Java tutorial
/* * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.util.function; import java.util.Objects; /** * Represents an operation that accepts a single {@code double}-valued argument and * returns no result. This is the primitive type specialization of * {@link Consumer} for {@code double}. Unlike most other functional interfaces, * {@code DoubleConsumer} is expected to operate via side-effects. * * <p>This is a <a href="package-summary.html">functional interface</a> * whose functional method is {@link #accept(double)}. * * @see Consumer * @since 1.8 */ @FunctionalInterface public interface DoubleConsumer { /** * Performs this operation on the given argument. * * @param value the input argument */ void accept(double value); /** * Returns a composed {@code DoubleConsumer} that performs, in sequence, this * operation followed by the {@code after} operation. If performing either * operation throws an exception, it is relayed to the caller of the * composed operation. If performing this operation throws an exception, * the {@code after} operation will not be performed. * * @param after the operation to perform after this operation * @return a composed {@code DoubleConsumer} that performs in sequence this * operation followed by the {@code after} operation * @throws NullPointerException if {@code after} is null */ default DoubleConsumer andThen(DoubleConsumer after) { Objects.requireNonNull(after); return (double t) -> { accept(t); after.accept(t); }; } }