/*
* Copyright © 2016 Cask Data, Inc.
*
* 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 co.cask.cdap.etl.batch.mapreduce;
import co.cask.cdap.api.dataset.lib.KeyValue;
import co.cask.cdap.api.mapreduce.MapReduceTaskContext;
/**
* Wrapper around writing to a mapreduce context.
* This abstraction is required because if there is just one output for a mapreduce,
* we must do context.write(key, value) instead of context.write(name, key, value).
* See CDAP-3628 for more detail
*
* @param <KEY_OUT> the output key type
* @param <VAL_OUT> the output value type
*/
abstract class OutputWriter<KEY_OUT, VAL_OUT> {
protected final MapReduceTaskContext<KEY_OUT, VAL_OUT> context;
public OutputWriter(MapReduceTaskContext<KEY_OUT, VAL_OUT> context) {
this.context = context;
}
protected abstract void write(String sinkName, KeyValue<KEY_OUT, VAL_OUT> output) throws Exception;
}