1 /* 2 * Copyright (c) 2010, 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 * An operation which accepts a single input argument and returns no result. 31 * Unlike most other functional interfaces, {@code Consumer} is expected to 32 * operate via side-effects. 33 * 34 * @param <T> The type of input objects to {@code accept} 35 * 36 * @since 1.8 37 */ 38 @FunctionalInterface 39 public interface Consumer<T> { 40 41 /** 42 * Accept an input value. 43 * 44 * @param t the input object 45 */ 46 void accept(T t); 47 48 /** 49 * Returns a Consumer which performs in sequence the {@code apply} methods 50 * of multiple Consumers. This Consumer's {@code accept} method is performed 51 * followed by the {@code accept} method of the specified Consumer operation. 52 * 53 * @param other an additional Consumer which will be chained after this 54 * Consumer 55 * @return a Consumer which performs in sequence the {@code accept} method 56 * of this Consumer and the {@code accept} method of the specified Consumer 57 * operation 58 * @throws NullPointerException if other is null 59 */ 60 default Consumer<T> chain(Consumer<? super T> other) { 61 Objects.requireNonNull(other); 62 return (T t) -> { accept(t); other.accept(t); }; 63 } 64 }