How to Convert a File to a Byte Array

I wrote an EJB which performs faxing using gnu-hylafax for Java. The trick is that I needed to convert the file to bytes[] to pass to the EJB. Here is how I did it, but it should work for most files.

    /**
     * Converts a file into a byte[] array.
     * @param file file to be converted
     * @return file converted to {@code byte[]} 
     * @throws java.io.IOException
     */
    public static byte[] getBytesFromFile(final File file) throws IOException {
        InputStream is = new FileInputStream(file);

        // Get the size of the file
        long length = file.length();

        if (length > Integer.MAX_VALUE) {
            /* File is too large. If we are trying to determine the length of the byte[]
             * array, it can only return an int, so we are limited by the file size.
             */
            throw new IOException(file.getName() + " is too large.");
        }

        // Create the byte array to hold the data
        byte[] data = new byte[(int) length];

        // Read in the bytes
        int offset = 0;
        int bytesRead = 0;
        while (offset < data.length &&
                (bytesRead = is.read(data, offset, data.length - offset)) >= 0) {
            offset += bytesRead;
        }

        // Ensure all the bytes have been read in
        if (offset < data.length) {
            throw new IOException("An exception occurred while trying to read + "
                    + file.getName() + " into the byte array.");
        }

        // Close the input stream and return bytes
        is.close();
        return data;
    }
}