解析网络图片

/**
	 * 
	 * 解析网络图片.
	 */

	private Bitmap decodeBitmapFromNet(final String imagePath) {
		Bitmap bitmap = null;
		InputStream is = null;
		try {
		    //HttpURLConnection conn = (HttpURLConnection) (new URL(imagePath)).openConnection();
			//conn.setDoInput(true);
			//conn.connect(); 
		    //is = conn.getInputStream();

			is = new URL(imagePath).openStream();
			if (is == null) {
				decodeBitmapFailed(R.string.picture_decode_failed);
				return null;
			}
			BitmapFactory.Options options = new BitmapFactory.Options();
			options.inPreferredConfig = Bitmap.Config.RGB_565;
			options.inPurgeable = true;
			options.inInputShareable = true;
			options.inJustDecodeBounds = true;
			if (!imagePath.substring(imagePath.lastIndexOf(".")   1)
			.equalsIgnoreCase(Constants.MPO))
			// options.forceNoHWDoecode = true; // 获取原始分辨率
				Log.i(TAG, "************"   is.markSupported());
			BitmapFactory.decodeStream(is, null, options);
			Log.d(TAG, "from dlna, options "   options.outHeight   " "
					  options.outWidth);
			// 检测图片分辨率.
			if (isLargerThanLimit(options)) {
				closeSilently(is);
				mCanResponse = true;
				return setDefaultPhoto();
			}

			is = new URL(imagePath).openStream();
			//is = conn.getInputStream();
			if (is == null) {
				decodeBitmapFailed(R.string.picture_decode_failed);
				return null;
			}

			// TODO 此处需要做优化,做动态缩放,暂时用固定的缩放比来缩放图片.
			//options.inSampleSize = 4;
			options.inSampleSize = computeSampleSizeLarger(options.outWidth,
					options.outHeight);
			options.inJustDecodeBounds = false;
			// options.forceNoHWDoecode = false;
			Log.d(TAG, "is : "   is);
			bitmap = BitmapFactory.decodeStream(is, null, options);
			if (bitmap == null) {
				Log.d(TAG, "BitmapFactory.decodeStream return null");
				decodeBitmapFailed(R.string.picture_decode_failed);
			}
			closeSilently(is);
			mCanResponse = true;
			return bitmap;
		} catch (MalformedURLException e) {
			Log.e(TAG, "MalformedURLException in decodeBitmap");
			e.printStackTrace();
		} catch (IOException e) {
			Log.e(TAG, "IOException in decodeBitmap");
			e.printStackTrace();
		} finally {
			closeSilently(is);
		}

		decodeBitmapFailed(R.string.picture_decode_failed);
		return null;

	}