Java Stream How to - Group and map to enum for each group total

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The following code shows how to group and map to enum for each group total.

Example

import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
/*w  w  w  .ja  v  a2 s  .  c  om*/
public class Main {
  public static void main(String...args){
    Map<Type, Set<CaloricLevel>> o =  
    Food.menu.stream().collect(
        Collectors.groupingBy(Food::getType, Collectors.mapping(
            dish -> { 
              if (dish.getCalories() <= 400) 
                   return CaloricLevel.DIET;
              else if (dish.getCalories() <= 700) 
                   return CaloricLevel.NORMAL;
              else 
                   return CaloricLevel.FAT; },
            Collectors.toSet() )));
    
    System.out.println(o);
    
  }
}
enum CaloricLevel { DIET, NORMAL, FAT }
enum Type { MEAT, FISH, OTHER }
class Food {

  private final String name;
  private final boolean vegetarian;
  private final int calories;
  private final Type type;

  public Food(String name, boolean vegetarian, int calories, Type type) {
      this.name = name;
      this.vegetarian = vegetarian;
      this.calories = calories;
      this.type = type;
  }

  public String getName() {
      return name;
  }

  public boolean isVegetarian() {
      return vegetarian;
  }

  public int getCalories() {
      return calories;
  }

  public Type getType() {
      return type;
  }
  @Override
  public String toString() {
      return name;
  }

  public static final List<Food> menu =
          Arrays.asList( new Food("pork", false, 1800, Type.MEAT),
                         new Food("beef", false, 7100, Type.MEAT),
                         new Food("chicken", false, 1400, Type.MEAT),
                         new Food("french fries", true, 1530, Type.OTHER),
                         new Food("rice", true, 3510, Type.OTHER),
                         new Food("season fruit", true, 1120, Type.OTHER),
                         new Food("pizza", true, 5150, Type.OTHER),
                         new Food("prawns", false, 1400, Type.FISH),
                         new Food("salmon", false, 4150, Type.FISH));
}

The code above generates the following result.

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