Ive been given this code as part of a lexical analyser for which i will be coding a syntax analyser - however the file the lexical analyser will be reading will come throught this code:

public static void main(String[] args) throws IOException
{
BufferedReader din = new BufferedReader(new InputStreamReader(System.in)) ;
System.err.print("file? ") ;
System.err.flush() ;
String fileName = din.readLine().trim() ;
LexicalAnalyser lex = new LexicalAnalyser(fileName) ;
} // end of class LexicalAnalyser

The thing is - where is the path name meant to go? It works by replacing fileName however im not so sure why my lecturer has coded the bufferedreader and inputstreamreader