Bigquery.Builder(transport, jsonFactory, credential)
.setApplicationName("BigQuery Spark Stream")
.build();
}
}