android 大小寫轉換

	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;
			}
		}
	}