Consumer Example in Java 8
forEach in Iterable.java interface which uses Consumer:
default void forEach(Consumer<? super T> action)
{
Objects.requireNonNull(action);
for (T t : this) {
action.accept(t);
}
}
@FunctionalInterface public interface Consumer<T>
Consumer
is expected to operate via side-effects.This is a functional interface whose functional method is accept(Object)
.
Method:
void accept(T t)
andThen
default Consumer<T> andThen(Consumer<? super T> after)
Returns a composedConsumer
that performs, in sequence, this operation followed by theafter
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, theafter
operation will not be performed.- Parameters:
after
- the operation to perform after this operation- Returns:
- a composed
Consumer
that performs in sequence this operation followed by theafter
operation - Throws:
NullPointerException
- ifafter
is null
Example:
import java.util.Arrays;
import java.util.List;
import java.util.function.Consumer;
public class ConsumerEx {
public static void main(String[] args) {
List<String> list = Arrays.asList("india", "uk", "fiji");
Consumer<String> consumer = (t) -> {
System.out.println(t.toUpperCase());
};
list.forEach(consumer);
}
}
Output:
INDIA
UK
FIJI