Java tutorial
/* * * * * 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.crunch.impl.spark.fn; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import org.apache.crunch.Pair; import org.apache.crunch.impl.spark.ByteArray; import org.apache.crunch.impl.spark.serde.SerDe; import org.apache.spark.api.java.function.Function; import scala.Tuple2; import java.util.List; public class ReduceInputFunction<K, V> implements Function<Tuple2<ByteArray, Iterable<byte[]>>, Pair<K, Iterable<V>>> { private final SerDe<K> keySerDe; private final SerDe<V> valueSerDe; public ReduceInputFunction(SerDe<K> keySerDe, SerDe<V> valueSerDe) { this.keySerDe = keySerDe; this.valueSerDe = valueSerDe; } @Override public Pair<K, Iterable<V>> call(Tuple2<ByteArray, Iterable<byte[]>> kv) throws Exception { return Pair.of(keySerDe.fromBytes(kv._1().value), Iterables.transform(kv._2(), valueSerDe.fromBytesFunction())); } }