byte[]とshort/int/hex間の変換

public class HexToOther {
    /**
     *  byte 
     * @param str
     * @return
     */
    public static byte[] toBytes(String str) {
        if(str == null || str.trim().equals("")) {
            return new byte[0];
        }

        byte[] bytes = new byte[str.length() / 2];
        for(int i = 0; i < str.length() / 2; i++) {
            String subStr = str.substring(i * 2, i * 2 + 2);
            bytes[i] = (byte) Integer.parseInt(subStr, 16);
        }
        return bytes;
    }

    /**
     *  byte[] short
     * @param buf byte 
     * @param asc true
     * @return
     */
    public final static short getShort(byte[] buf, boolean asc) {
        if (buf == null) {
            throw new IllegalArgumentException("byte array is null!");
        }
        if (buf.length > 2) {
            throw new IllegalArgumentException("byte array size > 2 !");
        }
        short r = 0;
        if (asc)
            for (int i = buf.length - 1; i >= 0; i--) {
                r <<= 8;
                r |= (buf[i] & 0x00ff);
            }
        else
            for (int i = 0; i < buf.length; i++) {
                r <<= 8;
                r |= (buf[i] & 0x00ff);
            }
        return r;
    }

    /**
     * byte[] float
     * @param b
     * @param index
     * @return
     */
    public static float byte2float(byte[] b, int index) {
        int l;
        l = b[index + 0];
        l &= 0xff;
        l |= ((long) b[index + 1] << 8);
        l &= 0xffff;
        l |= ((long) b[index + 2] << 16);
        l &= 0xffffff;
        l |= ((long) b[index + 3] << 24);
        return Float.intBitsToFloat(l);
    }

    /**
     * byte[] int
     * @param bytes
     * @return
     */
    public static int byteArrayToInt(byte[] bytes) {
        int value = 0;
        //  
        for (int i = 0; i < 4; i++) {
            int shift = (4 - 1 - i) * 8;
            value += (bytes[i] & 0x000000FF) << shift;//  
        }
        return value;
    }
}