Exceptions

When we create an user defined Exception class,

class MyException extends Exception
{
}

Do we have to override any of the methods in the Exception class hierarchy.

What do you think ?

Do we override only the toString() method , to give a meaningful description of the Exception in the stack trace.

Should we override any other methods.

toString() ? No. Instead you can use the Exception(String message) constructor.

Most exception subclasses I create have no methods, only copies of the constructors of its parent class. All these constructors do is call super(arguments). There are usually two or four constructors to copy:
- no arguments for a no-message exception
- String for only a message
- Throwable to wrap a throwable (exception or error) (sometimes absent)
- String, Throwable to wrap a throwable but give a custom error message (sometimes absent)

Whenever I create my own Exceptions I simply create four (overloaded) constructors and leave it at that.

I often create many constructors so I can include (and allow the retrieval of) application-specific properties. Often they're just used in the message, other times they're used by the handler.