二进制数据与16进制字符串相互转化方法

二进制数据转化为16进制字符串（中间加的‘：'还有‘；'是为了查看下标，也可以自行去掉）：

public static String bytesToHexString(byte[] src){
StringBuilder stringBuilder = new StringBuilder();
if (src == null || src.length <= 0) {
return null;
}
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xFF;
String hv = Integer.toHexString(v);
 
stringBuilder.append(i + ":");
 
if (hv.length() < 2) {
stringBuilder.append(0);
}
stringBuilder.append(hv + ";");
}
return stringBuilder.toString();
}

16进制字符串转化为二进制数据：

public static byte[] hexStringToByte(String hex) {
int len = (hex.length() / 2);
byte[] result = new byte[len];
char[] achar = hex.toCharArray();
for (int i = 0; i < len; i++) {
int pos = i * 2;
result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));
}
return result;
}
 
private static byte toByte(char c) {
byte b = (byte) "0123456789abcdef".indexOf(c);
return b;
}