java - 从计算机读取文件

Question

现在我有这个错误：

线程“main”中的异常 java.lang.ArrayIndexOutOfBoundsException: 4 在 Lotto1.main(Lotto1.java:37)

第 37 行：arr[count][0] = s.next() + ""+ s.next();

import java.io.*;
import java.util.*;

public static void main(String[] args) throws IOException  {

        File f = new File("D:\\Filipe\\Project Final\\src\\database_lotto.txt");
        Scanner s;
        try {
            s = new Scanner(f);

           BufferedReader reader = new BufferedReader(new FileReader(f));
            int lines = 0;
            while (reader.readLine() != null) {
                lines++;
            }
            reader.close();

            arr  = new String[lines][3];

            int count = 0;
            //while theres still another line
            while (s.hasNextLine()){
                arr[count][0] = s.next() + ""+ s.next();
                arr[count][1] = s.next();
                arr[count][2] = s.next();
               count++;                   
            }
        } catch (FileNotFoundException ex) {
           System.out.println("File does not exist");
        }

Answer 1

您没有将正确的路径放入 FileReader 中，仅放入 File f 中，您可以将 f 传递给 Filereader 而不是重复路径：

File f = new File("D:\\database_lotto.txt");
[...]
BufferedReader reader = new BufferedReader(new FileReader(f));