[Ch10c] Bit of song pruning and genre maintenance (3d623cee) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch10c/JukeboxData.java

+29 −9

Changes for src/main/java/ch10c/JukeboxData.java: 29 added lines, 9 removed lines.
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		package ch10c;

		import java.util.List;
		import java.util.Map;
		import java.util.function.Function;
		import java.util.stream.Collectors;

		// Interesting points: "special" characters á, punctuation marks, multiple cover versions, BPM ranges (and maybe doubled/halved rates?)
		// TODO: introduce duplicates for number of times played
		// or: add a timesPlayed field.
		public class JukeboxData {
		class Songs {
		static class Songs {
		public List<Song> getSongs() {
		return List.of(
		new Song("Somersault", "Zero 7", 147, "New wave", 2004),
		new Song("$10", "Hitchhiker", 140, "Dance",2016),
		new Song("$10", "Hitchhiker", 140, "Electronic", 2016),
		new Song("Havana", "Camila Cabello", 105, "R&B", 2017),
		new Song("Cassidy", "Grateful Dead", 158, "Rock", 1972),
		new Song("50 ways", "Paul Simon", 102, "Soft Rock", 1975),
		new Song("If There's a Rocket Tie Me to It", "Snow Patrol", 140, "Soft Rock", 2009),
		new Song("Hurt", "Nine Inch Nails", 79, "Industrial Rock", 1995),
		new Song("Silence", "Delerium", 98, "Trance", 1999),
		new Song("Hurt", "Johnny Cash", 91, "Acoustic Rock", 2002),
		new Song("Hurt", "Johnny Cash", 91, "Soft Rock", 2002),
		new Song("Watercolour", "Pendulum", 174, "Electronic", 2010),
		new Song("The Outsider", "A Perfect Circle", 113, "Alternative Rock", 2004),
		new Song("With a Little Help from My Friends", "The Beatles", 112, "Rock", 1967),
		new Song("Come Together", "The Beatles", 92, "Blues rock", 1968),
		new Song("Take Five", "Brubeck", 174, "Jazz", 1959),
		new Song("Come Together", "The Smokin' Mojo Filters", 176, "Rock", 1995),
		new Song("With a Little Help from My Friends", "Joe Cocker", 72, "Soul", 1968),
		new Song("With a Little Help from My Friends", "Joe Cocker", 72, "Rock", 1968),
		new Song("Immigrant Song", "Karen O feat Trent Reznor and Atticus Ross", 120, "Industrial Rock", 2011),
		new Song("High Hopes", "Panic! at the Disco", 164, "Pop", 2018),
		new Song("Machine", "Imagine Dragons", 81, "Rock", 2018),
		new Song("Breathe", "The Prodigy", 130, "Electronic", 1996),
		new Song("What's Going On", "Gaye", 203, "R&B", 1971),
		new Song("Hallucinate", "Dua Lipa", 122, "Disco", 2020),
		new Song("Hallucinate", "Dua Lipa", 122, "Pop", 2020),
		new Song("Walk Me Home", "P!nk", 88, "Pop", 2019),
		new Song("I am not a woman, I'm a god", "Halsey", 180, "Alternative Rock", 2021),
		new Song("Pasos de cero", "Pablo Alborán", 99, "Latin", 2014),
		new Song("Nature's Kingdom", "Delerium", 85, "Trance", 2000),
		new Song("Smooth", "Santana", 116, "Rock", 1999),
		new Song("Smooth", "Santana", 116, "Latin", 1999),
		new Song("Immigrant song", "Led Zeppelin", 112, "Rock", 1970));
		}
		}

		public static void main(String[] args) {
		Songs songs = new Songs();
		List<Song> songList = songs.getSongs();

		// ORDER MATTERS
		List<String> genres = songList.stream().map(song -> song.getGenre())
		.distinct()
		.collect(Collectors.toList());
		System.out.println("genres = " + genres);

		System.out.println(songList.stream().map(song -> song.getGenre())
		.distinct()
		.count());

		Map<String, Long> genreCount = songList.stream().map(song -> song.getGenre())
		.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
		System.out.println("genreCount = " + genreCount);

		}

		}

src/main/java/ch10c/Song.java

+20 −0

Changes for src/main/java/ch10c/Song.java: 20 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -14,4 +14,24 @@ public class Song {
		this.genre = genre;
		this.year = year;
		}

		public String getTitle() {
		return title;
		}

		public String getArtist() {
		return artist;
		}

		public int getBpm() {
		return bpm;
		}

		public String getGenre() {
		return genre;
		}

		public int getYear() {
		return year;
		}
		}