question: public static String appendImageUrl ( String imageUrl , String suffix ) { if ( TextUtils . isEmpty ( imageUrl ) ) { return "" ; } if ( TextUtils . isEmpty ( suffix ) ) { return imageUrl ; } int dot = imageUrl . lastIndexOf ( '.' ) ; if ( dot == - 1 ) { return imageUrl + suffix ; } else { return imageUrl . substring ( 0 , dot ) + suffix + imageUrl . substring ( dot , imageUrl . length ( ) ) ; } }
target:  Append a suffix to an image URL. Assumes the URL has no suffix (but may have an extension or not.