简单了解enum

public enum Spiciness {
    // 枚举类型的实例是常量，按照惯例使用大写命名
    NOT, MILD, MEDIUM, HOT, FLAMING
}

/*
 * enum关键字为enum生成对应的类时，产生某些编译器行为，因此在很大程度上可以把enum
 * 当做其他任何类来处理
 */
public class Burrito {
    Spiciness degree;
    
    public Burrito(Spiciness degree){
        this.degree = degree;
    }
    
    public void describe(){
        System.out.print("This burrito is ");
        switch(degree){
            case NOT:    System.out.println("not spicy at all");
                        break;
            case MILD:    System.out.println("a little hot");
                        break;
            case HOT:
            case FLAMING:
            default:    System.out.println("maybe too hot");
                        break;
        }
    }
    
    public static void main(String[] args) {
        Burrito plain = new Burrito(Spiciness.NOT),
                greenChile = new Burrito(Spiciness.MEDIUM),
                jalapeno = new Burrito(Spiciness.HOT);
        plain.describe();
        greenChile.describe();
        jalapeno.describe();
    }
}
/*output:
This burrito is not spicy at all
This burrito is maybe too hot
This burrito is maybe too hot
*/