byte(字节)根据长度转成KB(千字节)和MB(兆字节)

/**
	 * byte(字节)根据长度转成kb(千字节)和mb(兆字节)
	 * 
	 * @param bytes
	 * @return
	 */
	public static String bytes2kb(long bytes) {
		BigDecimal filesize = new BigDecimal(bytes);
		BigDecimal megabyte = new BigDecimal(1024 * 1024);
		float returnValue = filesize.divide(megabyte, 2, BigDecimal.ROUND_UP)
				.floatValue();
		if (returnValue > 1)
			return (returnValue + "MB");
		BigDecimal kilobyte = new BigDecimal(1024);
		returnValue = filesize.divide(kilobyte, 2, BigDecimal.ROUND_UP)
				.floatValue();
		return (returnValue + "KB");
	}