android 大小写变换

	private void toUpperCase(byte[] data, int start, int len)	{		int end = start + len;		int dist = 'A' - 'a';		for (int i = start; i < end; i++)		{			if (data[i] >= 'a' && data[i] <= 'z')			{				data[i] += dist;			}		}	}		private void toLowerCase(byte[] data, int start, int len)	{		int end = start + len;		int dist = 'a' - 'A';		for (int i = start; i < end; i++)		{			if (data[i] >= 'A' && data[i] <= 'Z')			{				data[i] += dist;			}		}	}