How To Replace Author Names With Numbers

I have a coauthorship network and I want to replace the authors names with numbers.Part of my datadet:

1992,M_DINE,R_LEIGH,P_HUET,A_LINDE,D_LINDE
1992,C_BURGESS,J_CLINE,M_LUTY
1992,M_DINE,R_LEIGH,P_HUET,A_LINDE,D_LINDE
1992,F_ZWIRNER
1992,O_HERNANDEZ
...

I want the result to be sth like this:

1992 1,2,3,4
1992 5,67
....

and a table of mappings

M_DINE 1
R_LEIGH 2
P_HUET 3

....

I give my dataset in csv (or text) format to my program but it says "(The system cannot find the file specified)" even though the file exists.

what should I do?

here is my code:

Java Code: public class ReadCSV {
HashMap<String, Integer> authorList = new HashMap<>();
File file = new File("d:/Course/thesis/predict/whole.scv");
int authorCounter = 0;
public static void main(String[] args) {
ReadCSV obj = new ReadCSV();

[Code]...