public static String getExtension ( final String file ) { final int index = file . indexOf ( SHARP ) ; if ( file . startsWith ( SHARP ) ) { return null ; } else if ( index != - 1 ) { final String fileName = file . substring ( 0 , index ) ; final int fileExtIndex = fileName . lastIndexOf ( DOT ) ; return fileExtIndex != - 1 ? fileName . substring ( fileExtIndex + 1 ) : null ; } else { final int fileExtIndex = file . lastIndexOf ( DOT ) ; return fileExtIndex != - 1 ? file . substring ( fileExtIndex + 1 ) : null ; } }
Get file extension