1 package org.robolectric.util; 2 3 import java.util.Objects; 4 5 /** 6 * Represents an operation that accepts a single input argument and returns no 7 * result. Unlike most other functional interfaces, {@code Consumer} is expected 8 * to operate via side-effects. 9 * 10 * Included in Robolectric since Android doesn't support streams yet (as of O). 11 * 12 * @param <T> the type of the input to the operation 13 */ 14 public interface Consumer<T> { 15 16 /** 17 * Performs this operation on the given argument. 18 * 19 * @param t the input argument 20 */ 21 void accept(T t); 22 23 /** 24 * Returns a composed {@code Consumer} that performs, in sequence, this operation followed by the 25 * {@code after} operation. If performing either operation throws an exception, it is relayed to 26 * the caller of the composed operation. If performing this operation throws an exception, the 27 * {@code after} operation will not be performed. 28 * 29 * @param after the operation to perform after this operation 30 * @return a composed {@code Consumer} that performs in sequence this operation followed by the 31 * {@code after} operation 32 * @throws NullPointerException if {@code after} is null 33 */ 34 default Consumer<T> andThen(Consumer<? super T> after) { 35 Objects.requireNonNull(after); 36 return (T t) -> { 37 accept(t); 38 after.accept(t); 39 }; 40 } 41 } 42
