library/src/main/java/com/datatorrent/lib/converter/MapToKeyValuePairConverter.java

/*
 * Copyright (c) 2015 DataTorrent, Inc. ALL Rights Reserved.
 *
 * Licensed 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 com.datatorrent.lib.converter;

import java.util.Map;
import java.util.Map.Entry;

import com.datatorrent.lib.util.KeyValPair;

import com.datatorrent.api.BaseOperator;
import com.datatorrent.api.DefaultInputPort;
import com.datatorrent.api.DefaultOutputPort;

/**
 * 
 * This operator outputs key value pair for each entry in input Map 
 * 
 * @displayName Map to key-value pair converter
 * @category Converter
 * 
 */
public class MapToKeyValuePairConverter<K, V> extends BaseOperator {

  /**
   * Input port which accepts Map<K, V>.
   */
  public final transient DefaultInputPort<Map<K, V>> input = new DefaultInputPort<Map<K, V>>()
  {
    @Override
    public void process(Map<K, V> tuple)
    { 
      for(Entry<K, V> entry:tuple.entrySet())
      {
        output.emit(new KeyValPair<K, V>(entry.getKey(), entry.getValue()));  
      }      
    }
  };

  /*
   * Output port which outputs KeyValue pair for each entry in Map
   */
  public final transient DefaultOutputPort<KeyValPair<K, V>> output = new DefaultOutputPort<KeyValPair<K, V>>();
}