Java 创建 Costum 异常，这是链接 --> https://codecheck.io/files/wiley/codecheck-bj-4-io-110

Question

https://codecheck.io/files/wiley/codecheck-bj-4-io-110

这是一个代码检查练习，

我们必须创建服装练习，但我找不到方法

java.lang.NullPointerException

我总是遇到这个错误

我试过这个

` 公共类 IllegalNumberOfWheels 扩展了 RuntimeException // TODO: 从适当的异常继承

{
  /**
   TODO: Create two constructors: one with no parameters, and one
   that accepts a message string describing the reason for the exception.
   */
   public IllegalNumberOfWheels()
   {
      
   }
   public IllegalNumberOfWheels(String msg)
   {
      super(msg);
   }
   
}`

Answer 1

你只需要

extend Exception

:

public class IllegalNumberOfWheels extends Exception