进制转换

Posted 2020-09-29 超人不会飞丿

    private static String hexString = "0123456789ABCDEF";

    /**
     * @Title:bytes2HexString
     * @Description:字节数组转16进制字符串
     * @param b
     *            字节数组
     * @return 16进制字符串
     * @throws
     */
    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);
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }

    /**
     * @Title:hexString2Bytes
     * @Description:16进制字符串转字节数组
     * @param src
     *            16进制字符串
     * @return 字节数组
     * @throws
     */
    public static byte[] hexString2Bytes(String src) {
        int l = src.length() / 2;
        byte[] ret = new byte[l];
        for (int i = 0; i < l; i++) {
            ret[i] = (byte) Integer
                    .valueOf(src.substring(i * 2, i * 2 + 2), 16).byteValue();
        }
        return ret;
    }

    /*
     * 将字符串编码成16进制数字,适用于所有字符（包括中文）
     */
    public static String encode(String str) {
        // 根据默认编码获取字节数组
        byte[] bytes = str.getBytes();
        StringBuilder sb = new StringBuilder(bytes.length * 2);
        // 将字节数组中每个字节拆解成2位16进制整数
        for (int i = 0; i < bytes.length; i++) {
            sb.append(hexString.charAt((bytes[i] & 0xf0) >> 4));
            sb.append(hexString.charAt((bytes[i] & 0x0f) >> 0));
        }
        return sb.toString();
    }

    /*
     * 将COM*转换为对应的数字*，如COM1为1
     */
    public static int ComTransInt(String str) {
        int port = 0;
        if (!(str == null || ("".equals(str)))) {
            if (str.toUpperCase().contains("COM")) {
                port = Integer.parseInt(str.substring(3));
            } else if (str.toUpperCase().contains("USB")) {
                port = 0;
            } else {
                port = -1;
            }
        } else {
            port = -1;
        }
        return port;
    }

    /*
     * 将16进制数字解码成字符串,适用于所有字符（包括中文）
     */
    public static String decode(String bytes) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream(
                bytes.length() / 2);
        // 将每2位16进制整数组装成一个字节
        for (int i = 0; i < bytes.length(); i += 2)
            baos.write((hexString.indexOf(bytes.charAt(i)) << 4 | hexString
                    .indexOf(bytes.charAt(i + 1))));
        return new String(baos.toByteArray());
    }