Java

How can I create a runtime error?

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How can I create a runtime error?

Mar 26th, 2009

This is my code:

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public boolean SetYear (String year)
{
		if (year.matches("[0-9]{4}"))
		{ 
		_year=year;
		return true;
                }
    return false;
}
public boolean SetYear (String year)
{
		if (year.matches("[0-9]{4}"))
		{ 
		_year=year;
		return true;
                }
    return false;
}

Instead of return false I want to make a runtime error with my massage. Something like "the value must be 4 digits"
How can I do it?

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Ezzaral

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Re: How can I create a runtime error?

Mar 26th, 2009

You throw an exception.

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Re: How can I create a runtime error?

Mar 26th, 2009

Specifically, you probably want to throw an IllegalArgumentException. You can set whatever message you want in the constructor.

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Re: How can I create a runtime error?

Mar 27th, 2009

Or if you want to generate any old runtime error, I've learned plenty of ways to do that in my time programming.

One of the most common is indexing an array by an index too low or too high

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Re: How can I create a runtime error?

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Mar 27th, 2009

Define your own exception handler and use try/catch

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Re: How can I create a runtime error?

Mar 27th, 2009

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Define your own exception handler and use try/catch

Most probably you mean define his own (custom) exception class, but this would be just an overkill.
Ezzaral's suggestion of throwing an IllegalArgumentException for me hits the nail on the head.

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Re: How can I create a runtime error?

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Mar 27th, 2009

He wants a custom error message so it seems like a better idea

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Re: How can I create a runtime error?

Mar 27th, 2009

Last edited by stephen84s; Mar 27th, 2009 at 6:05 am.

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Re: How can I create a runtime error?

Mar 27th, 2009

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Originally Posted by jbennet

He wants a custom error message so it seems like a better idea

You can set the "message" for most (if not all) inbuilt exceptions including the IllegalArgumentException (for whom this constructor can be used which was also mentioned by Ezzaral in his second post).

Last edited by stephen84s; Mar 27th, 2009 at 6:18 am.

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Re: How can I create a runtime error?

#10

Mar 27th, 2009

Yes, generally you only need to create a custom exception if you are wanting to pass along additional information that wouldn't be possible with one of the standard exceptions.