根据Uri获取图片绝对路径，解决Android4.4以上版本Uri转换

	/**
	 * 根据Uri获取图片绝对路径，解决Android4.4以上版本Uri转换
	 * @param activity
	 * @param imageUri
	 * @author yaoxing
	 * @date 2014-10-12
	 */
	@TargetApi(19)
	public static String getImageAbsolutePath(Activity context, Uri imageUri) {
		if (context == null || imageUri == null)
			return null;
		if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT && DocumentsContract.isDocumentUri(context, imageUri)) {
			if (isExternalStorageDocument(imageUri)) {
				String docId = DocumentsContract.getDocumentId(imageUri);
				String[] split = docId.split(":");
				String type = split[0];
				if ("primary".equalsIgnoreCase(type)) {
					return Environment.getExternalStorageDirectory() + "/" + split[1];
				}
			} else if (isDownloadsDocument(imageUri)) {
				String id = DocumentsContract.getDocumentId(imageUri);
				Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
				return getDataColumn(context, contentUri, null, null);
			} else if (isMediaDocument(imageUri)) {
				String docId = DocumentsContract.getDocumentId(imageUri);
				String[] split = docId.split(":");
				String type = split[0];
				Uri contentUri = null;
				if ("image".equals(type)) {
					contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
				} else if ("video".equals(type)) {
					contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
				} else if ("audio".equals(type)) {
					contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
				}
				String selection = MediaStore.Images.Media._ID + "=?";
				String[] selectionArgs = new String[] { split[1] };
				return getDataColumn(context, contentUri, selection, selectionArgs);
			}
		} // MediaStore (and general)
		else if ("content".equalsIgnoreCase(imageUri.getScheme())) {
			// Return the remote address
			if (isGooglePhotosUri(imageUri))
				return imageUri.getLastPathSegment();
			return getDataColumn(context, imageUri, null, null);
		}
		// File
		else if ("file".equalsIgnoreCase(imageUri.getScheme())) {
			return imageUri.getPath();
		}
		return null;
	}

	public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
		Cursor cursor = null;
		String column = MediaStore.Images.Media.DATA;
		String[] projection = { column };
		try {
			cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
			if (cursor != null && cursor.moveToFirst()) {
				int index = cursor.getColumnIndexOrThrow(column);
				return cursor.getString(index);
			}
		} finally {
			if (cursor != null)
				cursor.close();
		}
		return null;
	}

	/**
	 * @param uri The Uri to check.
	 * @return Whether the Uri authority is ExternalStorageProvider.
	 */
	public static boolean isExternalStorageDocument(Uri uri) {
		return "com.android.externalstorage.documents".equals(uri.getAuthority());
	}

	/**
	 * @param uri The Uri to check.
	 * @return Whether the Uri authority is DownloadsProvider.
	 */
	public static boolean isDownloadsDocument(Uri uri) {
		return "com.android.providers.downloads.documents".equals(uri.getAuthority());
	}

	/**
	 * @param uri The Uri to check.
	 * @return Whether the Uri authority is MediaProvider.
	 */
	public static boolean isMediaDocument(Uri uri) {
		return "com.android.providers.media.documents".equals(uri.getAuthority());
	}

	/**
	 * @param uri The Uri to check.
	 * @return Whether the Uri authority is Google Photos.
	 */
	public static boolean isGooglePhotosUri(Uri uri) {
		return "com.google.android.apps.photos.content".equals(uri.getAuthority());
	}