1 package cn.itcast.p10.map.test;

 2

 3 import java.util.HashMap;

 4 import java.util.Map;

 5

 6 public class MapTest2 {

 7

 8     public static void main(String[] args) {

 9         // TODO Auto-generated method stub

10         /*

11          * Map在有映射关系时，可以优先考虑。

12          *

13          * 在查表法中的应用较为多见。

14          */

15         String week = getWeek(1);

16         System.out.println(week);

17

18         System.out.println(getWeekByMap(week));

19     }

20

21     public static String getWeekByMap(String week) {

22         Map<String,String> map = new HashMap<String,String>();

23

24         map.put("星期一", "Mon");

25         map.put("星期二", "Tus");

26         map.put("星期三", "Wes");

27         map.put("星期日", "Sun");

28         map.put("星期天", "Sun");

29

30         //map.put("预热班", "张三");

31         //map.put("预热班", "李四");键唯一会覆盖

32         //map.put("预热班", "王五");

33                   //以上可以map.put("预热班",Set<Student>);可以把value放在集合里

34         return map.get(week);

35

36

37     }

38

39     public static String getWeek(int week) {

40

41         if (week<1 || week>7) {

42             throw new RuntimeException("没有对应的星期，请您重新输出");

43         }

44         String[] weeks = {"","星期一","星期二"};

45

46         return weeks[week];

47     }

48

49 }