Question

任何人都可以帮我解决我的问题。我是Java编程的初学者。以前当我没有声明抛出IOException 时，它给了我一个错误：

线程中的异常＆＃34; main＆＃34; java.lang.RuntimeException：无法编译源代码 - 未报告的异常java.io.IOException;必须抓住或宣布被抛出

该计划如下所示：

import java.io.*;

public class addition {
    public static void main(String array[])throws IOException
    {
        InputStreamReader i = new InputStreamReader(System.in);
        BufferedReader b = new BufferedReader(i);
        System.out.println("Enter first number : ");
        int a1 = Integer.parseInt(b.readLine());
          System.out.println("Enter second number : ");
        int a2 = Integer.parseInt(b.readLine());
        int sum = a1 + a2 ;
        System.out.println("addition"+sum);
    }

}

Answer 1

如果在尝试从输入流中读取时发生I / O故障，则BufferedReader函数readLine（）会抛出IOException。在Java中，必须使用try catch语句来处理出现的异常：

import java.io.*;

public class addition {
public static void main(String array[])throws IOException
{
    InputStreamReader i = new InputStreamReader(System.in);
    BufferedReader b = new BufferedReader(i);
    System.out.println("Enter first number : ");

    // Attempt to read in user input.
    try {
        int a1 = Integer.parseInt(b.readLine());
        System.out.println("Enter second number : ");
        int a2 = Integer.parseInt(b.readLine());
        int sum = a1 + a2 ;
        System.out.println("addition"+sum);
    }

    // Should there be some problem reading in input, we handle it gracefully.
    catch (IOException e) {
        System.out.println("Error reading input from user. Exiting now...");
        System.exit(0);
    }
}
}

指定throws IOException

1 个答案: