Java 8 examples

Java8Examples.java

package com.app1;

import java.time.Duration;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalTime;
import java.time.Month;
import java.time.Period;
import java.time.temporal.ChronoUnit;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

/**
 * @author aNNiMON
 */
public class Java8Examples {
    
    public static void main(String[] args) {
        /*new Thread(new Runnable() {
            public void run() {
                counter();
            }
        }).start();*/
        new Thread(Java8Examples::counter).start();
        
        listDemo();
        timeDemo();
    }
    
    private static void listDemo() {
        List<Integer> list = new ArrayList<>();
        final Random rnd = new Random();
        
        /*for (int i = 0; i < 20; i++) {
            list.add(rnd.nextInt(100));
        }*/
        rnd.ints(0, 100).limit(20).forEach(list::add);
        
        System.out.println("Sorted list");
        list.stream().sorted().forEach(p -> System.out.print(p + " "));
        System.out.println();
        
        int min = list.stream().min((Integer o1, Integer o2) -> o1.compareTo(o2)).get();
        System.out.println("Min: " + min);
        
        int max = list.stream().max((Integer o1, Integer o2) -> o1.compareTo(o2)).get();
        System.out.println("Max: " + max);
        
        int median = (max + min) / 2;
        System.out.println("List with values above " + median);
        list.stream().filter(p -> p >= median).forEach(p -> System.out.print(p + " "));
        System.out.println();
    }
    
    private static void timeDemo() {
        System.out.println();
        System.out.println(Instant.now());
        System.out.println(LocalTime.now());
        System.out.println(LocalDate.now().plus(5, ChronoUnit.WEEKS));
        
        LocalDate date2000 = LocalDate.of(2000, Month.JANUARY, 1);
        System.out.println(Period.between(LocalDate.now(), date2000));
        System.out.println();
    }
    
    private static void counter() {
        Instant now = Instant.now();
        int counter = 0;
        while (counter <= 10) {
            System.out.println(counter);
            counter++;
            try {
                Thread.sleep(500);
            } catch (InterruptedException ex) { }
        }
        System.out.println("Elapsed time: " + Duration.between(Instant.now(), now));
    }
    
    private static void multiplicationTable() {
        // Prints "4" "6"
        /*IntStream.range(1, 10)
                .flatMap(i -> IntStream.range(1, 10).map(j -> i * j))
                .forEach(System.out::println);*/

        // Prints "2 * 2 = 4" "2 * 3 = 6"
        IntStream.range(1, 10)
                .mapToObj(String::valueOf)
                .flatMap(i -> IntStream.range(1, 10)
                        .mapToObj(j -> String.format("%s * %d = %d", i, j, Integer.parseInt(i) * j) + (j == 9 ? "\n" : "")))
                .forEach(System.out::println);
    }
    
}