DoubleConsumer.java revision c514380e14eafe28505ee3c8ccf0f64951a73965 
1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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7 * published by the Free Software Foundation.  Oracle designates this
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14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
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24 */
25package java.util.function;
26
27import java.util.Objects;
28
29/**
30 * Represents an operation that accepts a single {@code double}-valued argument and
31 * returns no result.  This is the primitive type specialization of
32 * {@link Consumer} for {@code double}.  Unlike most other functional interfaces,
33 * {@code DoubleConsumer} is expected 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(double)}.
37 *
38 * @see Consumer
39 * @since 1.8
40 */
41@FunctionalInterface
42public interface DoubleConsumer {
43
44    /**
45     * Performs this operation on the given argument.
46     *
47     * @param value the input argument
48     */
49    void accept(double value);
50
51    /**
52     * Returns a composed {@code DoubleConsumer} that performs, in sequence, this
53     * operation followed by the {@code after} operation. If performing either
54     * operation throws an exception, it is relayed to the caller of the
55     * composed operation.  If performing this operation throws an exception,
56     * the {@code after} operation will not be performed.
57     *
58     * @param after the operation to perform after this operation
59     * @return a composed {@code DoubleConsumer} that performs in sequence this
60     * operation followed by the {@code after} operation
61     * @throws NullPointerException if {@code after} is null
62     */
63    default DoubleConsumer andThen(DoubleConsumer after) {
64        Objects.requireNonNull(after);
65        return (double t) -> { accept(t); after.accept(t); };
66    }
67}
68