查看“︁Java:Lambda”︁的源代码

=Functional Interface=
functional interface – an interface with a single abstract method. The Java API has many one-method interfaces such as Runnable, Callable, Comparator, ActionListener and others. They can be implemented and instantiated using anonymous class syntax. 
=Labmda expression=
<source lang="java">
public interface Hello {
	public void sayHello(String who);
}

public interface Print<T> {
	public void print(T msg);
}

public static void main(String[] args) {
	Hello h = (String s) -> System.out.println(s);
	h.sayHello("Riguz");

	Print<Float> p = (f) -> {
		System.out.println(f);
		System.out.println("Labmda");
	};
	p.print(new Float(3.1415926f));

}
</source>
=Aggregate operations =
The following is a generic version of it that accepts, as a parameter, a collection that contains elements of any data type:
<source lang="java">
public static <X, Y> void processElements(
    Iterable<X> source,
    Predicate<X> tester,
    Function <X, Y> mapper,
    Consumer<Y> block) {
    for (X p : source) {
        if (tester.test(p)) {
            Y data = mapper.apply(p);
            block.accept(data);
        }
    }
}
</source>
The following example uses aggregate operations to print the e-mail addresses of those members contained in the collection roster who are eligible for Selective Service:
<source lang="java">
roster
    .stream()
    .filter(
        p -> p.getGender() == Person.Sex.MALE
            && p.getAge() >= 18
            && p.getAge() <= 25)
    .map(p -> p.getEmailAddress())
    .forEach(email -> System.out.println(email));
</source>
{| class="wikitable" border="1"
|-
! Aggregate Operation
|-
| Stream<E> stream()
|-
| Stream<T> filter(Predicate<? super T> predicate)
|-
| <R> Stream<R> map(Function<? super T,? extends R> mapper)
|-
| void forEach(Consumer<? super T> action)
|}
[[Category:Programe]]