Java8-Lambda-No.03

import java.util.Comparator;import java.util.Objects;import java.util.UUID;import java.util.concurrent.Callable;import java.util.function.Consumer;import java.util.function.Function;import java.util.function.Predicate;import java.util.function.Supplier;public class Lambda3 {    @FunctionalInterface    interface Fun {        void foo();    }    public static void main(String[] args) throws Exception {        // Predicates        Predicate<String> predicate = (s) -> s.length() > 0;        predicate.test("foo");              // true        predicate.negate().test("foo");     // false        Predicate<Boolean> nonNull = Objects::nonNull;        Predicate<Boolean> isNull = Objects::isNull;        Predicate<String> isEmpty = String::isEmpty;        Predicate<String> isNotEmpty = isEmpty.negate();        // Functions        Function<String, Integer> toInteger = Integer::valueOf;        Function<String, String> backToString = toInteger.andThen(String::valueOf);        backToString.apply("123");     // "123"        // Suppliers        Supplier<Person> personSupplier = Person::new;        personSupplier.get();   // new Person        // Consumers        Consumer<Person> greeter = (p) -> System.out.println("Hello, " + p.firstName);        greeter.accept(new Person("Luke", "Skywalker"));        // Comparators        Comparator<Person> comparator = (p1, p2) -> p1.firstName.compareTo(p2.firstName);        Person p1 = new Person("John", "Doe");        Person p2 = new Person("Alice", "Wonderland");        comparator.compare(p1, p2);             // > 0        comparator.reversed().compare(p1, p2);  // < 0        // Runnables        Runnable runnable = () -> System.out.println(UUID.randomUUID());        runnable.run();        // Callables        Callable<UUID> callable = UUID::randomUUID;        callable.call();    }}