Week 3: Objects, files and exceptions/17b. Read numbers from a file

Numbers are stored in the file numbers.csv. 
One line contains several numbers separated by commas. 
The file could look like this:
1,2,1,2,3
4,3,2,3,2,4,2
1,2,3


Write the method

ArrayList<Integer> allValues()

which reads the numbers from the file, and stores them in a list. 
Finally, the list is returned.



Example method call:
public static void main(String[] args){
    ArrayList<Integer> list = allValues();
    System.out.println(list);
}

Example output:
[1, 2, 1, 2, 3, 4, 3, 2, 3, 2, 4, 2, 1, 2, 3]



==================================


import java.util.Random;
import java.util.ArrayList;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.io.File;*/



public class Test {
    public static void main(String[] args){
        final Random random = new Random();
        
        
        System.out.println("File:");
        for (String s : input) {
            System.out.println("" + s);
        }
        
        
        ArrayList<String> list = new ArrayList<>();
        Scanner scanner = new Scanner(System.in);

       
        System.out.println("Testing the file's numbers...");

        
        ArrayList<Integer> numbers = allValues();
        System.out.println("All values:");
        for (int value : numbers) {
            System.out.println(value);
        }
       
    }
    
    //ADD
    public static ArrayList<Integer> allValues() {
        ArrayList<Integer> list = new ArrayList<>();
        
        try {
            Scanner reader = new Scanner(new File("numbers.csv"));
            // read each line
            while (reader.hasNextLine()) {

                String line = reader.nextLine();
                // split line into array of Integer strings
                String[] values = line.split(",");
                for (String value : values) {
                    list.add(Integer.valueOf(value));
                }
            }
        } 
        catch (FileNotFoundException e) {
            System.out.println("Error: numbers.csv file not found");
        }
        return list;
    }


}








File:
431,668,669,425,27,491,241
751,718,167,454,665,251,958
218,887,235,954,948,947,763
122,306,137,719,905,921,349
Testing the file's numbers...
All values:
431
668
669
425
27
491
241
751
718
167
454
665
251
958
218
887
235
954
948
947
763
122
306
137
719
905
921
349