code: public static int[] getKeys(int key) {
          int[] keys = {0, 1, 1};
          if (key > 0) {
              // 自定义算Key
              if (key < TEN) {
                  keys[0] = key;
                  keys[1] = key - key / 2;
                  keys[2] = Math.abs(keys[1] - key % keys[1]);
              } else if (key < HUNDRED) {
                  keys[0] = key % 10;
                  keys[1] = Math.abs(key / 10 - keys[0]) % 9 + 1;
                  keys[2] = keys[0] * keys[1] / (keys[0] + keys[1]) % 10;
              } else if (key < THOUSAND) {
                  int middle = key % 100 / 10;
                  keys[0] = key % 10;
                  keys[1] = key / 100;
                  keys[2] = ((int) (Math.pow(keys[1], keys[0]) / middle) % 9 + 1);
              } else {
                  int length = String.valueOf(key).length();
                  keys[0] = key % 10;
                  keys[1] = key / (int) Math.pow(10, length - 1);
                  length = (keys[0] + keys[1] + keys[0] * keys[1]) % (length - 2) + 2;
                  keys[2] = (int) (key % Math.pow(10, length) / Math.pow(10, length - 1));
              }
              keys[2] = keys[2] % 8 + 2;
          }
          return keys;
      }
docs: 通过获取一个KEY数组
  
  @param key 可自定义一个INT型数值
  
  @return 长度为3的KEY数组
  
  @deprecated 无用类