Java8---Consumer

概述

/**
 * Represents an operation that accepts a single input argument and returns no
 * result. Unlike most other functional interfaces, {@code Consumer} 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(Object)}.
 *
 * @param <T> the type of the input to the operation
 *
 * @since 1.8
 */
@FunctionalInterface
public interface Consumer<T> {
 
    /**
     * Performs this operation on the given argument.
     *
     * @param t the input argument
     */
    void accept(T t);
 
    /**
     * Returns a composed {@code Consumer} 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 Consumer} that performs in sequence this
     * operation followed by the {@code after} operation
     * @throws NullPointerException if {@code after} is null
     */
    default Consumer<T> andThen(Consumer<? super T> after) {
        Objects.requireNonNull(after);
        return (T t) -> { accept(t); after.accept(t); };
    }
}

　　接收一个参数，没有返回结果；

应用

public class ConsumerTest {
 
    public static void main(String[] args) {
 
        List<Person> personList = new ArrayList<>();
 
        Consumer<Person> consumer = p -> {
            if (p.getName().equalsIgnoreCase("rose")){
                personList.add(p);
            }
        };
 
 
        Person person = new Person();
        person.setName("rose");
 
        consumer.accept(person);
 
        System.out.println(personList);
 
    }
 
 
    @Data
    private static class Person{
        private String name;
    }
 
}