Using array Lists

import java.util.*;
import java.io.*;
class StudentNames
{
    private ArrayList<String> names;
    private int numOfStudents;

    public StudentNames(int numOfStudents)
    {
        names = new ArrayList<String>(3);
        this.numOfStudents = numOfStudents;
    }

    void getName() throws Exception {
        Scanner cin = new Scanner(new InputStreamReader(System.in));
        for (int i=0; i<numOfStudents; i++) {
            System.out.println("Student number " + (i+1) + "'s name please!");
            names.add(cin.next());
        }
        System.out.println("Thanks for the names!");
    }

    void writeToScreen() throws Exception {
        int i=0;
        for(String s: names)
            System.out.println( (i+1) + ": " + s );
    }

    void writeToFile(String filename) throws Exception {
        PrintWriter writer = new PrintWriter(filename);
        for(String s: names)
            writer.println(s);
    }

    public static void main(String[] args) throws Exception {
        StudentNames sn = new StudentNames(3);
        try{
            sn.getName();
            sn.writeToScreen();
            sn.writeToFile("abc.txt");
        }catch(IOException e){
            System.out.println(e.getMessage());
        }
    }
}