@Override
    public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
        // ContentProvider has already checked granted permissions
        final File file = mStrategy.getFileForUri(uri);
        final int fileMode = modeToMode(mode);
        return ParcelFileDescriptor.open(file, fileMode);
    }
By default, FileProvider automatically returns the
{@link ParcelFileDescriptor} for a file associated with a <code>content://</code>
{@link Uri}. To get the {@link ParcelFileDescriptor}, call
{@link android.content.ContentResolver#openFileDescriptor(Uri, String)
ContentResolver.openFileDescriptor}.
<p>
To override this method, you must provide your own subclass of FileProvider.

@param uri  A content URI associated with a file, as returned by
            {@link #getUriForFile(Context, String, File) getUriForFile()}.
@param mode Access mode for the file. May be "r" for read-only access, "rw" for read and
            write access, or "rwt" for read and write access that truncates any existing file.
@return A new {@link ParcelFileDescriptor} with which you can access the file.
replugin-sample/plugin/plugin-demo1/app/src/main/java/com/qihoo360/replugin/sample/demo1/provider/FileProvider.java