Simple List from a text file with Java
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I'm currently studying and also I'm new with Java programming, I have a doubt with nodes and simple lists.
I have to read 2 files that looks like this L1: 1, 5, 8, 4 and L2: 4, 8, 9, 4 and store them in a List not an Array, so I did some code but it's not what I was suppoused to do, so if you could help me to understand the Nodes and Lists to do so I'll really appreciate it because I've been looking and I can't find anything like it.
Also after reading the files another list has to be generated with the sum of the other 2 lists, this sum has to be with the positions of the list so it should look like this L3: 5, 13, 17, 8

This is the code I used:

    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileReader;
    import java.util.StringTokenizer;



    public class Read {

    public static void main(String[] args) {
    // TODO Auto-generated method stub
    FileReader fr, fr2;
    try {
    fr = new FileReader (new File("list1.txt"));
    BufferedReader br = new BufferedReader (fr);
    String line = br.readLine();
		      
    fr2 = new FileReader (new File("list2.txt"));
    BufferedReader br2 = new BufferedReader (fr2);
    String linea2 = br2.readLine();
		      
    StringTokenizer st = new StringTokenizer(line,", ");
    int dimension = st.countTokens();
    int sum=0;
    int sum2=0;
    int total=0;
	  
    int[] arrNum = new int[dimension];
     		      
    while (st.hasMoreTokens()){
    System.out.print("List 1: ");
    for (int i=0; i<arrNum.length; i++ ) {
    arrNum[i] = Integer.parseInt(st.nextToken());
    System.out.print(arrNum[i] + ", ");
    sum += arrNum[i];
    }
    }
    System.out.println("\nThe sum of the first list is: " + sum + "\n");
		      
    StringTokenizer st2 = new StringTokenizer(line2,", ");
    int dimension2 = st2.countTokens();
		      
    int[] arrNum2 = new int[dimension2];
     		      
    while (st2.hasMoreTokens()){
    System.out.print("List 2: ");
    for (int j=0; j<arrNum2.length; j++ ) {
    arrNum2[j] = Integer.parseInt(st2.nextToken());
    System.out.print(arrNum2[j] + ", ");
    sum2 += arrNum2[j];
    }
    }
    System.out.println("\The sum of the second list is: " + suma2);
		      
    total = sum+sum2;
    System.out.println("\nThe sum of the lists are: " + total );
	      
    br.close();
    br2.close();
    }
    catch (Exception e) {
    e.printStackTrace();
    }	    
    }
    }


I hope you can tell em how to do this with the List and Nodes.
Thanks in advance.