android bit地图和base64之间的转换

实现手写图片，将图片转化为字符串以及字符串转化为图片，减小发送内容大小

<pre name="code" class="java">	/**	 * bitmap转为base64	 * @param bitmap	 * @return	 */	public static String bitmapToBase64(Bitmap bitmap) {		String result = null;		ByteArrayOutputStream baos = null;		try {			if (bitmap != null) {				baos = new ByteArrayOutputStream();				bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);				baos.flush();				baos.close();				byte[] bitmapBytes = baos.toByteArray();				result = Base64.encodeToString(bitmapBytes, Base64.DEFAULT);			}		} catch (IOException e) {			e.printStackTrace();		} finally {			try {				if (baos != null) {					baos.flush();					baos.close();				}			} catch (IOException e) {				e.printStackTrace();			}		}		return result;	}	/**	 * base64转为bitmap	 * @param base64Data	 * @return	 */	public static Bitmap base64ToBitmap(String base64Data) {		byte[] bytes = Base64.decode(base64Data, Base64.DEFAULT);		return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);	}