Java文本文件中的简单列表

Question

I'm currently studying and also I'm new with Java programming, I have a question about nodes and simple lists.

I have to read two 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 . I wrote some code but it's not what I was supposed to do, so if you could help me to understand Nodes and Lists I'd really appreciate it.

Also after reading the files, another list has to be generated with the sum of the other two 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 line2 = 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("\nThe sum of the second list is: " + sum2);

            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 me how to do this with the List and Nodes.

Answer 1

请参阅LinkedList 文档和示例