1 /* 2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.util.function; 26 27 import java.util.Objects; 28 29 /** 30 * Represents an operation that accepts two input arguments and returns no 31 * result. This is the two-arity specialization of {@link Consumer}. 32 * Unlike most other functional interfaces, {@code BiConsumer} is expected 33 * to operate via side-effects. 34 * 35 * <p>This is a <a href="package-summary.html">functional interface</a> 36 * whose functional method is {@link #accept(Object, Object)}. 37 * 38 * @param <T> the type of the first argument to the operation 39 * @param <U> the type of the second argument to the operation 40 * 41 * @see Consumer 42 * @since 1.8 43 */ 44 @FunctionalInterface 45 public interface BiConsumer<T, U> { 46 47 /** 48 * Performs this operation on the given arguments. 49 * 50 * @param t the first input argument 51 * @param u the second input argument 52 */ accept(T t, U u)53 void accept(T t, U u); 54 55 /** 56 * Returns a composed {@code BiConsumer} that performs, in sequence, this 57 * operation followed by the {@code after} operation. If performing either 58 * operation throws an exception, it is relayed to the caller of the 59 * composed operation. If performing this operation throws an exception, 60 * the {@code after} operation will not be performed. 61 * 62 * @param after the operation to perform after this operation 63 * @return a composed {@code BiConsumer} that performs in sequence this 64 * operation followed by the {@code after} operation 65 * @throws NullPointerException if {@code after} is null 66 */ andThen(BiConsumer<? super T, ? super U> after)67 default BiConsumer<T, U> andThen(BiConsumer<? super T, ? super U> after) { 68 Objects.requireNonNull(after); 69 70 return (l, r) -> { 71 accept(l, r); 72 after.accept(l, r); 73 }; 74 } 75 } 76