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/***********************************************************************************************************************
 * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
 *
 * 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 eu.stratosphere.nephele.example.union;

import eu.stratosphere.core.io.StringRecord;
import eu.stratosphere.nephele.io.MutableRecordReader;
import eu.stratosphere.nephele.io.RecordWriter;
import eu.stratosphere.nephele.io.UnionRecordReader;
import eu.stratosphere.nephele.template.AbstractTask;

public class UnionTask extends AbstractTask {

	private UnionRecordReader input;

	private RecordWriter output;

	@Override
	public void registerInputOutput() {
		@SuppressWarnings("unchecked")
		MutableRecordReader[] recordReaders = (MutableRecordReader[]) new MutableRecordReader[2];
		recordReaders[0] = new MutableRecordReader(this);
		recordReaders[1] = new MutableRecordReader(this);

		this.input = new UnionRecordReader(recordReaders, StringRecord.class);
		this.output = new RecordWriter(this, StringRecord.class);
	}

	@Override
	public void invoke() throws Exception {
		while (this.input.hasNext()) {
			this.output.emit(this.input.next());
		}
	}
}