Question

我创建了一个程序，该程序应该为Integers读取文本文件并将其放入Arraylist中，然后有很多方法可以对它进行操作。但是，经过一些麻烦的解决之后，我注意到我的程序不会从文本文件中提取整数。有人能指出我正确的方向吗？

    package project1;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;
import java.lang.System;

    public class Main {
        public static void main(String[] Args) {
            Main mainObject = new Main();
            mainObject.run();
        }
        public void run() {
            **ArrayList<Integer> list = new ArrayList<>();
            String fileName = "p01-in.txt";
            Scanner in = new Scanner(fileName);
            while (in.hasNextInt()) {
                list.add(in.nextInt());
                int line = in.nextInt();
                System.out.println("%s  %n" + line);
            }
            in.close();**
            ArrayList<Integer> listRunsUpCount = new ArrayList<>();
            ArrayList<Integer> listRunsDnCount = new ArrayList<>();
            Main findRuns = new Main();
            listRunsUpCount = findRuns.FindRuns(list, 0);
            listRunsDnCount = findRuns.FindRuns(list, 1);
            ArrayList<Integer> listRunsCount = new ArrayList<>();
            Main mergeRuns = new Main();
            listRunsCount = mergeRuns.MergeRuns(listRunsUpCount, 
            listRunsDnCount);
            Main Output = new Main();
            Output.Output("p01-runs.txt", listRunsCount);
        }

Answer 1

您可以使用BufferedReader逐行读取文件内容。

try {
        BufferedReader reader = new BufferedReader(new FileReader(fileName));
        String line=reader.readLine();
        while (line != null) {
            line = reader.readLine();
            list.add(Integer.parseInt(line.trim()));
        }
        reader.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

将文本文件读入ArrayList的Java问题

1 个答案: