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.examples.mroperator;
  
  import java.util.StringTokenizer;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.mapred.InputFormat;
  import org.apache.hadoop.mapred.Mapper;
  import org.apache.hadoop.mapred.Reducer;
  import com.datatorrent.api.DAG;
  import com.datatorrent.api.StreamingApplication;
  import com.datatorrent.api.annotation.ApplicationAnnotation;
  
  
  /**
   * <p>
   * Abstract MapReduceApplication class.
   * </p>
   *
   * @since 0.9.0
   */
  @ApplicationAnnotation(name = "MapReduceExample")
  public abstract class MapReduceApplication<K1, V1, K2, V2> implements StreamingApplication
  {
    Class<? extends InputFormat<K1, V1>> inputFormat;
    Class<? extends Mapper<K1, V1, K2, V2>> mapClass;
    Class<? extends Reducer<K2, V2, K2, V2>> reduceClass;
    Class<? extends Reducer<K2, V2, K2, V2>> combineClass;
  
    public Class<? extends Reducer<K2, V2, K2, V2>> getCombineClass()
    {
      return combineClass;
    }
  
    public void setCombineClass(Class<? extends Reducer<K2, V2, K2, V2>> combineClass)
    {
      this.combineClass = combineClass;
    }
  
    public void setInputFormat(Class<? extends InputFormat<K1, V1>> inputFormat)
    {
      this.inputFormat = inputFormat;
    }
  
    public Class<? extends Mapper<K1, V1, K2, V2>> getMapClass()
    {
      return mapClass;
    }
  
    public void setMapClass(Class<? extends Mapper<K1, V1, K2, V2>> mapClass)
    {
      this.mapClass = mapClass;
    }
  
    public Class<? extends Reducer<K2, V2, K2, V2>> getReduceClass()
    {
      return reduceClass;
    }
  
    public void setReduceClass(Class<? extends Reducer<K2, V2, K2, V2>> reduceClass)
    {
      this.reduceClass = reduceClass;
    }
  
  
    @Override
    public void populateDAG(DAG dag, Configuration conf)
    {
      String configurationFilePath = conf.get(this.getClass().getSimpleName() + ".configFile", "");
  
      MapOperator<K1, V1, K2, V2> inputOperator = dag.addOperator("Mapper", new MapOperator<K1, V1, K2, V2>());
      inputOperator.setInputFormatClass(inputFormat);
  
      String configFileName = null;
      if (configurationFilePath != null && !configurationFilePath.isEmpty()) {
        StringTokenizer configFileTokenizer = new StringTokenizer(configurationFilePath, "/");
        configFileName = configFileTokenizer.nextToken();
        while (configFileTokenizer.hasMoreTokens()) {
          configFileName = configFileTokenizer.nextToken();
        }
      }
  
      inputOperator.setMapClass(mapClass);
      inputOperator.setConfigFile(configFileName);
      inputOperator.setCombineClass(combineClass);
  
      ReduceOperator<K2, V2, K2, V2> reduceOpr = dag.addOperator("Reducer", new ReduceOperator<K2, V2, K2, V2>());
      reduceOpr.setReduceClass(reduceClass);
      reduceOpr.setConfigFile(configFileName);
  
      HdfsKeyValOutputOperator<K2, V2> console = dag.addOperator("Console", new HdfsKeyValOutputOperator<K2, V2>());
  
      dag.addStream("Mapped-Output", inputOperator.output, reduceOpr.input);
      dag.addStream("Mapper-Count", inputOperator.outputCount, reduceOpr.inputCount);
      dag.addStream("Reduced-Output", reduceOpr.output, console.input);
    }
  }
  