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user defined exception

ganapathy gopinathan
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Joined: Aug 10, 2004
Posts: 30
Hi All,

I have a doubt, in user defined exception.
Is that necessary in the user defined exception, that we should have both the error code and error message as attributes? Or can we have only the error message as attribute?

Thanks in advance!!!
Gopinathan
Ernest Friedman-Hill
author and iconoclast
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Joined: Jul 08, 2003
Posts: 24183
    
  34

It's not really necessary to have either (although the Throwable class has a getMessage() method, so if you don't pass a message to your superclass constructor, there will be a message, but it will be an empty one.) In any event, having error codes in user-defined exceptions -- or in any Java exceptions, for that matter -- is rather rare.


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Chengwei Lee
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Joined: Apr 02, 2004
Posts: 884

I have a doubt, in user defined exception.
Is that necessary in the user defined exception, that we should have both the error code and error message as attributes? Or can we have only the error message as attribute?


Are you thinking of using the error code to help identify or classify the types of exceptions? Something similar to what Oracle does? Like whenever we attempt to insert a row with duplicate primary key, an error code would be returned? Or you're thinking along the line of HTTP status codes, the 4xx & 5xx?

The stack trace that comes with the exception would let us know which line the exception was thrown. A descriptive message that we supplied could help us or others that uses our code narrow down or pinpoint the problem.

Also, sometimes, when the name of our custom exceptions are descriptive, just by catching them alone, we would know what went wrong & just have to know which line caused the issue.

Most of the time, a descriptive name & message together with the line number from the stack trace would be sufficient for us to fix the code or handle the exception.



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