int转换为byte数组

 

//将 int 类型数据转成二进制的字符串，不足 int 类型位数时在前面添“0”以凑足位数

 public static String toFullBinaryString(int num) {      char[] chs = new char[Integer.SIZE];       for(int i = 0; i < Integer.SIZE; i++) {            chs[Integer.SIZE - 1 - i]  = (char) n;       }       return new String(chs);           }

</pre><p></p><p>//int型转byte数组 isLE为字节的排列顺序，true为低位在前</p><p></p><pre name="code" class="java">public static byte[] convertInt32(int v, boolean isLE)    {        byte[] bytes = new byte[4];        if (isLE)        {        //高位在后            bytes[3] = (byte) ((v >>> 24) & 0xFF);            bytes[2] = (byte) ((v >>> 16) & 0xFF);            bytes[1] = (byte) ((v >>> 8) & 0xFF);            bytes[0] = (byte) ((v >>> 0) & 0xFF);        }        else        {//高位在前            bytes[0] = (byte) ((v >>> 24) & 0xFF);            bytes[1] = (byte) ((v >>> 16) & 0xFF);            bytes[2] = (byte) ((v >>> 8) & 0xFF);            bytes[3] = (byte) ((v >>> 0) & 0xFF);        }        return bytes;    }

</pre><pre name="code" class="java"><pre name="code" class="java"> /**     * Convert long value to bytes arrays.     *      * @param v long value     * @param isLE Whether endian is LITTLE-ENDIAN.     * @return Bytes arrays.     */    public static byte[] convertLong(long v, boolean isLE)    {        byte[] bytes = new byte[8];        if (isLE)        {            bytes[0] = (byte) (v >>> 0);            bytes[1] = (byte) (v >>> 8);            bytes[2] = (byte) (v >>> 16);            bytes[3] = (byte) (v >>> 24);            bytes[4] = (byte) (v >>> 32);            bytes[5] = (byte) (v >>> 40);            bytes[6] = (byte) (v >>> 48);            bytes[7] = (byte) (v >>> 56);        }        else        {            bytes[0] = (byte) (v >>> 56);            bytes[1] = (byte) (v >>> 48);            bytes[2] = (byte) (v >>> 40);            bytes[3] = (byte) (v >>> 32);            bytes[4] = (byte) (v >>> 24);            bytes[5] = (byte) (v >>> 16);            bytes[6] = (byte) (v >>> 8);            bytes[7] = (byte) (v >>> 0);        }        return bytes;    }

</pre><pre name="code" class="java"><pre name="code" class="java"> /**     * Convert bytes to 32-bits integer by BIG-ENDIAN     *      * @param bytes Bytes array     * @return 32-bits integer     */    public static int convertToInt32(byte[] bytes)    {        if (bytes.length >= 4)        {            return (((bytes[0] & 0xff) << 24) + ((bytes[1] & 0xff) << 16)                    + ((bytes[2] & 0xff) << 8) + ((bytes[3] & 0xff) << 0));        }        return 0;    }

/**     * Convert bytes to long     *      * @param bytes Bytes array     * @return long value     */    public static long convertToLong(byte[] longBuffer)    {        if (longBuffer.length >= 8)        {            return (((long) longBuffer[0] << 56)                    + ((long) (longBuffer[1] & 255) << 48)                    + ((long) (longBuffer[2] & 255) << 40)                    + ((long) (longBuffer[3] & 255) << 32)                    + ((long) (longBuffer[4] & 255) << 24)                    + ((longBuffer[5] & 255) << 16)                    + ((longBuffer[6] & 255) << 8) + ((longBuffer[7] & 255) << 0));        }        return 0;    }

</pre><pre name="code" class="java">/**     * Convert bytes to 32-bits integer     *      * @param bytes Bytes array     * @param isLE Whether bytes are LITTLE-ENDIAN     * @return 32-bits integer     */    public static int convertToInt32(byte[] bytes, boolean isLE)    {        if (bytes.length >= 4)        {            if (isLE)            {                return (((bytes[3] & 0xff) << 24) + ((bytes[2] & 0xff) << 16)                        + ((bytes[1] & 0xff) << 8) + ((bytes[0] & 0xff) << 0));            }            else            {                return (((bytes[0] & 0xff) << 24) + ((bytes[1] & 0xff) << 16)                        + ((bytes[2] & 0xff) << 8) + ((bytes[3] & 0xff) << 0));            }        }        return 0;    }

/**     * Convert 16-bits integer to bytes array     *      * @param 16-bits integer     * @param isLE Whether bytes are LITTLE-ENDIAN     * @return bytes Bytes array     */    public static byte[] convertInt16(int v, boolean isLE)    {        return convertInt16((short) v, isLE);    }

  /**     * Convert 16-bits integer value to bytes arrays.     *      * @param v 16-bits integer value     * @param isLE Whether endian is LITTLE-ENDIAN.     * @return Bytes arrays.     */    public static byte[] convertInt16(short v, boolean isLE)    {        byte[] bytes = new byte[2];        if (isLE)        {            bytes[1] = (byte) ((v >>> 8) & 0xFF);            bytes[0] = (byte) ((v >>> 0) & 0xFF);        }        else        {            bytes[0] = (byte) ((v >>> 8) & 0xFF);            bytes[1] = (byte) ((v >>> 0) & 0xFF);        }        return bytes;    }    /**     * Convert bytes to 16-bits integer by BIG-ENDIAN     *      * @param bytes Bytes array     * @return 16-bits integer     */    public static int convertToInt16(byte[] bytes)    {        if (bytes.length >= 2)        {            return ((bytes[0] & 0xff) << 8) + ((bytes[1] & 0xff) << 0);        }        return 0;    }    /**     * Convert bytes to 16-bits integer     *      * @param bytes Bytes array     * @param isLE Whether bytes are LITTLE-ENDIAN     * @return 16-bits integer     */    public static int convertToInt16(byte[] bytes, boolean isLE)    {        if (bytes.length >= 2)        {            if (isLE)            {                return ((bytes[1] & 0xff) << 8) + ((bytes[0] & 0xff) << 0);            }            else            {                return ((bytes[0] & 0xff) << 8) + ((bytes[1] & 0xff) << 0);            }        }        return 0;    }    /**     * Convert 8-bits integer value to bytes arrays.     *      * @param v 8-bits integer value     * @return Bytes arrays.     */    public static byte[] convertInt8(int v)    {        byte[] bytes = new byte[1];        bytes[0] = (byte) v;        return bytes;    }    public static int convertToInt8(byte[] bytes)    {        if (bytes.length > 0)        {            return (bytes[0] & 0xff);        }        return 0;    }    public static byte[] convertString(String s, String encoding)    {        if (s == null)        {            return new byte[0];        }        try        {            if (encoding == null || "".equals(encoding))            {                return s.getBytes();            }            return s.getBytes(encoding);        }        catch (UnsupportedEncodingException e)        {            throw new OCException("Not support encoding " + encoding, e);        }    }    public static String convertToString(byte[] bytes, String encoding)    {        try        {            if (encoding == null || "".equals(encoding))            {                return new String(bytes);            }            return new String(bytes, encoding);        }        catch (UnsupportedEncodingException e)        {            throw new OCException("Not support encoding " + encoding, e);        }    }    public static byte[] reverseBytes(byte[] bytes)    {        int size = bytes.length;        int len = size / 2;        int max = size - 1;        for (int i = 0; i < len; i++)        {            bytes[i] ^= bytes[max - i];            bytes[max - i] ^= bytes[i];            bytes[i] ^= bytes[max - i];        }        return bytes;    }    /**     * Read bytes from input stream.     *      * @param in Input stream.     * @param len Bytes length.     * @param isLE Whether it's little-endian     * @return Bytes arrays.     * @throws IOException     */    public static byte[] readBytes(InputStream in, int len, boolean isLE)            throws IOException    {        if (len == 0)        {            return new byte[0];        }        byte[] bytes = new byte[len];        int rlen = in.read(bytes);        if (rlen != len)        {            throw new IOException("readBytes length is not match." + len                    + " which is " + rlen);        }        if (isLE)        {            bytes = reverseBytes(bytes);        }        return bytes;    }    /**     * Serial JAVA object to bytes through JDK     *      * @param s Serializable object     * @return serial bytes;     * @throws IOException     */    public static byte[] objectToBytes(Serializable s) throws IOException    {        ByteArrayOutputStream baos = new ByteArrayOutputStream();        ObjectOutputStream oos = new ObjectOutputStream(baos);        try        {            oos.writeObject(s);            oos.flush();            return baos.toByteArray();        }        finally        {            oos.close();        }    }    /**     * Unserial bytes to JAVA object     *      * @param bytes Serial bytes     * @return Java object     * @throws IOException     * @throws ClassNotFoundException     */    public static Object bytesToObject(byte[] bytes) throws IOException,            ClassNotFoundException    {        ByteArrayInputStream bais = new ByteArrayInputStream(bytes);        ObjectInputStream ois = new ObjectInputStream(bais);        try        {            return ois.readObject();        }        finally        {            ois.close();        }    }    public static String toHexString(byte[] coded)    {        if (coded == null)        {            return "";        }        return toHexString(coded, 0, coded.length);    }    public static String toHexString(byte[] coded, int offset, int length)    {        if (coded == null)        {            return "";        }        StringBuilder result = new StringBuilder(length * 3);        for (int i = 0; i < length; i++)        {            int c = coded[i + offset];            if (c < 0)            {                c += 256;            }            int hex1 = c & 0xF;            int hex2 = c >> 4;            result.append(HEX_DIGIT[hex2]);            result.append(HEX_DIGIT[hex1]);            result.append(' ');        }        return result.toString();    }}