/***********************************************************************************************************************
*
* 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.api.java.functions;
import java.util.Iterator;
import eu.stratosphere.util.Collector;
public abstract class GroupReduceIterator<IN, OUT> extends GroupReduceFunction<IN, OUT> {
private static final long serialVersionUID = 1L;
public abstract Iterator<OUT> reduceGroup(Iterator<IN> values) throws Exception;
// -------------------------------------------------------------------------------------------
@Override
public final void reduce(Iterator<IN> values, Collector<OUT> out) throws Exception {
for (Iterator<OUT> iter = reduceGroup(values); iter.hasNext(); ) {
out.collect(iter.next());
}
}
}