方式一：
Java代码
- /**
- * Convert hex string to byte[]
- * @param hexString the hex string
- * @return byte[]
- */
- public static byte[] hexStringToBytes(String hexString) {
- if (hexString == null || hexString.equals("")) {
- return null;
- }
- if(hexString.length()%2!=0){
- throw new RuntimeException("Hex bit string length must be even");
- }
- hexString = hexString.toUpperCase();
- int length = hexString.length() / 2;
- char[] hexChars = hexString.toCharArray();
- byte[] d = new byte[length];
- for (int i = 0; i < length; i++) {
- int pos = i * 2;
- d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
- }
- return d;
- }
- /**
- * Convert char to byte
- * 'F'-->15
- * @param c
- * char
- * @return byte
- */
- private static byte charToByte(char c) {
- int index = "0123456789ABCDEF".indexOf(c);
- if (index == -1) {
- index = "0123456789abcdef".indexOf(c);
- }
- return (byte) index;
- }
方式二：
Java代码
- // 从十六进制字符串到字节数组转换
- public static byte[] hexString2Bytes(String hexstr) {
- int length=hexstr.length();
- if(length%2!=0){
- throw new RuntimeException("Hex bit string length must be even");
- }
- byte[] b = new byte[hexstr.length() / 2];
- int j = 0;
- for (int i = 0; i < b.length; i++) {
- char c0 = hexstr.charAt(j++);
- char c1 = hexstr.charAt(j++);
- b[i] = (byte) ((parse(c0) << 4) | parse(c1));
- }
- return b;
- }
- private static int parse(char c) {
- if (c >= 'a')
- return (c - 'a' + 10) & 0x0f;
- if (c >= 'A')
- return (c - 'A' + 10) & 0x0f;
- return (c - '0') & 0x0f;
- }
注意：当十六进制位串转化为字节数组时，十六进制位串的位数必须是偶数的，因为两个十六进制位串对应一个字节
