Write a Java program that reads file

[Mehwish-S]

Write a Java program that reads the file "X", and prints to the console the file update time, the list of marks for a given UB number and the corresponding “marks gained” value.
So far I have got this and not im totally stuck :/
Help!

 package textcopy;
import java.io.*;
/**
 * This class demonstrates the number of students matching the UB number criterion and the average mark.
 *
 * @author  MSheraz3
 */
public class TextCopy {
    public static void main(String[] args) throws IOException {
        
        BufferedReader reader = new BufferedReader(new FileReader(args[0]));
        BufferedWriter writer = new BufferedWriter(new FileWriter(args[1]));
        
            String line = null; 
                while ((line=reader.readLine()) != null)
                if ( line.split(",")[0].matches("\\d*7\\d*") )
                { writer.write(line); writer.newLine(); }
                reader.close(); writer.close(); 
        
        double sum=0; int counter=0;
        { sum = sum+Integer.parseInt(line.substring(9)); counter = counter+1; }
        
        System.out.println("Students: "+counter+"\nAverage mark: "+sum/counter);
    }
}