使用FileReader和Scanner读取文件

Question

我是一个Java初学者,并已阅读类似的问题,但我仍然不知道为什么我的代码显示FileNotFound异常.我的文件在同一目录中.

我的代码是:

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

public class reader {
    public static void main(String[] args) { 
        Scanner in = new Scanner(System.in);
        int x = in.nextInt();
        double y = in.nextDouble();
        float g = in.nextFloat();
        String a = in.next();
        File file = new File("v.txt");
        System.out.println(x + "" + y + "" + g + "" + a); 
        Scanner inFile = new Scanner(new FileReader(file));
        String u = inFile.nextLine();
        System.out.println(file.getAbsolutePath());
        System.out.println(u);
    }
}

错误是:

17: error: unreported exception FileNotFoundException; must be caught or declared to be thrown
     Scanner inFile = new Scanner(new FileReader(file));
                                  ^
1 error

Answer 1

您遇到编译时错误:

error: unreported exception FileNotFoundException; must be caught or declared to be thrown
 Scanner inFile = new Scanner(new FileReader(file));

这是一种修复它的简单方法:

public class reader {
   public static void main(String[] args) throws Exception { 
         //...
   }
}

虽然使用try {...} catch(...){}是处理可能的运行时异常的更好方法.