Album.java

package org.dhbw.ai.fp.album;

import org.dhbw.ai.fp.album.model.Album;
import org.dhbw.ai.fp.album.model.Track;
import org.dhbw.ai.fp.album.persistence.CsvFileDataLoader;
import org.dhbw.ai.fp.optional.WithOptional;

import java.time.temporal.TemporalField;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.function.IntPredicate;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.stream.Stream;

/**
 * Album Main Application.
 *
 */
public class AlbumApp
{
	public static void main(String[] args) throws Exception
	{
		final var albums = CsvFileDataLoader.loadData();
		System.out.println("Found [" + albums.size() + "] Albums.");
		//albums.stream().map(album -> "\t" + album).sorted().forEach(System.out::println);

        // Gather the pairs for the numbers between 1 and 10 and their square.

        IntStream
                .range(0, 100)
                .boxed()
                .map(v -> Integer.valueOf(v) + " " + Math.pow(v, 2))
                .forEach(System.out::println);


        IntPredicate predicate = x -> x % 2 == 0;
        int lel = IntStream.range(0, 100).filter(predicate).reduce(0, (left, right) -> left + right);
        System.out.println(lel);


        int totalTracks = albums.stream()
                .map(album -> album.getTracks().size())
                .reduce(0, (left, right) -> left + right);
        System.out.println(totalTracks);

        System.out.println("Distinct Artists:\n");
        albums.stream()
                .flatMap(album -> album.getTracks().stream())
                .flatMap(track -> track.getArtist().stream())
                .distinct()
                .forEach(System.out::println);


        Map<Integer, List<Album>> map = albums.stream()
                .collect(Collectors.groupingBy(album -> album.getReleaseDate().getYear() / 10 * 10));

        System.out.println(map);

        Map<String, List<Album>> map3 = albums.stream()
                .collect(Collectors.groupingBy(o -> {
                    if (o.getTracks().size() <= 10) {
                        return "Short";
                    } else {
                        return "Long";
                    }
                }));

        System.out.println(map3);


        Map<Boolean, List<Album>> partition0 = albums.stream()
                .collect(Collectors.partitioningBy(album -> album.getReleaseDate().getYear() <= 2000));
        System.out.println(partition0);
	}
}