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 org.apache.crunch.DoFn; import org.apache.crunch.Pair; import org.apache.crunch.impl.spark.GuavaUtils; import org.apache.crunch.impl.spark.SparkRuntimeContext; import org.apache.spark.api.java.function.PairFlatMapFunction; import scala.Tuple2; import java.util.Iterator; public class PairFlatMapDoFn<T, K, V> implements PairFlatMapFunction<Iterator<T>, K, V> { private final DoFn<T, Pair<K, V>> fn; private final SparkRuntimeContext ctxt; public PairFlatMapDoFn(DoFn<T, Pair<K, V>> fn, SparkRuntimeContext ctxt) { this.fn = fn; this.ctxt = ctxt; } @Override public Iterable<Tuple2<K, V>> call(Iterator<T> input) throws Exception { ctxt.initialize(fn, null); return Iterables.transform(new CrunchIterable<T, Pair<K, V>>(fn, input), GuavaUtils.<K, V>pair2tupleFunc()); } }