BiConsumer.java revision e053d5ee5eea301559822c98e69874344c971502 
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25package java.util.function;
26
27import 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 * @hide 1.8
44 */
45@FunctionalInterface
46public interface BiConsumer<T, U> {
47
48    /**
49     * Performs this operation on the given arguments.
50     *
51     * @param t the first input argument
52     * @param u the second input argument
53     */
54    void accept(T t, U u);
55
56    /**
57     * Returns a composed {@code BiConsumer} that performs, in sequence, this
58     * operation followed by the {@code after} operation. If performing either
59     * operation throws an exception, it is relayed to the caller of the
60     * composed operation.  If performing this operation throws an exception,
61     * the {@code after} operation will not be performed.
62     *
63     * @param after the operation to perform after this operation
64     * @return a composed {@code BiConsumer} that performs in sequence this
65     * operation followed by the {@code after} operation
66     * @throws NullPointerException if {@code after} is null
67     */
68    default BiConsumer<T, U> andThen(BiConsumer<? super T, ? super U> after) {
69        Objects.requireNonNull(after);
70
71        return (l, r) -> {
72            accept(l, r);
73            after.accept(l, r);
74        };
75    }
76}
77