case 5:
                System.out.println("**************积分抽奖**************");while(true) {
                    System.out.println("请选择 1.抽奖 2.退出");
                    int choose2 = input.nextInt();
                    switch (choose2) {
                    case 1:
                        String lottery = userDao.lottery(loginAccount);
                        System.out.println(lottery);
                        break;
                    case 2:
                        break;
                    default:
                        System.out.println("输入有误");
                        break;
                    }
                }

switch中的break只能终止switch循环,无法终止while循环,如果将break改成return,虽然能终止循环,但是会用力过猛,将整个方法都终止,如何做到精准的终止掉当前while循环,我们可以在外面定义一个boolean变量flag来控制while循环,在case中,通过改变flag的值来控制while循环.

 1 case 5:
 2                 System.out.println("**************积分抽奖**************");
 3                 boolean flag = true;
 4                 while(flag) {
 5                     System.out.println("请选择 1.抽奖 2.退出");
 6                     int choose2 = input.nextInt();
 7                     switch (choose2) {
 8                     case 1:
 9                         String lottery = userDao.lottery(loginAccount);
10                         System.out.println(lottery);
11                         break;
12                     case 2:
13                         flag = false;
14                         break;
15                     default:
16                         System.out.println("输入有误");
17                         break;
18                     }
19                 }