content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.carbondata.examples.sdk;
  
  import java.util.List;
  
  import org.apache.carbondata.common.logging.LogServiceFactory;
  import org.apache.carbondata.core.metadata.datatype.DataTypes;
  import org.apache.carbondata.core.scan.expression.ColumnExpression;
  import org.apache.carbondata.core.scan.expression.LiteralExpression;
  import org.apache.carbondata.core.scan.expression.conditional.EqualToExpression;
  import org.apache.carbondata.core.util.path.CarbonTablePath;
  import org.apache.carbondata.sdk.file.CarbonReader;
  
  import static org.apache.carbondata.sdk.file.utils.SDKUtil.listFiles;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.log4j.Logger;
  
  import static org.apache.hadoop.fs.s3a.Constants.ACCESS_KEY;
  import static org.apache.hadoop.fs.s3a.Constants.ENDPOINT;
  import static org.apache.hadoop.fs.s3a.Constants.SECRET_KEY;
  
  /**
   * Example for testing carbonReader on S3
   */
  public class SDKS3ReadExample {
    public static void main(String[] args) throws Exception {
      Logger logger = LogServiceFactory.getLogService(SDKS3ReadExample.class.getName());
      int parameterLength = 3;
      if (args == null || args.length < parameterLength) {
        logger.error("Usage: java CarbonS3Example: <access-key> <secret-key>"
            + "<s3-endpoint> [table-path-on-s3]");
        System.exit(0);
      }
  
      String path = "s3a://obs-xubo4/sdkdata/test";
      if (args.length > parameterLength) {
        path = args[3];
      }
  
      // 1. read with file list
      Configuration conf = new Configuration();
  
      conf.set(ACCESS_KEY, args[0]);
      conf.set(SECRET_KEY, args[1]);
      conf.set(ENDPOINT, args[2]);
      List fileLists = listFiles(path, CarbonTablePath.CARBON_DATA_EXT, conf);
  
      // Read data
      EqualToExpression equalToExpression = new EqualToExpression(
          new ColumnExpression("name", DataTypes.STRING),
          new LiteralExpression("robot1", DataTypes.STRING));
  
      CarbonReader reader = CarbonReader
          .builder()
          .projection(new String[]{"name", "age"})
          .filter(equalToExpression)
          .withHadoopConf(ACCESS_KEY, args[0])
          .withHadoopConf(SECRET_KEY, args[1])
          .withHadoopConf(ENDPOINT, args[2])
          .withFileLists(fileLists)
          .build();
  
      System.out.println("\nData:");
      int i = 0;
      int count = 20;
      while (i < count && reader.hasNext()) {
        Object[] row = (Object[]) reader.readNextRow();
        System.out.println(row[0] + " " + row[1]);
        i++;
      }
      System.out.println("\nFinished");
      reader.close();
  
      // Read without filter
      CarbonReader reader2 = CarbonReader
          .builder(path, "_temp")
          .projection(new String[]{"name", "age"})
          .withHadoopConf(ACCESS_KEY, args[0])
          .withHadoopConf(SECRET_KEY, args[1])
          .withHadoopConf(ENDPOINT, args[2])
          .build();
  
      System.out.println("\nData:");
      i = 0;
      while (i < count && reader2.hasNext()) {
        Object[] row = (Object[]) reader2.readNextRow();
        System.out.println(row[0] + " " + row[1]);
        i++;
      }
      System.out.println("\nFinished");
      reader2.close();
    }
  }
  