java 中 long 类型越界的处理

 

    public static String longToUnsigned(long signed) {
        if (signed < 0L) {
            BigInteger unsigned = BigInteger.valueOf(signed & Long.MAX_VALUE);
            return unsigned.setBit(63).toString();
        }
        return Long.toString(signed);
    }

    public static void main(String[] args) {
        long v = Long.MAX_VALUE + 1000L;
        System.out.println(Long.MAX_VALUE);
        System.out.println(v);
        System.out.println(longToUnsigned(v));
    }