java - 异常 try catch 将名称拆分为名字和姓氏

Question

我被要求编写一段程序来使用 try 和 catch 处理异常。虽然，当我运行它时，它不会反射(reflect)我的异常代码，因为应该打印“无效名称”。任何人都可以指出原因吗？如果有人更正我的代码，也将受到热烈欢迎!谢谢。

我需要在以下条件下编写一个程序:

导入 javax.naming.InvalidNameException。写一个方法 public void printName(String name) throws InvalidNameException如果名称没有空格，该方法应抛出 InvalidNameException。写一个驱动来测试。

===============Code result=============
Enter your name: James Dean        
First name: James
Last name: Dean
Enter your name: Brian Smith
First name: Brian
Last name: Smith
Enter your name: RuthKnight
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1
    at Name.printName(Name.java:33)
    at NameApp.main(NameApp.java:17)

==================Method============================
import javax.naming.InvalidNameException;

public class Name{

   public void printName(String name) throws InvalidNameException{

       String [] nameSplit = name.split(" ");
       String first = nameSplit[0];
       String last = nameSplit[1];

       System.out.println("First name: "+first);
       System.out.println("Last name: "+last);      
   }

}

======================Driver========================
import java.util.Scanner;
import javax.naming.InvalidNameException;


public class NameApp{

   public static void main(String[] args) {

      Name aa = new Name();
      Scanner console = new Scanner(System.in);
      try {
         boolean keepRunning= true;

         while(keepRunning){
            System.out.print("Enter your name: ");
            String in = console.nextLine();
            aa.printName(in);
         } 
      }
      catch(InvalidNameException e){
         System.out.println("invalid name");
      }
   }

}

Answer 1

我建议在 Name 类中捕获异常，然后像这样抛出 InvalidNameException:

public void printName(String name) throws InvalidNameException {
    try {
        String[] nameSplit = name.split(" ");
        String first = nameSplit[0];
        String last = nameSplit[1];

        System.out.println("First name: " + first);
        System.out.println("Last name: " + last);
    } catch (ArrayIndexOutOfBoundsException e) {
        throw new InvalidNameException("Missing space in: " + name);
    }
}

更新

运行这段代码:

import javax.naming.InvalidNameException;
public class NameApp{
   public static void main(String[] args) {
      Name aa = new Name();
      try {
            System.out.print("Enter your name: ");
            String in = "George Den";
            aa.printName(in);
            in = "George";
            aa.printName(in);
      }
      catch(InvalidNameException e){
         System.out.println(e.toString());
      }
   }
}

import javax.naming.InvalidNameException;
public class Name {
    public void printName(String name) throws InvalidNameException {
        try {
            String[] nameSplit = name.split(" ");
            String first = nameSplit[0];
            String last = nameSplit[1];
            System.out.println("First name: " + first);
            System.out.println("Last name: " + last);
        } catch (ArrayIndexOutOfBoundsException e) {
            throw new InvalidNameException("Missing space in: " + name);
        }
    }
}

将打印这个:

Enter your name: First name: George Last name: Den

javax.naming.InvalidNameException: Missing space in: George

更新 2

考虑@robjohncox 的建议。此代码不应按原样使用，因为 javax.naming.InvalidNameException 应仅在特定情况下抛出，例如 LDAP 查找和一般的目录特定操作。

最适合您的是对异常对象进行子类化并创建您自己的异常类型(另请参见 How can I write custom Exceptions?):

public class MyCustomNamingException extends Exception {
    public MyCustomNamingException(){
    }
    public MyCustomNamingException(String message){
        super(message);
    }
}

然后在您的代码中使用此 MyCustomNamingException，如之前使用 InvalidNameException

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