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.transform;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.apex.malhar.lib.function.Function;
  import org.apache.apex.malhar.lib.function.FunctionOperator;
  import org.apache.apex.malhar.lib.function.FunctionOperatorUtil;
  import org.apache.apex.malhar.lib.transform.TransformOperator;
  import org.apache.hadoop.conf.Configuration;
  
  import com.google.common.annotations.VisibleForTesting;
  
  import com.datatorrent.api.Context;
  import com.datatorrent.api.DAG;
  import com.datatorrent.api.StreamingApplication;
  import com.datatorrent.api.annotation.ApplicationAnnotation;
  import com.datatorrent.common.partitioner.StatelessPartitioner;
  
  @ApplicationAnnotation(name = "TransformExample")
  /**
   * @since 3.7.0
   */
  public class SimpleTransformApplication implements StreamingApplication
  {
    @VisibleForTesting
    Function.MapFunction<Object, ?> outputFn = FunctionOperatorUtil.CONSOLE_SINK_FN;
  
    @VisibleForTesting
    POJOGenerator pojoDataGenerator;
  
    @Override
    public void populateDAG(DAG dag, Configuration conf)
    {
      pojoDataGenerator = dag.addOperator("Input", new POJOGenerator());
      TransformOperator transform = dag.addOperator("Process", new TransformOperator());
      // Set expression map
      Map<String, String> expMap = new HashMap<>();
      expMap.put("name", "{$.firstName}.concat(\" \").concat({$.lastName})");
      expMap.put("age", "(new java.util.Date()).getYear() - {$.dateOfBirth}.getYear()");
      expMap.put("address", "{$.address}.toLowerCase()");
      transform.setExpressionMap(expMap);
      FunctionOperator.MapFunctionOperator<Object, ?> output = dag.addOperator("out",
          new FunctionOperator.MapFunctionOperator<>(outputFn));
  
      dag.addStream("InputToTransform", pojoDataGenerator.output, transform.input);
      dag.addStream("TransformToOutput", transform.output, output.input);
  
      dag.setInputPortAttribute(transform.input, Context.PortContext.TUPLE_CLASS, CustomerEvent.class);
      dag.setOutputPortAttribute(transform.output, Context.PortContext.TUPLE_CLASS, CustomerInfo.class);
      setPartitioner(dag,conf,transform);
    }
  
    void setPartitioner(DAG dag,Configuration conf, TransformOperator transform)
    {
      dag.setAttribute(transform, Context.OperatorContext.PARTITIONER,
          new StatelessPartitioner<TransformOperator>(2));
    }
  }
  