An exception of type NumberFormatException is thrown if any of the following situations occurs:
The first argument is null or is a string of length zero.
The radix is either smaller than Character.MIN_RADIX or larger than Character.MAX_RADIX.
Any character of the string is not a digit of the specified radix, except that the first character may be a minus sign '-' ('\u002D') or plus sign '+' ('\u002B') provided that the string is longer than length 1.
The value represented by the string is not a value of type int.
参考API Specification,看看是不是以下情况。
或者说
Integer.MAX_VALUE是2147483647,Integer.parseInt会将字符串解析为有符号整型,但如果要转比如F0F0F0F0,超出范围就没得搞。