请求信息十六进制显示、请求信息ASCll码显示

private static String byteArr2HexStr(byte[] buf,int len){
        StringBuffer sbuffer = new StringBuffer();
        int cnt = 0;
        for (int i=0;i<len;i++){
            sbuffer.append(byte2Hex(buf[i])+" ");
            cnt++;
            if (cnt % 8 == 0) sbuffer.append(" ");
            if (cnt % 16 == 0) sbuffer.append("\r\n");
        }
        return sbuffer.toString();
    }
    private static String byte2Hex(byte bt){
        int lo = bt & 0b00001111;
        int hi = (bt & 0b11110000) >> 4;
        char clo = arr[lo];
        char chi = arr[hi];
        return chi + "" +clo;
    }

private static String byteArr2HexStr(byte[] buf,int len){
        StringBuffer sbuffer = new StringBuffer();
        StringBuffer sb1 = new StringBuffer();
        StringBuffer sb2 = new StringBuffer();
        int cnt = 0;
        for (int i=0;i<len;i++){
            sb1.append(byte2Hex(buf[i])+" ");
            if (buf[i] >= 0x20 && buf[i] <= 0x7e){
                sb2.append((char) buf[i]);
            }else {
                sb2.append(".");
            }
            cnt++;
            if (cnt % 8 == 0) sb1.append(" ");
            if (cnt % 16 == 0) {
                sbuffer.append(sb1).append(sb2).append("\r\n");
                sb1 = new StringBuffer();
                sb2 = new StringBuffer();
                cnt = 0;
            }
        }
        return sbuffer.toString();
    }