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.fn; import org.apache.crunch.CrunchRuntimeException; import org.apache.crunch.Emitter; import org.apache.crunch.Pair; import org.apache.spark.api.java.function.PairFlatMapFunction; import scala.Tuple2; /** * A Crunch-compatible abstract base class for Spark's {@link PairFlatMapFunction}. Subclasses * of this class may be used against either Crunch {@code PCollections} or Spark {@code RDDs}. */ public abstract class SPairFlatMapFunction<T, K, V> extends SparkDoFn<T, Pair<K, V>> implements PairFlatMapFunction<T, K, V> { @Override public void process(T input, Emitter<Pair<K, V>> emitter) { try { for (Tuple2<K, V> kv : call(input)) { emitter.emit(Pair.of(kv._1(), kv._2())); } } catch (Exception e) { throw new CrunchRuntimeException(e); } } }