判断某字符是否在限定的范围里

  方法一：

  String reg="NA|LA|EMEA|APAC|SA";
  System.out.println("EM".matches(reg));
  System.out.println("APAC".matches(reg));
  方法二：
  String[] val=new String[]{"NA","LA","EMEA","APAC","SA"};
  Arrays.sort(val);
  //[APAC, EMEA, LA, NA, SA]
  System.out.println(Arrays.toString(val));
  String s="SA";
  System.out.println(Arrays.binarySearch(val, s));