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.apex.malhar.stream.api.impl;
  
  import org.apache.apex.malhar.contrib.kafka.KafkaSinglePortStringInputOperator;
  import org.apache.apex.malhar.kafka.KafkaSinglePortInputOperator;
  import org.apache.apex.malhar.kafka.PartitionStrategy;
  import org.apache.apex.malhar.lib.fs.LineByLineFileInputOperator;
  import org.apache.apex.malhar.stream.api.ApexStream;
  import org.apache.apex.malhar.stream.api.Option;
  import org.apache.hadoop.classification.InterfaceStability;
  
  import com.datatorrent.api.InputOperator;
  import com.datatorrent.api.Operator;
  
  import static org.apache.apex.malhar.stream.api.Option.Options.name;
  
  /**
   * A Factory class to build stream from different input sources
   *
   * @since 3.4.0
   */
  @InterfaceStability.Evolving
  public class StreamFactory
  {
    /**
     * Create a stream of string tuples from reading files in hdfs folder line by line
     * @param folderName
     * @param opts
     * @return
     */
    public static ApexStream<String> fromFolder(String folderName, Option... opts)
    {
      LineByLineFileInputOperator fileLineInputOperator = new LineByLineFileInputOperator();
      fileLineInputOperator.setDirectory(folderName);
      ApexStreamImpl<String> newStream = new ApexStreamImpl<>();
      return newStream.addOperator(fileLineInputOperator, null, fileLineInputOperator.output, opts);
    }
  
    public static ApexStream<String> fromFolder(String folderName)
    {
      return fromFolder(folderName, name("FolderScanner"));
    }
  
    public static ApexStream<String> fromKafka08(String zookeepers, String topic)
    {
      return fromKafka08(zookeepers, topic, name("Kafka08Input"));
    }
  
    /**
     * Create a stream of string reading input from kafka 0.8
     * @param zookeepers
     * @param topic
     * @param opts
     * @return
     */
    public static ApexStream<String> fromKafka08(String zookeepers, String topic, Option... opts)
    {
      KafkaSinglePortStringInputOperator kafkaSinglePortStringInputOperator = new KafkaSinglePortStringInputOperator();
      kafkaSinglePortStringInputOperator.getConsumer().setTopic(topic);
      kafkaSinglePortStringInputOperator.getConsumer().setZookeeper(zookeepers);
      ApexStreamImpl<String> newStream = new ApexStreamImpl<>();
      return newStream.addOperator(kafkaSinglePortStringInputOperator, null, kafkaSinglePortStringInputOperator.outputPort);
    }
  
    /**
     * Create a stream with any input operator
     * @param operator
     * @param outputPort
     * @param opts
     * @param <T>
     * @return
     */
    public static <T> ApexStream<T> fromInput(InputOperator operator, Operator.OutputPort<T> outputPort, Option... opts)
    {
      ApexStreamImpl<T> newStream = new ApexStreamImpl<>();
      return newStream.addOperator(operator, null, outputPort, opts);
    }
  
    /**
     * Create stream of byte array messages from kafka 0.9
     * @param brokers
     * @param topic
     * @param opts
     * @return
     */
    public static ApexStream<byte[]> fromKafka09(String brokers, String topic, Option... opts)
    {
      KafkaSinglePortInputOperator kafkaInput = new KafkaSinglePortInputOperator();
      kafkaInput.setClusters(brokers);
      kafkaInput.setTopics(topic);
      ApexStreamImpl<String> newStream = new ApexStreamImpl<>();
      return newStream.addOperator(kafkaInput, null, kafkaInput.outputPort, opts);
    }
  
    /**
     * Create stream of byte array messages from kafka 0.9 with more partition options
     */
    public static ApexStream<byte[]> fromKafka09(String brokers, String topic, PartitionStrategy strategy, int partitionNumber, Option... opts)
    {
      KafkaSinglePortInputOperator kafkaInput = new KafkaSinglePortInputOperator();
      kafkaInput.setClusters(brokers);
      kafkaInput.setTopics(topic);
      kafkaInput.setStrategy(strategy.name());
      kafkaInput.setInitialPartitionCount(partitionNumber);
      ApexStreamImpl<String> newStream = new ApexStreamImpl<>();
      return newStream.addOperator(kafkaInput, null, kafkaInput.outputPort, opts);
    }
  
  
  }
  