Java.util.EnumMap 示例，java.util.enummap,JavaEnumMapE

Java.util.EnumMap 示例，java.util.enummap,JavaEnumMapE

JavaEnumMapExample.javapackage com.jcg.example;import java.util.EnumMap;import java.util.Map;/** *  * @author anirudh * */public class JavaEnumMapExample {    public enum MealType{        BREAKFAST,LUNCH,SNACK,DINNER    }    public static void main(String[] args) {        Map myMealMap = new EnumMap(MealType.class);                //populate the map        myMealMap.put(MealType.BREAKFAST,"Enjoy Milk and Eggs for breakfast!");        myMealMap.put(MealType.LUNCH,"Enjoy Chicken, Rice and bread for Lunch!");        myMealMap.put(MealType.SNACK,"How about an apple for the evening snack!");        myMealMap.put(MealType.DINNER,"Keep the dinner light, lets have some salad!");        System.out.println("Welcome to meal planner, we have suggestions for following meals : ");        //print all the keys of enum map in sorted order        System.out.println(myMealMap.keySet());        //We can get the value from enumType        System.out.println(" Q: What should I have for lunch? ");        System.out.println(" A: "+myMealMap.get(MealType.LUNCH));        System.out.println(" Q: What should I have for snack? ");        System.out.println(" A: "+myMealMap.get(MealType.SNACK));        System.out.println(" Q: What should I have for dinner? ");        System.out.println(" A: "+myMealMap.get(MealType.DINNER));        //Iterate over enumMap        for (MealType mealType : myMealMap.keySet()) {            System.out.println(myMealMap.get(mealType));        }        System.out.println("*** Checking for concurrent modification exception! ***");        //Does not throw Concurrent modification Exception in enumMap        for (MealType mealType : myMealMap.keySet()) {            if(MealType.SNACK.equals(mealType)){                myMealMap.remove(MealType.SNACK);            }        }        //map changed without throwing Concurrent modification Exception        System.out.println(myMealMap);          }}

Output:Welcome to meal planner, we have suggestions for following meals : [BREAKFAST, LUNCH, SNACK, DINNER] Q: What should I have for lunch?  A: Enjoy Chicken, Rice and bread for Lunch! Q: What should I have for snack?  A: How about an apple for the evening snack! Q: What should I have for dinner?  A: Keep the dinner light, lets have some salad!Enjoy Milk and Eggs for breakfast!Enjoy Chicken, Rice and bread for Lunch!How about an apple for the evening snack!Keep the dinner light, lets have some salad!*** Checking for concurrent modification exception! ***{BREAKFAST=Enjoy Milk and Eggs for breakfast!, LUNCH=Enjoy Chicken, Rice and bread for Lunch!, DINNER=Keep the dinner light, lets have some salad!}