11.5. Operations

public class TVShow {
   String name;
   String category;
   int rating;
   int year;

   public TVShow(String name, int year, String category, int rating) {
      this.name = name;
      this.year = year;
      this.category = category;
      this.rating = rating;
   }

   public String getQualifiedName(){
      return String.format("%s (%d)", name, year);
   }

   @Override
   public String toString() {
      return String.format("%-25s  Category: %-6s   Rating: %s", getQualifiedName(), category, rating);
   }

   // getters and setters
}

public class ProcessingShows {

   public static void main(String[] args) {
      TVShow[] shows = {
              new TVShow("Rick and Morty", 2013, "Comedy", 100),
              new TVShow("Game of Thrones", 2011, "Drama", 92),
              new TVShow("Stranger Things", 2016, "Terror", 90),
              new TVShow("Friends", 1994, "Comedy", 99),
              new TVShow("House of Cards", 2013, "Drama", 85),
              new TVShow("The Walking Dead", 2010, "Terror", 78),
              new TVShow("The Good Place", 2016, "Comedy", 86),
      };

      List<TVShow> list = Arrays.asList(shows);

      // Displays all shows
      System.out.printf("TV shows:%n");
      list.stream().forEach(System.out::println);

      // Predicate that returns true for ratings greater than 90
      Predicate<TVShow> highRatings = tvShow -> tvShow.getRating() > 90;

      // Displays only shows rated over 90 sorted by rating (ascending)
      System.out.printf("%nShows rated over 90:%n");
      list.stream()
              .filter(highRatings)
              .sorted(Comparator.comparing(TVShow::getRating))
              .forEach(System.out::println);

      // Displays a show rated over 90
      System.out.printf("%nA show rated over 90:%n%s",
              list.stream()
                      .filter(highRatings)
                      .findAny()
                      .get());
   }
}

TV shows:
Rick and Morty (2013)      Category: Comedy   Rating: 100
Game of Thrones (2011)     Category: Drama    Rating: 92
Stranger Things (2016)     Category: Terror   Rating: 90
Friends (1994)             Category: Comedy   Rating: 99
House of Cards (2013)      Category: Drama    Rating: 85
The Walking Dead (2010)    Category: Terror   Rating: 78
The Good Place (2016)      Category: Comedy   Rating: 86

Shows rated over 90:
Game of Thrones (2011)     Category: Drama    Rating: 92
Friends (1994)             Category: Comedy   Rating: 99
Rick and Morty (2013)      Category: Comedy   Rating: 100

A show rated over 90:
Rick and Morty (2013)      Category: Comedy   Rating: 100

Function<TVShow, String> byCategory = TVShow::getCategory;
Function<TVShow, Integer> byRating = TVShow::getRating;

Comparator<TVShow> categoryThenRating =
        Comparator.comparing(byCategory).thenComparing(byRating);

System.out.printf("%nShows in ascending order by category and then rating: %n");
list.stream()
        .sorted(categoryThenRating)
        .forEach(System.out::println);

System.out.printf("%nShows in descending order by category and then rating: %n");
list.stream()
        .sorted(categoryThenRating.reversed())
        .forEach(System.out::println);

Shows in ascending order by category and then rating: 
The Good Place (2016)      Category: Comedy   Rating: 86
Friends (1994)             Category: Comedy   Rating: 99
Rick and Morty (2013)      Category: Comedy   Rating: 100
House of Cards (2013)      Category: Drama    Rating: 85
Game of Thrones (2011)     Category: Drama    Rating: 92
The Walking Dead (2010)    Category: Terror   Rating: 78
Stranger Things (2016)     Category: Terror   Rating: 90

Shows in descending order by category and then rating: 
Stranger Things (2016)     Category: Terror   Rating: 90
The Walking Dead (2010)    Category: Terror   Rating: 78
Game of Thrones (2011)     Category: Drama    Rating: 92
House of Cards (2013)      Category: Drama    Rating: 85
Rick and Morty (2013)      Category: Comedy   Rating: 100
Friends (1994)             Category: Comedy   Rating: 99
The Good Place (2016)      Category: Comedy   Rating: 86

System.out.printf("%nUnique categories in ascending order: %n");
list.stream()
        .map(TVShow::getCategory)
        .distinct()
        .sorted()
        .forEach(System.out::println);

System.out.printf("%nDisplay title and year, but sorted by rating: %n");
list.stream()
        .sorted(Comparator.comparing(TVShow::getRating).reversed())
        .map(TVShow::getQualifiedName)
        .forEach(System.out::println);

Unique categories in ascending order: 
Comedy
Drama
Terror

Display title and year, but sorted by rating: 
Rick and Morty (2013)
Friends (1994)
Game of Thrones (2011)
Stranger Things (2016)
The Good Place (2016)
House of Cards (2013)
The Walking Dead (2010)

System.out.printf("%nShows grouped by category:%n");
Map<String, List<TVShow>> map = list.stream()
        .collect(Collectors.groupingBy(TVShow::getCategory));

map.forEach((category, tvShows) -> {
    System.out.printf(
            "%s: %s%n",
            category,
            tvShows.stream()
                    .map(TVShow::getQualifiedName)
                    .collect(Collectors.joining(", ", "", ""))
    );
});

Shows grouped by category:
Drama: Game of Thrones (2011), House of Cards (2013)
Comedy: Rick and Morty (2013), Friends (1994), The Good Place (2016)
Terror: Stranger Things (2016), The Walking Dead (2010)

System.out.printf("%nCount shows per category:%n");
Map<String, Long> showCountByCategory = list.stream()
        .collect(Collectors.groupingBy(TVShow::getCategory, TreeMap::new, Collectors.counting()));

showCountByCategory.forEach((category, count) -> {
    System.out.printf("%s: %d%n", category, count);
});

Count shows per category:
Comedy: 3
Drama: 2
Terror: 2

System.out.printf(
        "%nAverage show rating: %.2f%n",
        list.stream()
                .mapToInt(TVShow::getRating)
                .average()
                .orElse(0)
);

System.out.printf(
        "%nSum of show ratings: %d of %d",
        list.stream()
                .mapToInt(TVShow::getRating)
                .reduce(0, (aggregated, value) -> aggregated + value),
        list.size() * 100
);

Average show rating: 90,00

Sum of show ratings: 630 of 700