EXERCISE 5-4 From
SCJP Study Guide by Kathy Sierra & Bert Bates
Creating an Exception
In this exercise we attempt to create a custom exception. We won't put in any new
methods (it will have only those inherited from Exception), and because it extends
Exception, the compiler considers it a checked exception. The goal of the program
is to determine whether a command-line argument, representing a particular food
(as a
string), is considered bad or OK.
* Let's first create our exception. We will call it BadFoodException. This
exception will be thrown when a bad food is encountered.
* Create an enclosing class called MyException and a main() method,
which will remain empty for now.
* Create a method called checkFood(). It takes a String argument and
throws our exception if it doesn't like the food it was given. Otherwise, it
tells us it likes the food. You can add any foods you aren't particularly fond of
to the list.
* Now in the main() method, you'll get the command-line argument out of
the String array, and then pass that String on to the checkFood() method.
Because it's a checked exception, the checkFood() method must declare
it, and the main() method must handle it (using a try/catch). Do not have
main() declare the exception, because if main() ducks the exception, who
else is back there to catch it?
* As nifty as exception handling is, it's still up to the developer to make
proper use of it. Exception handling makes organizing our code and signaling
problems easy, but the exception handlers still have to be written. You'll find
that even the most complex situations can be handled, and your code will be
reusable, readable, and maintainable.
Is my following solution correct?
Thanks.
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