IOException环路

Question

我需要帮助来弄清楚如何循环我的IOException (在这里，我要求一个文件名，直到输入一个有效的文件名)。我需要一个循环，以某种方式识别输入了一个无效的文件，但不确定如何做到这一点。

import java.util.*;
import java.io.*;
public class JavaGradedLab {
    public static void main(String[] args) throws IOException {

        Scanner inScan, fScan = null;
        int [] A = new int[5];
        inScan = new Scanner(System.in);
        System.out.println("Please enter the file to read from: ");

        try{
            String fName = inScan.nextLine();
            fScan = new Scanner(new File(fName));
        }

        catch (FileNotFoundException ex)
        {
            System.out.println("Your file is invalid -- please re-enter");
        }

        String nextItem;
        int nextInt = 0;
        int i = 0;

        while (fScan.hasNextLine())
        {
            nextItem = fScan.nextLine();
            nextInt = Integer.parseInt(nextItem);
            A[i] = nextInt;
            i++;
        }

        System.out.println("Here are your " + i + " items:");
        for (int j = 0; j < i; j++)
        {
            System.out.println(A[j] + " ");
        }
    }
}

Answer 1

好吧，肯定有人会解释如何通过最佳实践等来改进你的代码，但这是一个非常基本的答案，它本身可能会得到改进(假设你的代码在输入有效的情况下可以工作)：

while(true) {
    try{
        String fName = inScan.nextLine();
        fScan = new Scanner(new File(fName));
        break;
    }
    catch (FileNotFoundException ex)
    {
        System.out.println("Your file is invalid -- please re-enter");
    }
}