Java的：从文件整数读阵列 [英] Java: Read array of integers from file

问题描述

说我有一个名为input.txt的一个其中有一帮正整数：

Say i have a file called "input.txt" that has a bunch of positive integers in it:

6
5
6
8
6
2
4

等等....（每行一个整数）

and so on....(one integer per line)

我要读取该文件，并使其成为一个数组。的第一个整数（在这种情况下，6）告诉阵列中的索引或元件的数量，所以6斑点。其他数字填充阵列中的从0开始。因此，在索引0，数为5，在索引1的数目为6，依此类推。

I want to read this file and make it into an array. The first integer (in this case 6) tells the number of indexes or elements in the array, so 6 spots. The other numbers fill in the array starting at 0. So at index 0, the number is 5, at index 1 the number is 6, and so on.

可有人请告诉我如何读取该文件，并使其成为一个数组称为A和每个索引为n返回整数？

Can someone please show me how to read this file and make it into an array called A and return the integers in each index as n?

这是我迄今为止：

import java.io.*;
public class inputFile {
    public static jobScheduleRecursive(int[] A, int i)
    {
        try
    {
        FileReader filereader = new FileReader("input.txt");
        BufferedReader bufferedreader = new BufferedReader(filereader);
        String line = bufferedreader.readLine();
        //While we have read in a valid line
        while (line != null) {
            //Try to parse integer from the String line
            try {
                System.out.println(Integer.parseInt(line));
            } catch (NumberFormatException nfe) {
                System.err.println("Failed to parse integer from line:" + line);
                System.err.println(nfe.getMessage());
                System.exit(1);
            }
            line = bufferedreader.readLine();
        }
    }
    catch(FileNotFoundException filenotfoundexception)
    {
        System.out.println("File not found.");
    }
    catch(IOException ioexception)
    {
        System.out.println("File input error occured!");
        ioexception.printStackTrace();
    }
    return A;
}

我觉得我做的事情完全错误的。请帮助。

I think i'm doing something completely wrong. please help.

推荐答案

使用的 扫描 和<一个href=\"http://download.oracle.com/javase/6/docs/api/java/util/Scanner.html#nextInt%28%29\"><$c$c>Scanner.nextInt()方法，你可以在短短的几行解决这个问题：

Using a Scanner and the Scanner.nextInt() method, you can solve this in just a few lines:

Scanner s = new Scanner(new File("input.txt"));
int[] array = new int[s.nextInt()];
for (int i = 0; i < array.length; i++)
    array[i] = s.nextInt();

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