BigqueryServiceFactory.java

package com.google.cloud.bigquery.samples;

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;

/**
 * TODO: Insert description here. (generated by elibixby)
 */
public class BigqueryServiceFactory {
  
  private static Bigquery service = null;
  private static Object service_lock = new Object();
  
  public static Bigquery getService() throws IOException{
    if(service==null){
      synchronized(service_lock){
        if(service==null){
          service=createAuthorizedClient();
        }
      }
    }
    return service;
  }
  
  // [START get_service]
  private static Bigquery createAuthorizedClient() throws IOException {
    Collection<String> BIGQUERY_SCOPES = BigqueryScopes.all();
    HttpTransport TRANSPORT = new NetHttpTransport();
    JsonFactory JSON_FACTORY = new JacksonFactory();
    GoogleCredential credential = GoogleCredential.getApplicationDefault(TRANSPORT, JSON_FACTORY);
    if(credential.createScopedRequired()){
      credential = credential.createScoped(BIGQUERY_SCOPES);
    }
    return new Bigquery.Builder(TRANSPORT, JSON_FACTORY, credential).setApplicationName("BigQuery Samples").build();
  }
  // [END get_service]

}