Java 8 Lambdas

Java8Lambdas.java

import java.util.Arrays;
import java.util.Comparator;
import java.util.function.Consumer;
import java.util.function.Supplier;

public class Main {

    private static void sort(String[] strings, Comparator comp) {
        Arrays.sort(strings, comp);
    }

    @FunctionalInterface
    interface Action {
        void perform();
    }

    static class Action2<T> implements Consumer<T> {

        @Override
        public void accept(T t) {
            System.out.println(this + ".accept: " + t);
        }

    }

    private static <T> void doSomething(Supplier<T> function, Consumer<T> onOk, Runnable onError) {
        T ret = function.get();
        if (null != ret) {
            onOk.accept(ret);
        } else {
            onError.run();
        }
    }

    public static void main(String[] args) {
        final String[] strings = {"a", "z", "b"};
        Arrays.stream(strings).forEach(System.out::println);
        final Comparator<String> comparator = (String a, String b) -> a.compareTo(b);
        sort(strings, comparator);
        Arrays.stream(strings).forEach(System.out::println);

        Action2<Integer> action2 = new Action2<>();
        doSomething(
                () -> 1 + 1,
                //(x) -> System.out.println("ok: " + x),
                //action2::accept, // (x) -> action2.accept(x),
                (x) -> doSomething(() -> 2 + x, null, null),
                () -> System.out.println("error")
        );

    }

}