如何将负十六进制值转换为字符串和字节数组

Question

I want to convert decimal -10 value to hex in a String and byte array format.

I have tried

String minHex = Integer.toHexString(Integer.valueOf(-10));
System.out.println(minHex);

Which results in fffffff6 , and I think it is not correct. And for converting byte array I am using below function which I found from

Convert a string representation of a hex dump to a byte array using Java?

public static byte[] hexStringToByteArray(String s) {
        int len = s.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
                                 + Character.digit(s.charAt(i+1), 16));
        }
        return data;
}

So also not sure it will work for minus hex value or not.

Answer 1

To convert an hex to a String the way you expect it ie -10 is converted to -a , use:

String hex = Integer.toString(-10, 16);

To convert to a byte array, simply convert the int to a byte array, it is represented the same way:

byte[] bytes = ByteBuffer.allocate(4).putInt(-10).array();