| /* |
| * 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.flink.api.common.functions; |
| |
| import org.apache.flink.annotation.Public; |
| |
| import java.io.Serializable; |
| |
| /** |
| * Interface for Cross functions. Cross functions are applied to the Cartesian product |
| * of their inputs and are called for each pair of elements. |
| * |
| * They are optional, a means of convenience that can be used to directly manipulate the |
| * pair of elements instead of producing 2-tuples containing the pairs. |
| * <p> |
| * The basic syntax for using Cross on two data sets is as follows: |
| * <pre>{@code |
| * DataSet<X> set1 = ...; |
| * DataSet<Y> set2 = ...; |
| * |
| * set1.cross(set2).with(new MyCrossFunction()); |
| * }</pre> |
| * <p> |
| * {@code set1} is here considered the first input, {@code set2} the second input. |
| * |
| * @param <IN1> The type of the elements in the first input. |
| * @param <IN2> The type of the elements in the second input. |
| * @param <OUT> The type of the result elements. |
| */ |
| @Public |
| public interface CrossFunction<IN1, IN2, OUT> extends Function, Serializable { |
| |
| /** |
| * Cross UDF method. Called once per pair of elements in the Cartesian product of the inputs. |
| * |
| * @param val1 Element from first input. |
| * @param val2 Element from the second input. |
| * @return The result element. |
| * |
| * @throws Exception The function may throw Exceptions, which will cause the program to cancel, |
| * and may trigger the recovery logic. |
| */ |
| OUT cross(IN1 val1, IN2 val2) throws Exception; |
| |
| } |