位元組編碼轉換

把 ASCII 字元的字串轉換為十六進位制值

public static String bin2hex(String bin) {
    char[] digital = "0123456789ABCDEF".toCharArray();
    StringBuffer sb = new StringBuffer("");
    byte[] bs = bin.getBytes();

    for (int i = 0; i < bs.length; i++) {
        int bit = (bs[i] & 0xF0) >> 4;
        sb.append(digital[bit]);
        bit = bs[i] & 0xF;
        sb.append(digital[bit]);
    }
    return sb.toString();
}

把十六進位制值字串轉化為 ASCII 字元

public static String hex2bin(String hex) {
    String digital = "0123456789ABCDEF";
    char[] hex2char = hex.toCharArray();
    byte[] bytes = new byte[hex.length() / 2];

    for (int i = 0; i < bytes.length; i++) {
        int temp = digital.indexOf(hex2char[(2 * i)]) * 16;
        temp += digital.indexOf(hex2char[(2 * i + 1)]);
        bytes[i] = ((byte) (temp & 0xFF));
    }
    return new String(bytes);
}

位元組轉16進位制字串

    public static String byte2hex(byte[] b) {
        String hs = "";
        String tmp = "";
        for (int n = 0; n < b.length; n++) {
            tmp = Integer.toHexString(b[n] & 0xFF);
            if (tmp.length() == 1)
                hs = hs + "0" + tmp;
            else {
                hs = hs + tmp;
            }
        }
        tmp = null;
        return hs.toUpperCase();
    }

16進位制轉位元組

public static byte[] hex2byte(byte[] b) {
        if (b.length % 2 != 0) {
            throw new IllegalArgumentException("長度不是偶數");
        }
        byte[] b2 = new byte[b.length / 2];
        for (int n = 0; n < b.length; n += 2) {
            String item = new String(b, n, 2);

            b2[(n / 2)] = ((byte) Integer.parseInt(item, 16));
        }
        b = (byte[]) null;
        return b2;
    }

持續更新中。。