public String bytes2HexStr(byte[] byteArr) {
        String hexString = "0123456789ABCDEF";
        StringBuilder sb = new StringBuilder(byteArr.length*2);
        for(int i=0;i<byteArr.length;i++)
        {
            sb.append(hexString.charAt((byteArr[i]&0xf0)>>4));
            sb.append(hexString.charAt((byteArr[i]&0x0f)>>0));
        }
        return sb.toString();
    }