什么时候抛出运行时异常？ [英] When to throw runtime exception?

问题描述

最近，我接受了公司的采访，他们给了我一个编码问题。我得到了与纸牌有关的程序，其中一种方法是将纸牌洗牌。因此，我将该程序编写为：

Recently, I had interview with company and they gave me a coding problem. I was given program related to deck of cards and one of the methods was to shuffle the deck of cards. So I wrote the program as:

/** Shuffle the list of cards so that they are in random order 
 * @param d Deck of cards*/
public  static void shuffle(Deck d)
{
    if(d == null)
        throw new IllegalArgumentException();
    Random randomGenerator = new Random();
    List<Card> cards = d.getDeckOfCards();   // cards is basically Linked List.. cards = new LinkedList<Cards>()
    for(int i=0;i<cards.size();i++)
    {
        int randomNumber = randomGenerator.nextInt(52);
        Card c1 = cards.remove(randomNumber);
        Card c2 = cards.remove(0);
        cards.add(0, c1);
        cards.add(randomNumber,c2);
    }       

}

在上面的代码中，我有引发了我最怀疑的 IllegalArgumentException 。在什么情况下实际上应该抛出运行时异常？

In the above code, I have thrown IllegalArgumentException which I'm most doubtful about. Under what conditions should actually throw a runtime exception? Should we actually throw runtime exception?

谢谢

推荐答案

实际上应该抛出运行时异常吗？

Should we actually throw runtime exception?

是的，我们应该这样做。运行时异常有特定的用途-它们发出的编程问题只能通过更改代码来解决，而不是更改程序运行的环境。

Yes, we should. Runtime exception serve a specific purpose - they signal programming problems that can be fixed only by changing code, as opposed to changing the environment in which the program runs.

在什么条件下实际上应该抛出运行时异常？

Under what conditions should actually throw a runtime exception?

当您检测类或方法的方式错误时

When you detect an error with the way your class or method is used, throw a runtime exception.

通常，有两种情况需要抛出运行时异常：

Generally, there are two categories of situations when you need to throw a runtime exception:

• 传递无效的参数值-这是运行时异常的最常见原因。大多数参数验证异常应为运行时异常。 Java提供了几个子类来表示这些特定问题。


• 以错误的顺序调用方法-这是另一个常见原因。如果在类完成初始化或其他一些准备步骤之前无法调用某些方法，则在错误的时间调用会导致运行时异常。

• Passing invalid parameter values - This is the most common cause of runtime exceptions. Most parameter validation exceptions should be runtime exceptions. Java provides several subclasses to signal these specific problems.
• Calling methods in a wrong sequence - This is another common cause. When certain methods cannot be called until a class finishes initialization or some other preparatory steps, calls at the wrong time should cause runtime exceptions.

从这个意义上讲，您的代码很好：它正好适合第一类，即传递无效的参数值。我要做的事情略有不同，就是添加一条消息，说明哪个参数的值无效，但是在您的情况下这并不重要，因为那里只有一个参数。

In this sense, your code is fine: it fits squarely in the first category, i.e. passing invalid parameter values. One thing I would do slightly differently is adding a message to say which parameter had an invalid value, but in your case it is not critical, because there is only one parameter there.

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