Java 程序从命令行获取输入，并进行异常处理

Question

再次需要帮助。该程序是将输入作为年龄并根据输入抛出异常。程序运行时会从命令行获取用户的年龄，如果用户没有在命令行输入数字或输入错误，程序应该处理问题。

我的代码是:

 public class Age2 {

    public static void main(String args[]){

        try{
            int age = Integer.parseInt(args[0]);  //taking in an integer input throws NumberFormat Exception if not an integer

            if(age<= 12)
               System.out.println("You are very young");

            else if(age > 12 && age <= 20)
               System.out.println("You are a teenager");

            else
                System.out.println("WOW "+age+" is old");
        }

        catch(NumberFormatException e){   //is input is not an integer, occurs while parsing the command line input argument
            System.out.println("Your input is not a number");

        }catch(ArrayIndexOutOfBoundsException e){ //as takes in input from command line which is stored to a Args array in main, if this array is null implies no input given
            System.out.println("Please enter a number on the command line");
        }

    }   
}//end class

我得到的输出:

但如果用户犯了任何错误，程序也应该显示异常:

“22 22”或“3 kjhk”

见下图:

你能帮我修改一下吗？ 谢谢大家。

Answer 1

如果传递 22 22kjj，args 将有两个元素:22 和 22kjj。

您可以添加一个条件:if(args.length != 1) System.out.println("only one number");