meal2.java

来自「《Java编程思想》第四版源代码」· Java 代码 · 共 44 行

//: enumerated/menu/Meal2.java
package enumerated.menu;
import net.mindview.util.*;

public enum Meal2 {
  APPETIZER(Food.Appetizer.class),
  MAINCOURSE(Food.MainCourse.class),
  DESSERT(Food.Dessert.class),
  COFFEE(Food.Coffee.class);
  private Food[] values;
  private Meal2(Class<? extends Food> kind) {
    values = kind.getEnumConstants();
  }
  public interface Food {
    enum Appetizer implements Food {
      SALAD, SOUP, SPRING_ROLLS;
    }
    enum MainCourse implements Food {
      LASAGNE, BURRITO, PAD_THAI,
      LENTILS, HUMMOUS, VINDALOO;
    }
    enum Dessert implements Food {
      TIRAMISU, GELATO, BLACK_FOREST_CAKE,
      FRUIT, CREME_CARAMEL;
    }
    enum Coffee implements Food {
      BLACK_COFFEE, DECAF_COFFEE, ESPRESSO,
      LATTE, CAPPUCCINO, TEA, HERB_TEA;
    }
  }
  public Food randomSelection() {
    return Enums.random(values);
  }
  public static void main(String[] args) {
    for(int i = 0; i < 5; i++) {
      for(Meal2 meal : Meal2.values()) {
        Food food = meal.randomSelection();
        System.out.println(food);
      }
      System.out.println("---");
    }
  }
} /* Same output as Meal.java *///:~