public InputStream getStreamArgument ( String name ) throws JournalException { checkOpen ( ) ; File file = ( File ) arguments . get ( name ) ; if ( file == null ) { return null ; } else { try { return new FileInputStream ( file ) ; } catch ( FileNotFoundException e ) { throw new JournalException ( e ) ; } } }
If they ask for an InputStream argument get the File from the arguments map and create an InputStream on that file . If the value from the map is null return null .